CINXE.COM

<!DOCTYPE html> <html lang="en-US" class="no-js"> <head> <meta charset="UTF-8"><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"NRJS-26d49e9cd1d82010791",applicationID:"529647296"};;/*! For license information please see nr-loader-rum-1.273.1.min.js.LICENSE.txt */ (()=>{var e,t,r={8122:(e,t,r)=>{"use strict";r.d(t,{a:()=>i});var n=r(944);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.R)(3);if(!t||"object"!=typeof t)return(0,n.R)(4);const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{if(null===e[a]){r[a]=null;continue}Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.R)(1,e)}return r}catch(e){(0,n.R)(2,e)}}},2555:(e,t,r)=>{"use strict";r.d(t,{Vp:()=>c,fn:()=>s,x1:()=>u});var n=r(384),i=r(8122);const o={beacon:n.NT.beacon,errorBeacon:n.NT.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){try{const t=c(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}function c(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function u(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.a)(t,o);const r=(0,n.nY)(e);r&&(r.info=a[e])}},9417:(e,t,r)=>{"use strict";r.d(t,{D0:()=>g,gD:()=>h,xN:()=>p});var n=r(993);const i=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var o=r(2614),a=r(944),s=r(384),c=r(8122);const u="[data-nr-mask]",d=()=>{const e={mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{ajax:{deny_list:void 0,block_internal:!0,enabled:!0,harvestTimeSeconds:10,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},feature_flags:[],generic_events:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},harvest:{tooManyRequestsDelay:60},jserrors:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},logging:{enabled:!0,harvestTimeSeconds:10,autoStart:!0,level:n.p_.INFO},metrics:{enabled:!0,autoStart:!0},obfuscate:void 0,page_action:{enabled:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},performance:{capture_marks:!1,capture_measures:!1},privacy:{cookies_enabled:!0},proxy:{assets:void 0,beacon:void 0},session:{expiresMs:o.wk,inactiveMs:o.BB},session_replay:{autoStart:!0,enabled:!1,harvestTimeSeconds:60,preload:!1,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,fix_stylesheets:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){i(t)?e.mask_selector="".concat(t,",").concat(u):""===t||null===t?e.mask_selector=u:(0,a.R)(5,t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){i(t)?e.block_selector+=",".concat(t):""!==t&&(0,a.R)(6,t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,a.R)(7,t)}},session_trace:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},soft_navigations:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},spa:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},ssl:void 0,user_actions:{enabled:!0}}},l={},f="All configuration objects require an agent identifier!";function g(e){if(!e)throw new Error(f);if(!l[e])throw new Error("Configuration for ".concat(e," was never set"));return l[e]}function p(e,t){if(!e)throw new Error(f);l[e]=(0,c.a)(t,d());const r=(0,s.nY)(e);r&&(r.init=l[e])}function h(e,t){if(!e)throw new Error(f);var r=g(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}},3371:(e,t,r)=>{"use strict";r.d(t,{V:()=>f,f:()=>l});var n=r(8122),i=r(384),o=r(6154),a=r(9324);let s=0;const c={buildEnv:a.F3,distMethod:a.Xs,version:a.xv,originTime:o.WN},u={customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,onerror:void 0,ptid:void 0,releaseIds:{},appMetadata:{},session:void 0,denyList:void 0,timeKeeper:void 0,obfuscator:void 0},d={};function l(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!d[e])throw new Error("Runtime for ".concat(e," was never set"));return d[e]}function f(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");d[e]={...(0,n.a)(t,u),...c},Object.hasOwnProperty.call(d[e],"harvestCount")||Object.defineProperty(d[e],"harvestCount",{get:()=>++s});const r=(0,i.nY)(e);r&&(r.runtime=d[e])}},9324:(e,t,r)=>{"use strict";r.d(t,{F3:()=>i,Xs:()=>o,xv:()=>n});const n="1.273.1",i="PROD",o="CDN"},6154:(e,t,r)=>{"use strict";r.d(t,{OF:()=>c,RI:()=>i,WN:()=>d,bv:()=>o,gm:()=>a,mw:()=>s,sb:()=>u});var n=r(1863);const i="undefined"!=typeof window&&!!window.document,o="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=i?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),s=Boolean("hidden"===a?.document?.visibilityState),c=/iPad|iPhone|iPod/.test(a.navigator?.userAgent),u=c&&"undefined"==typeof SharedWorker,d=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Date.now()-(0,n.t)())},1687:(e,t,r)=>{"use strict";r.d(t,{Ak:()=>c,Ze:()=>l,x3:()=>u});var n=r(7836),i=r(3606),o=r(860),a=r(2646);const s={};function c(e,t){const r={staged:!1,priority:o.P3[t]||0};d(e),s[e].get(t)||s[e].set(t,r)}function u(e,t){e&&s[e]&&(s[e].get(t)&&s[e].delete(t),g(e,t,!1),s[e].size&&f(e))}function d(e){if(!e)throw new Error("agentIdentifier required");s[e]||(s[e]=new Map)}function l(e="",t="feature",r=!1){if(d(e),!e||!s[e].get(t)||r)return g(e,t);s[e].get(t).staged=!0,f(e)}function f(e){const t=Array.from(s[e]);t.every((([e,t])=>t.staged))&&(t.sort(((e,t)=>e[1].priority-t[1].priority)),t.forEach((([t])=>{s[e].delete(t),g(e,t)})))}function g(e,t,r=!0){const o=e?n.ee.get(e):n.ee,s=i.i.handlers;if(!o.aborted&&o.backlog&&s){if(r){const e=o.backlog[t],r=s[t];if(r){for(let t=0;e&&t<e.length;++t)p(e[t],r);Object.entries(r).forEach((([e,t])=>{Object.values(t||{}).forEach((t=>{t[0]?.on&&t[0]?.context()instanceof a.y&&t[0].on(e,t[1])}))}))}}o.isolatedBacklog||delete s[t],o.backlog[t]=null,o.emit("drain-"+t,[])}}function p(e,t){var r=e[1];Object.values(t[r]||{}).forEach((t=>{var r=e[0];if(t[0]===r){var n=t[1],i=e[3],o=e[2];n.apply(i,o)}}))}},7836:(e,t,r)=>{"use strict";r.d(t,{P:()=>c,ee:()=>u});var n=r(384),i=r(8990),o=r(3371),a=r(2646),s=r(5607);const c="nr@context:".concat(s.W),u=function e(t,r){var n={},s={},d={},l=!1;try{l=16===r.length&&(0,o.f)(r).isolatedBacklog}catch(e){}var f={on:p,addEventListener:p,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=g(n),c=h(e),d=c.length,l=0;l<d;l++)c[l].apply(a,r);var p=m()[s[e]];p&&p.push([f,e,r,a]);return a},get:v,listeners:h,context:g,buffer:function(e,t){const r=m();if(t=t||"feature",f.aborted)return;Object.entries(e||{}).forEach((([e,n])=>{s[n]=t,t in r||(r[t]=[])}))},abort:function(){f._aborted=!0,Object.keys(f.backlog).forEach((e=>{delete f.backlog[e]}))},isBuffering:function(e){return!!m()[s[e]]},debugId:r,backlog:l?{}:t&&"object"==typeof t.backlog?t.backlog:{},isolatedBacklog:l};return Object.defineProperty(f,"aborted",{get:()=>{let e=f._aborted||!1;return e||(t&&(e=t.aborted),e)}}),f;function g(e){return e&&e instanceof a.y?e:e?(0,i.I)(e,c,(()=>new a.y(c))):new a.y(c)}function p(e,t){n[e]=h(e).concat(t)}function h(e){return n[e]||[]}function v(t){return d[t]=d[t]||e(f,t)}function m(){return f.backlog}}(void 0,"globalEE"),d=(0,n.Zm)();d.ee||(d.ee=u)},2646:(e,t,r)=>{"use strict";r.d(t,{y:()=>n});class n{constructor(e){this.contextId=e}}},9908:(e,t,r)=>{"use strict";r.d(t,{d:()=>n,p:()=>i});var n=r(7836).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},3606:(e,t,r)=>{"use strict";r.d(t,{i:()=>o});var n=r(9908);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.d,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.d);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},3878:(e,t,r)=>{"use strict";function n(e,t){return{capture:e,passive:!1,signal:t}}function i(e,t,r=!1,i){window.addEventListener(e,t,n(r,i))}function o(e,t,r=!1,i){document.addEventListener(e,t,n(r,i))}r.d(t,{DD:()=>o,jT:()=>n,sp:()=>i})},5607:(e,t,r)=>{"use strict";r.d(t,{W:()=>n});const n=(0,r(9566).bz)()},9566:(e,t,r)=>{"use strict";r.d(t,{LA:()=>s,bz:()=>a});var n=r(6154);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n.gm?.crypto||n.gm?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n.gm?.crypto||n.gm?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},2614:(e,t,r)=>{"use strict";r.d(t,{BB:()=>a,H3:()=>n,g:()=>u,iL:()=>c,tS:()=>s,uh:()=>i,wk:()=>o});const n="NRBA",i="SESSION",o=144e5,a=18e5,s={STARTED:"session-started",PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},c={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},u={OFF:0,FULL:1,ERROR:2}},1863:(e,t,r)=>{"use strict";function n(){return Math.floor(performance.now())}r.d(t,{t:()=>n})},944:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.debug&&console.debug("New Relic Warning: https://github.com/newrelic/newrelic-browser-agent/blob/main/docs/warning-codes.md#".concat(e),t)}r.d(t,{R:()=>n})},5284:(e,t,r)=>{"use strict";r.d(t,{t:()=>c,B:()=>s});var n=r(7836),i=r(6154);const o="newrelic";const a=new Set,s={};function c(e,t){const r=n.ee.get(t);s[t]??={},e&&"object"==typeof e&&(a.has(t)||(r.emit("rumresp",[e]),s[t]=e,a.add(t),function(e={}){try{i.gm.dispatchEvent(new CustomEvent(o,{detail:e}))}catch(e){}}({loaded:!0})))}},8990:(e,t,r)=>{"use strict";r.d(t,{I:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},6389:(e,t,r)=>{"use strict";function n(e,t=500,r={}){const n=r?.leading||!1;let i;return(...r)=>{n&&void 0===i&&(e.apply(this,r),i=setTimeout((()=>{i=clearTimeout(i)}),t)),n||(clearTimeout(i),i=setTimeout((()=>{e.apply(this,r)}),t))}}function i(e){let t=!1;return(...r)=>{t||(t=!0,e.apply(this,r))}}r.d(t,{J:()=>i,s:()=>n})},5289:(e,t,r)=>{"use strict";r.d(t,{GG:()=>o,sB:()=>a});var n=r(3878);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.sp)("load",e,t)}function a(e){if(i())return e();(0,n.DD)("DOMContentLoaded",e)}},384:(e,t,r)=>{"use strict";r.d(t,{NT:()=>o,US:()=>d,Zm:()=>a,bQ:()=>c,dV:()=>s,nY:()=>u,pV:()=>l});var n=r(6154),i=r(1863);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return n.gm.NREUM||(n.gm.NREUM={}),void 0===n.gm.newrelic&&(n.gm.newrelic=n.gm.NREUM),n.gm.NREUM}function s(){let e=a();return e.o||(e.o={ST:n.gm.setTimeout,SI:n.gm.setImmediate,CT:n.gm.clearTimeout,XHR:n.gm.XMLHttpRequest,REQ:n.gm.Request,EV:n.gm.Event,PR:n.gm.Promise,MO:n.gm.MutationObserver,FETCH:n.gm.fetch,WS:n.gm.WebSocket}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,i.t)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function d(e,t){a()[e]=t}function l(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},2843:(e,t,r)=>{"use strict";r.d(t,{u:()=>i});var n=r(3878);function i(e,t=!1,r,i){(0,n.DD)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},3434:(e,t,r)=>{"use strict";r.d(t,{YM:()=>c});var n=r(7836),i=r(5607);const o="nr@original:".concat(i.W);var a=Object.prototype.hasOwnProperty,s=!1;function c(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");const a="-"===n.charAt(0);for(let s=0;s<t.length;s++){const c=t[s],u=e[c];d(u)||(e[c]=r(u,a?c+n:n,i,c,o))}},r.flag=o,r;function r(t,r,n,s,c){return d(t)?t:(r||(r=""),nrWrapper[o]=t,function(e,t,r){if(Object.defineProperty&&Object.keys)try{return Object.keys(e).forEach((function(r){Object.defineProperty(t,r,{get:function(){return e[r]},set:function(t){return e[r]=t,t}})})),t}catch(e){u([e],r)}for(var n in e)a.call(e,n)&&(t[n]=e[n])}(t,nrWrapper,e),nrWrapper);function nrWrapper(){var o,a,d,l;try{a=this,o=[...arguments],d="function"==typeof n?n(o,a):n||{}}catch(t){u([t,"",[o,a,s],d],e)}i(r+"start",[o,a,s],d,c);try{return l=t.apply(a,o)}catch(e){throw i(r+"err",[o,a,e],d,c),e}finally{i(r+"end",[o,a,l],d,c)}}}function i(r,n,i,o){if(!s||t){var a=s;s=!0;try{e.emit(r,n,i,t,o)}catch(t){u([t,r,n,i],e)}s=a}}}function u(e,t){t||(t=n.ee);try{t.emit("internal-error",e)}catch(e){}}function d(e){return!(e&&"function"==typeof e&&e.apply&&!e[o])}},993:(e,t,r)=>{"use strict";r.d(t,{ET:()=>o,p_:()=>i});var n=r(860);const i={ERROR:"ERROR",WARN:"WARN",INFO:"INFO",DEBUG:"DEBUG",TRACE:"TRACE"},o="log";n.K7.logging},3969:(e,t,r)=>{"use strict";r.d(t,{TZ:()=>n,XG:()=>s,rs:()=>i,xV:()=>a,z_:()=>o});const n=r(860).K7.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},6630:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewEvent},782:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewTiming},6344:(e,t,r)=>{"use strict";r.d(t,{G4:()=>i});var n=r(2614);r(860).K7.sessionReplay;const i={RECORD:"recordReplay",PAUSE:"pauseReplay",REPLAY_RUNNING:"replayRunning",ERROR_DURING_REPLAY:"errorDuringReplay"};n.g.ERROR,n.g.FULL,n.g.OFF},4234:(e,t,r)=>{"use strict";r.d(t,{W:()=>o});var n=r(7836),i=r(1687);class o{constructor(e,t){this.agentIdentifier=e,this.ee=n.ee.get(e),this.featureName=t,this.blocked=!1}deregisterDrain(){(0,i.x3)(this.agentIdentifier,this.featureName)}}},7603:(e,t,r)=>{"use strict";r.d(t,{j:()=>P});var n=r(860),i=r(2555),o=r(3371),a=r(9908),s=r(7836),c=r(1687),u=r(5289),d=r(6154),l=r(944),f=r(3969),g=r(384),p=r(6344);const h=["setErrorHandler","finished","addToTrace","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start",p.G4.RECORD,p.G4.PAUSE,"log","wrapLogger"],v=["setErrorHandler","finished","addToTrace","addRelease"];var m=r(1863),b=r(2614),y=r(993);var w=r(2646),A=r(3434);function R(e,t,r,n){if("object"!=typeof t||!t||"string"!=typeof r||!r||"function"!=typeof t[r])return(0,l.R)(29);const i=function(e){return(e||s.ee).get("logger")}(e),o=(0,A.YM)(i),a=new w.y(s.P);return a.level=n.level,a.customAttributes=n.customAttributes,o.inPlace(t,[r],"wrap-logger-",a),i}function E(){const e=(0,g.pV)();h.forEach((t=>{e[t]=(...r)=>function(t,...r){let n=[];return Object.values(e.initializedAgents).forEach((e=>{e&&e.api?e.exposed&&e.api[t]&&n.push(e.api[t](...r)):(0,l.R)(38,t)})),n.length>1?n:n[0]}(t,...r)}))}const x={};function _(e,t,g=!1){t||(0,c.Ak)(e,"api");const h={};var w=s.ee.get(e),A=w.get("tracer");x[e]=b.g.OFF,w.on(p.G4.REPLAY_RUNNING,(t=>{x[e]=t}));var E="api-",_=E+"ixn-";function N(t,r,n,o){const a=(0,i.Vp)(e);return null===r?delete a.jsAttributes[t]:(0,i.x1)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),j(E,n,!0,o||null===r?"session":void 0)(t,r)}function T(){}h.log=function(e,{customAttributes:t={},level:r=y.p_.INFO}={}){(0,a.p)(f.xV,["API/log/called"],void 0,n.K7.metrics,w),function(e,t,r={},i=y.p_.INFO){(0,a.p)(f.xV,["API/logging/".concat(i.toLowerCase(),"/called")],void 0,n.K7.metrics,e),(0,a.p)(y.ET,[(0,m.t)(),t,r,i],void 0,n.K7.logging,e)}(w,e,t,r)},h.wrapLogger=(e,t,{customAttributes:r={},level:i=y.p_.INFO}={})=>{(0,a.p)(f.xV,["API/wrapLogger/called"],void 0,n.K7.metrics,w),R(w,e,t,{customAttributes:r,level:i})},v.forEach((e=>{h[e]=j(E,e,!0,"api")})),h.addPageAction=j(E,"addPageAction",!0,n.K7.genericEvents),h.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,o.f)(e).customTransaction=(r||"http://custom.transaction")+t,j(E,"setPageViewName",!0)()},h.setCustomAttribute=function(e,t,r=!1){if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return N(e,t,"setCustomAttribute",r);(0,l.R)(40,typeof t)}else(0,l.R)(39,typeof e)},h.setUserId=function(e){if("string"==typeof e||null===e)return N("enduser.id",e,"setUserId",!0);(0,l.R)(41,typeof e)},h.setApplicationVersion=function(e){if("string"==typeof e||null===e)return N("application.version",e,"setApplicationVersion",!1);(0,l.R)(42,typeof e)},h.start=()=>{try{(0,a.p)(f.xV,["API/start/called"],void 0,n.K7.metrics,w),w.emit("manual-start-all")}catch(e){(0,l.R)(23,e)}},h[p.G4.RECORD]=function(){(0,a.p)(f.xV,["API/recordReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.RECORD,[],void 0,n.K7.sessionReplay,w)},h[p.G4.PAUSE]=function(){(0,a.p)(f.xV,["API/pauseReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.PAUSE,[],void 0,n.K7.sessionReplay,w)},h.interaction=function(e){return(new T).get("object"==typeof e?e:{})};const S=T.prototype={createTracer:function(e,t){var r={},i=this,o="function"==typeof t;return(0,a.p)(f.xV,["API/createTracer/called"],void 0,n.K7.metrics,w),g||(0,a.p)(_+"tracer",[(0,m.t)(),e,r],i,n.K7.spa,w),function(){if(A.emit((o?"":"no-")+"fn-start",[(0,m.t)(),i,o],r),o)try{return t.apply(this,arguments)}catch(e){const t="string"==typeof e?new Error(e):e;throw A.emit("fn-err",[arguments,this,t],r),t}finally{A.emit("fn-end",[(0,m.t)()],r)}}}};function j(e,t,r,i){return function(){return(0,a.p)(f.xV,["API/"+t+"/called"],void 0,n.K7.metrics,w),i&&(0,a.p)(e+t,[(0,m.t)(),...arguments],r?null:this,i,w),r?void 0:this}}function k(){r.e(296).then(r.bind(r,8778)).then((({setAPI:t})=>{t(e),(0,c.Ze)(e,"api")})).catch((e=>{(0,l.R)(27,e),w.abort()}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{S[e]=j(_,e,void 0,g?n.K7.softNav:n.K7.spa)})),h.setCurrentRouteName=g?j(_,"routeName",void 0,n.K7.softNav):j(E,"routeName",!0,n.K7.spa),h.noticeError=function(t,r){"string"==typeof t&&(t=new Error(t)),(0,a.p)(f.xV,["API/noticeError/called"],void 0,n.K7.metrics,w),(0,a.p)("err",[t,(0,m.t)(),!1,r,!!x[e]],void 0,n.K7.jserrors,w)},d.RI?(0,u.GG)((()=>k()),!0):k(),h}var N=r(9417),T=r(8122);const S={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},j={};var k=r(5284);const I=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let O=!1;function P(e,t={},r,n){let{init:a,info:c,loader_config:u,runtime:l={},exposed:f=!0}=t;l.loaderType=r;const p=(0,g.pV)();c||(a=p.init,c=p.info,u=p.loader_config),(0,N.xN)(e.agentIdentifier,a||{}),function(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");j[e]=(0,T.a)(t,S);const r=(0,g.nY)(e);r&&(r.loader_config=j[e])}(e.agentIdentifier,u||{}),c.jsAttributes??={},d.bv&&(c.jsAttributes.isWorker=!0),(0,i.x1)(e.agentIdentifier,c);const h=(0,N.D0)(e.agentIdentifier),v=[c.beacon,c.errorBeacon];O||(h.proxy.assets&&(I(h.proxy.assets),v.push(h.proxy.assets)),h.proxy.beacon&&v.push(h.proxy.beacon),E(),(0,g.US)("activatedFeatures",k.B),e.runSoftNavOverSpa&&=!0===h.soft_navigations.enabled&&h.feature_flags.includes("soft_nav")),l.denyList=[...h.ajax.deny_list||[],...h.ajax.block_internal?v:[]],l.ptid=e.agentIdentifier,(0,o.V)(e.agentIdentifier,l),e.ee=s.ee.get(e.agentIdentifier),void 0===e.api&&(e.api=_(e.agentIdentifier,n,e.runSoftNavOverSpa)),void 0===e.exposed&&(e.exposed=f),O=!0}},8374:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},860:(e,t,r)=>{"use strict";r.d(t,{$J:()=>o,K7:()=>n,P3:()=>i});const n={ajax:"ajax",genericEvents:"generic_events",jserrors:"jserrors",logging:"logging",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",softNav:"soft_navigations",spa:"spa"},i={[n.pageViewEvent]:1,[n.pageViewTiming]:2,[n.metrics]:3,[n.jserrors]:4,[n.spa]:5,[n.ajax]:6,[n.sessionTrace]:7,[n.softNav]:8,[n.sessionReplay]:9,[n.logging]:10,[n.genericEvents]:11},o={[n.pageViewTiming]:"events",[n.ajax]:"events",[n.spa]:"events",[n.softNav]:"events",[n.metrics]:"jserrors",[n.jserrors]:"jserrors",[n.sessionTrace]:"browser/blobs",[n.sessionReplay]:"browser/blobs",[n.logging]:"browser/logs",[n.genericEvents]:"ins"}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.273.1.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.273.1.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),d=0;d<u.length;d++){var l=u[d];if(l.getAttribute("src")==r||l.getAttribute("data-webpack")==t+o){s=l;break}}if(!s){c=!0;var f={296:"sha512-Pel/oKB1rTEfX7XMf0BA3mU/6uscyqtmJfCrvPixhxNsxMn3wc6GmT2qyKBDLZarj8byz09b2DFF7IVK2/b/KQ=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://js-agent.newrelic.com/",(()=>{var e={840:0,374:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.273.1.PROD"]=self["webpackChunk:NRBA-1.273.1.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(8374);var e=i(944),t=i(6344),r=i(9566);class n{agentIdentifier;constructor(e=(0,r.LA)(16)){this.agentIdentifier=e}#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}addPageAction(e,t){return this.#e("addPageAction",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}addRelease(e,t){return this.#e("addRelease",e,t)}log(e,t){return this.#e("log",e,t)}}class o extends n{#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}start(){return this.#e("start")}finished(e){return this.#e("finished",e)}recordReplay(){return this.#e(t.G4.RECORD)}pauseReplay(){return this.#e(t.G4.PAUSE)}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}wrapLogger(e,t,r){return this.#e("wrapLogger",e,t,r)}}var a=i(860),s=i(9417);const c=Object.values(a.K7);function u(e){const t={};return c.forEach((r=>{t[r]=function(e,t){return!0===(0,s.gD)(t,"".concat(e,".enabled"))}(r,e)})),t}var d=i(7603);var l=i(1687),f=i(4234),g=i(5289),p=i(6154),h=i(384);const v=e=>p.RI&&!0===(0,s.gD)(e,"privacy.cookies_enabled");function m(e){return!!(0,h.dV)().o.MO&&v(e)&&!0===(0,s.gD)(e,"session_trace.enabled")}var b=i(6389);class y extends f.W{constructor(e,t,r=!0){super(e.agentIdentifier,t),this.auto=r,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===e.init[this.featureName].autoStart&&(this.auto=!1),this.auto?(0,l.Ak)(e.agentIdentifier,t):this.ee.on("manual-start-all",(0,b.J)((()=>{(0,l.Ak)(e.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator(e)})))}importAggregator(t,r={}){if(this.featAggregate||!this.auto)return;let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let o;try{if(v(this.agentIdentifier)){const{setupAgentSession:e}=await i.e(296).then(i.bind(i,3861));o=e(t)}}catch(t){(0,e.R)(20,t),this.ee.emit("internal-error",[t]),this.featureName===a.K7.sessionReplay&&this.abortHandler?.()}try{if(t.sharedAggregator)await t.sharedAggregator;else{t.sharedAggregator=i.e(296).then(i.bind(i,9337));const{EventAggregator:e}=await t.sharedAggregator;t.sharedAggregator=new e}if(!this.#t(this.featureName,o))return(0,l.Ze)(this.agentIdentifier,this.featureName),void n(!1);const{lazyFeatureLoader:e}=await i.e(296).then(i.bind(i,6103)),{Aggregate:a}=await e(this.featureName,"aggregate");this.featAggregate=new a(t,r),n(!0)}catch(t){(0,e.R)(34,t),this.abortHandler?.(),(0,l.Ze)(this.agentIdentifier,this.featureName,!0),n(!1),this.ee&&this.ee.abort()}};p.RI?(0,g.GG)((()=>o()),!0):o()}#t(e,t){switch(e){case a.K7.sessionReplay:return m(this.agentIdentifier)&&!!t;case a.K7.sessionTrace:return!!t;default:return!0}}}var w=i(6630);class A extends y{static featureName=w.T;constructor(e,t=!0){super(e,w.T,t),this.importAggregator(e)}}var R=i(9908),E=i(2843),x=i(3878),_=i(782),N=i(1863);class T extends y{static featureName=_.T;constructor(e,t=!0){super(e,_.T,t),p.RI&&((0,E.u)((()=>(0,R.p)("docHidden",[(0,N.t)()],void 0,_.T,this.ee)),!0),(0,x.sp)("pagehide",(()=>(0,R.p)("winPagehide",[(0,N.t)()],void 0,_.T,this.ee))),this.importAggregator(e))}}var S=i(3969);class j extends y{static featureName=S.TZ;constructor(e,t=!0){super(e,S.TZ,t),this.importAggregator(e)}}new class extends o{constructor(t,r){super(r),p.gm?(this.features={},(0,h.bQ)(this.agentIdentifier,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(A),this.runSoftNavOverSpa=[...this.desiredFeatures].some((e=>e.featureName===a.K7.softNav)),(0,d.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.R)(21)}get config(){return{info:this.info,init:this.init,loader_config:this.loader_config,runtime:this.runtime}}run(){try{const t=u(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>a.P3[e.featureName]-a.P3[t.featureName])),r.forEach((r=>{if(!t[r.featureName]&&r.featureName!==a.K7.pageViewEvent)return;if(this.runSoftNavOverSpa&&r.featureName===a.K7.spa)return;if(!this.runSoftNavOverSpa&&r.featureName===a.K7.softNav)return;const n=function(e){switch(e){case a.K7.ajax:return[a.K7.jserrors];case a.K7.sessionTrace:return[a.K7.ajax,a.K7.pageViewEvent];case a.K7.sessionReplay:return[a.K7.sessionTrace];case a.K7.pageViewTiming:return[a.K7.pageViewEvent];default:return[]}}(r.featureName).filter((e=>!(e in this.features)));n.length>0&&(0,e.R)(36,{targetFeature:r.featureName,missingDependencies:n}),this.features[r.featureName]=new r(this)}))}catch(t){(0,e.R)(22,t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,h.Zm)();delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator;return r.ee.get(this.agentIdentifier).abort(),!1}}}({features:[A,T,j],loaderType:"lite"})})()})();</script>  <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-5DKHTM4');</script>  <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1" /> <link rel="profile" href="http://gmpg.org/xfn/11"> <link rel="shortcut icon" type="image/x-icon" href="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/favicon.ico" /> <meta name="msapplication-TileColor" content="#A51C30"> <meta name="msapplication-TileImage" content="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/ms/ms-tile-icon.png"> <link rel="apple-touch-icon" href="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/ios/touch-icon-iphone.png"> <link rel="apple-touch-icon" sizes="76x76" href="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/ios/touch-icon-ipad.png"> <link rel="apple-touch-icon" sizes="120x120" href="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/ios/touch-icon-iphone-retina.png"> <link rel="apple-touch-icon" sizes="152x152" href="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/images/ios/touch-icon-ipad-retina.png"> <script>(function(html){html.className = html.className.replace(/\bno-js\b/,'js')})(document.documentElement);</script> <title>Nuclear Air Cleaning: Protecting Public Health | Executive and Continuing Education | Harvard T.H. Chan School of Public Health</title> <meta name='robots' content='max-image-preview:large' /> <link rel='dns-prefetch' href='//www.hsph.harvard.edu' /> <link rel='dns-prefetch' href='//cdnjs.cloudflare.com' /> <link rel='dns-prefetch' href='//fonts.googleapis.com' /> <link rel="alternate" type="application/rss+xml" title="Executive and Continuing Education » Feed" href="https://www.hsph.harvard.edu/ecpe/feed/" /> <script type="text/javascript"> /* <![CDATA[ */ window._wpemojiSettings = {"baseUrl":"https:\/\/s.w.org\/images\/core\/emoji\/15.0.3\/72x72\/","ext":".png","svgUrl":"https:\/\/s.w.org\/images\/core\/emoji\/15.0.3\/svg\/","svgExt":".svg","source":{"concatemoji":"https:\/\/www.hsph.harvard.edu\/ecpe\/wp-includes\/js\/wp-emoji-release.min.js?ver=6.6.1"}}; /*! This file is auto-generated */ !function(i,n){var o,s,e;function c(e){try{var t={supportTests:e,timestamp:(new Date).valueOf()};sessionStorage.setItem(o,JSON.stringify(t))}catch(e){}}function p(e,t,n){e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(t,0,0);var t=new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data),r=(e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(n,0,0),new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data));return t.every(function(e,t){return e===r[t]})}function u(e,t,n){switch(t){case"flag":return n(e,"\ud83c\udff3\ufe0f\u200d\u26a7\ufe0f","\ud83c\udff3\ufe0f\u200b\u26a7\ufe0f")?!1:!n(e,"\ud83c\uddfa\ud83c\uddf3","\ud83c\uddfa\u200b\ud83c\uddf3")&&!n(e,"\ud83c\udff4\udb40\udc67\udb40\udc62\udb40\udc65\udb40\udc6e\udb40\udc67\udb40\udc7f","\ud83c\udff4\u200b\udb40\udc67\u200b\udb40\udc62\u200b\udb40\udc65\u200b\udb40\udc6e\u200b\udb40\udc67\u200b\udb40\udc7f");case"emoji":return!n(e,"\ud83d\udc26\u200d\u2b1b","\ud83d\udc26\u200b\u2b1b")}return!1}function f(e,t,n){var r="undefined"!=typeof WorkerGlobalScope&&self instanceof WorkerGlobalScope?new OffscreenCanvas(300,150):i.createElement("canvas"),a=r.getContext("2d",{willReadFrequently:!0}),o=(a.textBaseline="top",a.font="600 32px Arial",{});return e.forEach(function(e){o[e]=t(a,e,n)}),o}function t(e){var t=i.createElement("script");t.src=e,t.defer=!0,i.head.appendChild(t)}"undefined"!=typeof Promise&&(o="wpEmojiSettingsSupports",s=["flag","emoji"],n.supports={everything:!0,everythingExceptFlag:!0},e=new Promise(function(e){i.addEventListener("DOMContentLoaded",e,{once:!0})}),new Promise(function(t){var n=function(){try{var e=JSON.parse(sessionStorage.getItem(o));if("object"==typeof e&&"number"==typeof e.timestamp&&(new Date).valueOf()<e.timestamp+604800&&"object"==typeof e.supportTests)return e.supportTests}catch(e){}return null}();if(!n){if("undefined"!=typeof Worker&&"undefined"!=typeof OffscreenCanvas&&"undefined"!=typeof URL&&URL.createObjectURL&&"undefined"!=typeof Blob)try{var e="postMessage("+f.toString()+"("+[JSON.stringify(s),u.toString(),p.toString()].join(",")+"));",r=new Blob([e],{type:"text/javascript"}),a=new Worker(URL.createObjectURL(r),{name:"wpTestEmojiSupports"});return void(a.onmessage=function(e){c(n=e.data),a.terminate(),t(n)})}catch(e){}c(n=f(s,u,p))}t(n)}).then(function(e){for(var t in e)n.supports[t]=e[t],n.supports.everything=n.supports.everything&&n.supports[t],"flag"!==t&&(n.supports.everythingExceptFlag=n.supports.everythingExceptFlag&&n.supports[t]);n.supports.everythingExceptFlag=n.supports.everythingExceptFlag&&!n.supports.flag,n.DOMReady=!1,n.readyCallback=function(){n.DOMReady=!0}}).then(function(){return e}).then(function(){var e;n.supports.everything||(n.readyCallback(),(e=n.source||{}).concatemoji?t(e.concatemoji):e.wpemoji&&e.twemoji&&(t(e.twemoji),t(e.wpemoji)))}))}((window,document),window._wpemojiSettings); /* ]]> */ </script> <style id='wp-emoji-styles-inline-css' type='text/css'> img.wp-smiley, img.emoji { display: inline !important; border: none !important; box-shadow: none !important; height: 1em !important; width: 1em !important; margin: 0 0.07em !important; vertical-align: -0.1em !important; background: none !important; padding: 0 !important; } </style> <link rel='stylesheet' id='wp-block-library-css' href='https://www.hsph.harvard.edu/ecpe/wp-includes/css/dist/block-library/style.min.css?ver=6.6.1' type='text/css' media='all' /> <style id='wp-block-library-inline-css' type='text/css'> .has-text-align-justify{text-align:justify;} </style> <link rel='stylesheet' id='mediaelement-css' href='https://www.hsph.harvard.edu/ecpe/wp-includes/js/mediaelement/mediaelementplayer-legacy.min.css?ver=4.2.17' type='text/css' media='all' /> <link rel='stylesheet' id='wp-mediaelement-css' href='https://www.hsph.harvard.edu/ecpe/wp-includes/js/mediaelement/wp-mediaelement.min.css?ver=6.6.1' type='text/css' media='all' /> <style id='jetpack-sharing-buttons-style-inline-css' type='text/css'> .jetpack-sharing-buttons__services-list{display:flex;flex-direction:row;flex-wrap:wrap;gap:0;list-style-type:none;margin:5px;padding:0}.jetpack-sharing-buttons__services-list.has-small-icon-size{font-size:12px}.jetpack-sharing-buttons__services-list.has-normal-icon-size{font-size:16px}.jetpack-sharing-buttons__services-list.has-large-icon-size{font-size:24px}.jetpack-sharing-buttons__services-list.has-huge-icon-size{font-size:36px}@media print{.jetpack-sharing-buttons__services-list{display:none!important}}.editor-styles-wrapper .wp-block-jetpack-sharing-buttons{gap:0;padding-inline-start:0}ul.jetpack-sharing-buttons__services-list.has-background{padding:1.25em 2.375em} </style> <style id='classic-theme-styles-inline-css' type='text/css'> /*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} </style> <style id='global-styles-inline-css' type='text/css'> :root{--wp--preset--aspect-ratio--square: 1;--wp--preset--aspect-ratio--4-3: 4/3;--wp--preset--aspect-ratio--3-4: 3/4;--wp--preset--aspect-ratio--3-2: 3/2;--wp--preset--aspect-ratio--2-3: 2/3;--wp--preset--aspect-ratio--16-9: 16/9;--wp--preset--aspect-ratio--9-16: 9/16;--wp--preset--color--black: #000000;--wp--preset--color--cyan-bluish-gray: #abb8c3;--wp--preset--color--white: #ffffff;--wp--preset--color--pale-pink: #f78da7;--wp--preset--color--vivid-red: #cf2e2e;--wp--preset--color--luminous-vivid-orange: #ff6900;--wp--preset--color--luminous-vivid-amber: #fcb900;--wp--preset--color--light-green-cyan: #7bdcb5;--wp--preset--color--vivid-green-cyan: #00d084;--wp--preset--color--pale-cyan-blue: #8ed1fc;--wp--preset--color--vivid-cyan-blue: #0693e3;--wp--preset--color--vivid-purple: #9b51e0;--wp--preset--gradient--vivid-cyan-blue-to-vivid-purple: linear-gradient(135deg,rgba(6,147,227,1) 0%,rgb(155,81,224) 100%);--wp--preset--gradient--light-green-cyan-to-vivid-green-cyan: linear-gradient(135deg,rgb(122,220,180) 0%,rgb(0,208,130) 100%);--wp--preset--gradient--luminous-vivid-amber-to-luminous-vivid-orange: linear-gradient(135deg,rgba(252,185,0,1) 0%,rgba(255,105,0,1) 100%);--wp--preset--gradient--luminous-vivid-orange-to-vivid-red: linear-gradient(135deg,rgba(255,105,0,1) 0%,rgb(207,46,46) 100%);--wp--preset--gradient--very-light-gray-to-cyan-bluish-gray: linear-gradient(135deg,rgb(238,238,238) 0%,rgb(169,184,195) 100%);--wp--preset--gradient--cool-to-warm-spectrum: linear-gradient(135deg,rgb(74,234,220) 0%,rgb(151,120,209) 20%,rgb(207,42,186) 40%,rgb(238,44,130) 60%,rgb(251,105,98) 80%,rgb(254,248,76) 100%);--wp--preset--gradient--blush-light-purple: linear-gradient(135deg,rgb(255,206,236) 0%,rgb(152,150,240) 100%);--wp--preset--gradient--blush-bordeaux: linear-gradient(135deg,rgb(254,205,165) 0%,rgb(254,45,45) 50%,rgb(107,0,62) 100%);--wp--preset--gradient--luminous-dusk: linear-gradient(135deg,rgb(255,203,112) 0%,rgb(199,81,192) 50%,rgb(65,88,208) 100%);--wp--preset--gradient--pale-ocean: linear-gradient(135deg,rgb(255,245,203) 0%,rgb(182,227,212) 50%,rgb(51,167,181) 100%);--wp--preset--gradient--electric-grass: linear-gradient(135deg,rgb(202,248,128) 0%,rgb(113,206,126) 100%);--wp--preset--gradient--midnight: linear-gradient(135deg,rgb(2,3,129) 0%,rgb(40,116,252) 100%);--wp--preset--font-size--small: 13px;--wp--preset--font-size--medium: 20px;--wp--preset--font-size--large: 36px;--wp--preset--font-size--x-large: 42px;--wp--preset--spacing--20: 0.44rem;--wp--preset--spacing--30: 0.67rem;--wp--preset--spacing--40: 1rem;--wp--preset--spacing--50: 1.5rem;--wp--preset--spacing--60: 2.25rem;--wp--preset--spacing--70: 3.38rem;--wp--preset--spacing--80: 5.06rem;--wp--preset--shadow--natural: 6px 6px 9px rgba(0, 0, 0, 0.2);--wp--preset--shadow--deep: 12px 12px 50px rgba(0, 0, 0, 0.4);--wp--preset--shadow--sharp: 6px 6px 0px rgba(0, 0, 0, 0.2);--wp--preset--shadow--outlined: 6px 6px 0px -3px rgba(255, 255, 255, 1), 6px 6px rgba(0, 0, 0, 1);--wp--preset--shadow--crisp: 6px 6px 0px rgba(0, 0, 0, 1);}:where(.is-layout-flex){gap: 0.5em;}:where(.is-layout-grid){gap: 0.5em;}body .is-layout-flex{display: flex;}.is-layout-flex{flex-wrap: wrap;align-items: center;}.is-layout-flex > :is(*, div){margin: 0;}body .is-layout-grid{display: grid;}.is-layout-grid > :is(*, div){margin: 0;}:where(.wp-block-columns.is-layout-flex){gap: 2em;}:where(.wp-block-columns.is-layout-grid){gap: 2em;}:where(.wp-block-post-template.is-layout-flex){gap: 1.25em;}:where(.wp-block-post-template.is-layout-grid){gap: 1.25em;}.has-black-color{color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-color{color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-color{color: var(--wp--preset--color--white) !important;}.has-pale-pink-color{color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-color{color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-color{color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-color{color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-color{color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-color{color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-color{color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-color{color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-color{color: var(--wp--preset--color--vivid-purple) !important;}.has-black-background-color{background-color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-background-color{background-color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-background-color{background-color: var(--wp--preset--color--white) !important;}.has-pale-pink-background-color{background-color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-background-color{background-color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-background-color{background-color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-background-color{background-color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-background-color{background-color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-background-color{background-color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-background-color{background-color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-background-color{background-color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-background-color{background-color: var(--wp--preset--color--vivid-purple) !important;}.has-black-border-color{border-color: var(--wp--preset--color--black) !important;}.has-cyan-bluish-gray-border-color{border-color: var(--wp--preset--color--cyan-bluish-gray) !important;}.has-white-border-color{border-color: var(--wp--preset--color--white) !important;}.has-pale-pink-border-color{border-color: var(--wp--preset--color--pale-pink) !important;}.has-vivid-red-border-color{border-color: var(--wp--preset--color--vivid-red) !important;}.has-luminous-vivid-orange-border-color{border-color: var(--wp--preset--color--luminous-vivid-orange) !important;}.has-luminous-vivid-amber-border-color{border-color: var(--wp--preset--color--luminous-vivid-amber) !important;}.has-light-green-cyan-border-color{border-color: var(--wp--preset--color--light-green-cyan) !important;}.has-vivid-green-cyan-border-color{border-color: var(--wp--preset--color--vivid-green-cyan) !important;}.has-pale-cyan-blue-border-color{border-color: var(--wp--preset--color--pale-cyan-blue) !important;}.has-vivid-cyan-blue-border-color{border-color: var(--wp--preset--color--vivid-cyan-blue) !important;}.has-vivid-purple-border-color{border-color: var(--wp--preset--color--vivid-purple) !important;}.has-vivid-cyan-blue-to-vivid-purple-gradient-background{background: var(--wp--preset--gradient--vivid-cyan-blue-to-vivid-purple) !important;}.has-light-green-cyan-to-vivid-green-cyan-gradient-background{background: var(--wp--preset--gradient--light-green-cyan-to-vivid-green-cyan) !important;}.has-luminous-vivid-amber-to-luminous-vivid-orange-gradient-background{background: var(--wp--preset--gradient--luminous-vivid-amber-to-luminous-vivid-orange) !important;}.has-luminous-vivid-orange-to-vivid-red-gradient-background{background: var(--wp--preset--gradient--luminous-vivid-orange-to-vivid-red) !important;}.has-very-light-gray-to-cyan-bluish-gray-gradient-background{background: var(--wp--preset--gradient--very-light-gray-to-cyan-bluish-gray) !important;}.has-cool-to-warm-spectrum-gradient-background{background: var(--wp--preset--gradient--cool-to-warm-spectrum) !important;}.has-blush-light-purple-gradient-background{background: var(--wp--preset--gradient--blush-light-purple) !important;}.has-blush-bordeaux-gradient-background{background: var(--wp--preset--gradient--blush-bordeaux) !important;}.has-luminous-dusk-gradient-background{background: var(--wp--preset--gradient--luminous-dusk) !important;}.has-pale-ocean-gradient-background{background: var(--wp--preset--gradient--pale-ocean) !important;}.has-electric-grass-gradient-background{background: var(--wp--preset--gradient--electric-grass) !important;}.has-midnight-gradient-background{background: var(--wp--preset--gradient--midnight) !important;}.has-small-font-size{font-size: var(--wp--preset--font-size--small) !important;}.has-medium-font-size{font-size: var(--wp--preset--font-size--medium) !important;}.has-large-font-size{font-size: var(--wp--preset--font-size--large) !important;}.has-x-large-font-size{font-size: var(--wp--preset--font-size--x-large) !important;} :where(.wp-block-post-template.is-layout-flex){gap: 1.25em;}:where(.wp-block-post-template.is-layout-grid){gap: 1.25em;} :where(.wp-block-columns.is-layout-flex){gap: 2em;}:where(.wp-block-columns.is-layout-grid){gap: 2em;} :root :where(.wp-block-pullquote){font-size: 1.5em;line-height: 1.6;} </style> <link rel='stylesheet' id='hsph-plugin-multisite-tweaks-styles-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-multisite-tweaks/assets/css/hsph-plugin-multisite-tweaks.css?ver%5BVersion%5D=1.2.2' type='text/css' media='all' /> <link rel='stylesheet' id='hsph_page_elements_styles-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-page-elements/assets/css/plugin-page-elements.css?ver=1.2.6' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-plugin-tagging-topics-pages-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-tagging/assets/css/topics.css?ver=1.1.5' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-table-sortable-css-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-tinymce-tweaks/assets/css/hsph-table-sortable.css?ver=1.1.1' type='text/css' media='all' /> <link rel='stylesheet' id='dashicons-css' href='https://www.hsph.harvard.edu/ecpe/wp-includes/css/dashicons.min.css?ver=6.6.1' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-bootstrap-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-design-system/assets/css/hsph-bootstrap-no-conflict.css?ver=1.4.12' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-ui-shortcodes-style-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-ui-shortcodes/assets/css/hsph-ui-shortcodes.css?ver=1.6.11' type='text/css' media='all' /> <link rel='stylesheet' id='search-filter-plugin-styles-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/search-filter-pro/public/assets/css/search-filter.min.css?ver=2.5.13' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-style-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/style.css?ver=1.3.101' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-fontawesome-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-design-system/assets/css/hsph-fontawesome.css?ver=1.4.12' type='text/css' media='all' /> <link rel='stylesheet' id='ecpe-child-style-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016-child-ecpe/style.css?ver=1.1.14' type='text/css' media='all' />  <link rel='stylesheet' id='hsph-fonts-css' href='https://fonts.googleapis.com/css?family=Merriweather%3A300%2C400%2C700%2C300italic%2C400italic%2C700italic%7CInconsolata%3A400&subset=latin%2Clatin-ext&ver=1.3.101' type='text/css' media='all' /> <link rel='stylesheet' id='genericons-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/jetpack/_inc/genericons/genericons/genericons.css?ver=3.1' type='text/css' media='all' /> <link rel='stylesheet' id='hsph-people-research-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/css/people-research.css?ver=1.3.101' type='text/css' media='all' />   <link rel='stylesheet' id='hsph-sharing-buttons-styles-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-social//assets/css/hsph-sharing-buttons.css?ver%5BVersion%5D=1.0.1' type='text/css' media='all' /> <link rel='stylesheet' id='jetpack_css-css' href='https://www.hsph.harvard.edu/ecpe/wp-content/plugins/jetpack/css/jetpack.css?ver=13.3.1' type='text/css' media='all' /> <script type="text/javascript" id="wp-sentry-browser-js-extra"> /* <![CDATA[ */ var wp_sentry = {"environment":"prod","release":"v6.6.1.5","context":{"tags":{"wordpress":"6.6.1","language":"en-US"}},"blacklistUrls":["https:\/\/theforum.sph.harvard.edu\/","https:\/\/theforum.sph.harvard.edu\/","https:\/\/p3.3playmedia.com\/","https:\/\/static.3playmedia.com\/","http:\/\/p3.3playmedia.com\/","http:\/\/static.3playmedia.com\/","https:\/\/www.hsph.harvard.edu\/voices\/","regex:3playmedia","regex:theforum\\.sph\\.harvard","regex:theforum\\.sph\\.harvard","harvard\\\\.edu\\\/voices\\\/","harvard\\.edu\\\/voices\\\/"],"denyUrls":["https:\/\/theforum.sph.harvard.edu\/","https:\/\/theforum.sph.harvard.edu\/","https:\/\/p3.3playmedia.com\/","https:\/\/static.3playmedia.com\/","http:\/\/p3.3playmedia.com\/","http:\/\/static.3playmedia.com\/","https:\/\/www.hsph.harvard.edu\/voices\/","regex:theforum\\.sph\\.harvard","regex:theforum\\.sph\\.harvard","harvard\\\\.edu\\\/voices\\\/","harvard\\.edu\\\/voices\\\/"],"dsn":"https:\/\/1cf5486bca3949988f6ee887a807ff7c@o259296.ingest.sentry.io\/1856593"}; /* ]]> */ </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/wp-sentry-integration/public/wp-sentry-browser.min.js?ver=7.12.0" id="wp-sentry-browser-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/jquery-updater/js/jquery-3.7.1.min.js?ver=3.7.1" id="jquery-core-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/jquery-updater/js/jquery-migrate-3.4.1.min.js?ver=3.4.1" id="jquery-migrate-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-includes/js/jquery/ui/core.min.js?ver=1.13.3" id="jquery-ui-core-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-includes/js/jquery/ui/tabs.min.js?ver=1.13.3" id="jquery-ui-tabs-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-includes/js/jquery/ui/accordion.min.js?ver=1.13.3" id="jquery-ui-accordion-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-ui-shortcodes/assets/js/hsph-ui-shortcodes.js?ver=1.6.11" id="hsph-ui-shortcodes-scripts-js"></script> <script type="text/javascript" id="search-filter-plugin-build-js-extra"> /* <![CDATA[ */ var SF_LDATA = {"ajax_url":"https:\/\/www.hsph.harvard.edu\/ecpe\/wp-admin\/admin-ajax.php","home_url":"https:\/\/www.hsph.harvard.edu\/ecpe\/","extensions":[]}; /* ]]> */ </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/search-filter-pro/public/assets/js/search-filter-build.min.js?ver=2.5.13" id="search-filter-plugin-build-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/search-filter-pro/public/assets/js/chosen.jquery.min.js?ver=2.5.13" id="search-filter-plugin-chosen-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/js/typekit.js?ver=1.3.101" id="hsph-typekit-js"></script>  <link rel="https://api.w.org/" href="https://www.hsph.harvard.edu/ecpe/wp-json/" /><link rel="alternate" title="JSON" type="application/json" href="https://www.hsph.harvard.edu/ecpe/wp-json/wp/v2/posts/2870" /><link rel="EditURI" type="application/rsd+xml" title="RSD" href="https://www.hsph.harvard.edu/ecpe/xmlrpc.php?rsd" /> <link rel="canonical" href="https://www.hsph.harvard.edu/ecpe/air-cleaning-systems-nuclear-power/" /> <link rel='shortlink' href='https://www.hsph.harvard.edu/ecpe/?p=2870' /> <link rel="alternate" title="oEmbed (JSON)" type="application/json+oembed" href="https://www.hsph.harvard.edu/ecpe/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F" /> <link rel="alternate" title="oEmbed (XML)" type="text/xml+oembed" href="https://www.hsph.harvard.edu/ecpe/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&format=xml" />  <script type="text/javascript"> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','https://www.google-analytics.com/analytics.js','ga'); ga( 'create', 'UA-16396394-1', 'hsph.harvard.edu', 'trackern1'); ga( 'trackern1.require', 'displayfeatures'); ga( 'trackern1.require', 'linkid'); ga( 'trackern1.set', 'dimension1', 'signed_out' ); ga( 'trackern1.set', 'dimension2', 'none' ); ga( 'trackern1.send', 'pageview'); ga( 'create', ' UA-44468534-1', 'hsph.harvard.edu', 'trackern2'); ga( 'trackern2.require', 'displayfeatures'); ga( 'trackern2.require', 'linkid'); ga( 'trackern2.set', 'dimension1', 'signed_out' ); ga( 'trackern2.set', 'dimension2', 'none' ); ga( 'trackern2.send', 'pageview'); ga( 'create', 'UA-52313725-1', 'auto', 'trackers1'); ga( 'trackers1.require', 'displayfeatures'); ga( 'trackers1.require', 'linkid'); ga( 'trackers1.set', 'dimension1', 'signed_out' ); ga( 'trackers1.set', 'dimension2', 'none' ); ga( 'trackers1.send', 'pageview'); </script>   <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-XL6K');</script>  <meta http-equiv="content-language" content="en-us" /> <meta name="copyright" content="Copyright (c) 2024 The President and Fellows of Harvard College" /><meta name="description" content="Testing and certifying systems containing HEPA filtration and gas adsorption systems for nuclear and non-nuclear applications" />  <meta property="og:type" content="article" /> <meta property="og:title" content="How Foolproof Air Cleaning Systems at Nuclear Power Plants Protect Public Health" /> <meta property="og:url" content="https://www.hsph.harvard.edu/ecpe/air-cleaning-systems-nuclear-power/" /> <meta property="og:description" content="Air cleaning systems are often the final line of defense in the event of radiological release or nuclear disaster. The role of air cleaning systems in nuclear accidents is vital in minimizing publi…" /> <meta property="article:published_time" content="2017-06-14T13:17:09+00:00" /> <meta property="article:modified_time" content="2023-10-03T15:21:53+00:00" /> <meta property="og:site_name" content="Executive and Continuing Education" /> <meta property="og:image" content="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg" /> <meta property="og:image:width" content="750" /> <meta property="og:image:height" content="500" /> <meta property="og:image:alt" content="" /> <meta property="og:locale" content="en_US" /> <meta name="twitter:site" content="@harvardchansph" /> <meta name="twitter:text:title" content="How Foolproof Air Cleaning Systems at Nuclear Power Plants Protect Public Health" /> <meta name="twitter:image" content="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg?w=640" /> <meta name="twitter:card" content="summary_large_image" />  <link rel="icon" href="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2020/09/shield-favicon-150x150.png" sizes="32x32" /> <link rel="icon" href="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2020/09/shield-favicon-300x300.png" sizes="192x192" /> <link rel="apple-touch-icon" href="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2020/09/shield-favicon-300x300.png" /> <meta name="msapplication-TileImage" content="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2020/09/shield-favicon-300x300.png" /> <style type="text/css" id="wp-custom-css"> body.post-type-archive-programs div.taxonomy-description { display: none; } input.sf-input-checkbox { margin-right: 0; } body.post-type-archive-faculty div.taxonomy-description { display: none; } .program-listing { border-bottom: 1px solid #d1d1d1; margin-bottom: 0; padding-bottom: 1.5em !important; } /* Chrome 29+ ( Not targeting Chrome only ) */ @media all and (-webkit-min-device-pixel-ratio:0) and (min-resolution: .001dpcm) { /*HCPMO/ article#post-285 #agenda > div > div > table > tbody > tr:nth-child(1) > th:nth-child(1){ display:none } /*BCV article#post-285 #agenda > div > div > table > tbody > tr:nth-child(1) > th:nth-child(1){ display:none } */ } #post-309 #misc, #post-309 #program-tabs > ul > li:nth-child(7){ display:none; } #post-299 #misc, #post-299 #program-tabs > ul > li:nth-child(7){ display:none; } .postid-313 li[aria-controls=faculty]{ display:none !important; } #post-10915 .brochure-request{ /*display:none;*/ } @media screen and (min-width: 650px) { /* Manually style iteration info/summary area to avoid unwanted styles when hsph-bootstrap is applied. */ .ecpe-iteration-section, .ecpe-iteration-section :is(section, div)>div { display: flex; flex-direction: column; } .ecpe-iteration-section :is(section, div) { display: flex; flex-direction: row; } } </style> <style id="kirki-inline-styles"></style></head> <body class="post-template-default single single-post postid-2870 single-format-standard has-sidebar group-blog">  <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-5DKHTM4" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>  <div class="wrapper" id="wrapper"> <div id="navbar" class="navbar"> <div id="nav-utility-menu" class="nav-utility-menu"></div> <div id="nav-primary-menu" class="nav-primary-menu"></div> <div id="nav-audience-menu" class="nav-audience-menu"></div> </div> <button id="main-menu-toggle" class="main-menu-toggle">Menu</button> <button id="main-menu-caption" class="main-menu-caption"><span id="main-menu-caption-text" class="main-menu-caption-text">Close Menu</span></button> <div id="page" class="site"> <a class="skip-link screen-reader-text" href="#content">Skip to content</a> <header id="masthead" class="site-header" role="banner"> <div id="audience-bar"> <div id="site-audience-menu" class="site-audience-menu"> <span class="information-for">Information For:</span> <nav id="audience-navigation" class="audience-navigation" role="navigation" aria-label="Audience Menu"> <div class="menu-audience-menu-container"><ul id="menu-audience-menu" class="hsph-audience-menu"><li id="menu-item-253" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-253"><a href="/ecpe/audiences/clinicians/">Clinicians</a></li> <li id="menu-item-254" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-254"><a href="/ecpe/audiences/ehs-professionals/">EHS Professionals</a></li> <li id="menu-item-255" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-255"><a href="/ecpe/audiences/academics/">Academics</a></li> <li id="menu-item-256" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-256"><a href="/ecpe/audiences/executives/">Executives</a></li> <li id="menu-item-257" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-257"><a href="/ecpe/audiences/government-employees/">Gov Employees</a></li> <li id="menu-item-258" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-258"><a href="/ecpe/programs/">More</a></li> </ul></div> </nav> </div> <div id="index-search"> <div id="site-atoz-menu" class="site-atoz-menu"> <nav id="atoz-navigation" class="atoz-navigation" role="navigation" aria-label="A to Z Menu"> <div class="menu-upper-right-container"><ul id="menu-upper-right" class="hsph-atoz-menu"><li id="menu-item-497" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-497"><a href="https://www.hsph.harvard.edu/ecpe/faq/">FAQs</a></li> </ul></div> </nav> </div> <div id="search"> <form role="search" method="get" class="search-form" action="https://www.hsph.harvard.edu/ecpe/"> <label> <span class="screen-reader-text">Search for:</span> <input type="search" class="search-field" placeholder="Search …" value="" name="s" id="q" title="Search for:" /> </label> <button type="submit" value="Search" alt="Search" class="search-submit"> </button> </form> </div> </div> </div> <div class="site-header-main"> <div class="site-branding"> <div class="site-title"><a href="https://www.hsph.harvard.edu/ecpe/" rel="home">Harvard T.H. Chan School of Public Health</a></div> </div> <div id="site-utility-menu" class="site-utility-menu"> <nav id="utility-navigation" class="utility-navigation" role="navigation" aria-label="Utility Menu"> <div class="menu-utility-links-container"><ul id="menu-utility-links" class="hsph-utility-menu"><li id="menu-item-34" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-34"><a href="https://sph-crm-ecpe.my.site.com/login">Attendee Portal Login</a></li> <li id="menu-item-36" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-36"><a href="https://www.hsph.harvard.edu/translation">Division of Policy Translation and Leadership Development</a></li> </ul></div> </nav> </div> </div> <div id="site-header-menu" class="site-header-menu"> <nav id="site-navigation" class="main-navigation" role="navigation" aria-label="Primary Menu"> <div class="menu-main-menu-container"><ul id="menu-main-menu" class="hsph-primary-menu"><li id="menu-item-184" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-184"><a href="/ecpe/programs/">Programs for Individuals</a></li> <li id="menu-item-5209" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-5209"><a href="https://www.hsph.harvard.edu/ecpe/programs-for-organizations/">Programs for Organizations</a></li> <li id="menu-item-7" class="menu-item menu-item-type-post_type menu-item-object-page current_page_parent menu-item-7"><a href="https://www.hsph.harvard.edu/ecpe/news/">News & Resources</a></li> <li id="menu-item-41" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-41"><a href="https://execed2.sph.harvard.edu/executive-education-program-portfolio">Portfolio Download</a></li> <li id="menu-item-31" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-31"><a href="https://www.hsph.harvard.edu/ecpe/about/">About Executive Education</a></li> </ul></div> </nav> </div> </header> <div id="content" class="site-content">  <div id="breadcrumbs"> <span property="itemListElement" typeof="ListItem"><a property="item" typeof="WebPage" title="Go to Executive and Continuing Education." href="https://www.hsph.harvard.edu/ecpe" class="main-home"><span property="name">Executive and Continuing Education</span></a><meta property="position" content="1"></span> > <span property="itemListElement" typeof="ListItem"><a property="item" typeof="WebPage" title="Go to News & Resources." href="https://www.hsph.harvard.edu/ecpe/news/" class="post-root post post-post"><span property="name">News & Resources</span></a><meta property="position" content="2"></span> > <span property="itemListElement" typeof="ListItem"><a property="item" typeof="WebPage" title="Go to the Occupational, Environmental Health, and Safety category archives." href="https://www.hsph.harvard.edu/ecpe/category/environmental-health-and-safety/" class="taxonomy category"><span property="name">Occupational, Environmental Health, and Safety</span></a><meta property="position" content="3"></span> > <span property="itemListElement" typeof="ListItem"><span property="name">How Foolproof Air Cleaning Systems at Nuclear Power Plants Protect Public Health</span><meta property="position" content="4"></span></div> <div id="primary" class="content-area"> <div id="left-nav" class="left-nav" role="navigation">  <div class="left-collapse-container">  <div id="site-left-menu" class="site-left-menu"> <nav id="site-left-nav" class="left-navigation" role="navigation" aria-label="Section Menu"> <div class="menu-left-menu-container"><ul id="menu-left-menu" class="hsph-lefthand-menu"><li id="menu-item-501" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-501"><a href="/ecpe/programs/">Programs for Individuals</a></li> <li id="menu-item-21263" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-21263"><a href="https://www.hsph.harvard.edu/ecpe/business-applications-for-ai-in-health-care-certificate-of-specialization/">Business Applications for AI in Health Care Certificate of Specialization</a></li> <li id="menu-item-23449" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-23449"><a href="https://www.hsph.harvard.edu/ecpe/executive-health-care-in-leadership-certificate-of-specialization/">Executive Leadership in Health Care | Certificate of Specialization</a></li> <li id="menu-item-24868" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children menu-item-24868"><a href="https://www.hsph.harvard.edu/ecpe/programs/principles-and-practice-of-clinical-research/">Principles and Practice of Clinical Research</a> <ul class="sub-menu"> <li id="menu-item-24871" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24871"><a href="https://www.hsph.harvard.edu/ecpe/about-ppcr/">About PPCR</a></li> <li id="menu-item-24873" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24873"><a href="https://www.hsph.harvard.edu/ecpe/testimonials/">Testimonials</a></li> <li id="menu-item-24876" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24876"><a href="https://www.hsph.harvard.edu/ecpe/ppcr-locations/">International Sites</a></li> <li id="menu-item-24874" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24874"><a href="https://www.hsph.harvard.edu/ecpe/learning-model/">Learning Model</a></li> <li id="menu-item-24869" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24869"><a href="https://www.hsph.harvard.edu/ecpe/ppcr-frequently-asked-questions/">Frequently Asked Questions</a></li> <li id="menu-item-24870" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24870"><a href="https://www.hsph.harvard.edu/ecpe/faculty-members/">Faculty Members</a></li> <li id="menu-item-24872" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24872"><a href="https://www.hsph.harvard.edu/ecpe/teaching-assistants/">Teaching Assistants</a></li> <li id="menu-item-24875" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-24875"><a href="https://www.hsph.harvard.edu/ecpe/team/">Team</a></li> <li id="menu-item-24877" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-24877"><a href="https://execed2.sph.harvard.edu/ppcr-contact-us">Contact Us</a></li> </ul> </li> <li id="menu-item-502" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-502"><a href="https://www.hsph.harvard.edu/ecpe/faq/">Frequently Asked Questions</a></li> <li id="menu-item-828" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-828"><a href="/ecpe/faculty/">Faculty Directory</a></li> </ul></div> </nav> </div> <div id="related-programs"> <div class="section-title"> <h4>Related Programs</h4> </div> <div class="related-program"> <h4 class="related-program-title">In-Place Filter Testing Workshop</h4> <span class='dates iteration-flex-item'><span class='start'>July 21</span> – <span class='end'>25, 2025</span></span> <a href="https://www.hsph.harvard.edu/ecpe/programs/in-place-filter-testing-workshop/" class="related-program-learn-more">Learn More</a> </div> </div> <div id="related-articles"> <div class="section-title"> <h4>Related Articles</h4> </div> <div class="related-article"> <h4>The Importance of Continual Improvement in Maintaining Nuclear Air Cleaning Systems</h4> <br> <a href="https://www.hsph.harvard.edu/ecpe/importance-continual-improvement-maintaining-nuclear-air-cleaning-systems/" class="related-program-learn-more">Read More</a> </div> <div class="related-article"> <h4>The Need for Maintaining Nuclear Air-Cleaning Systems Properly to Protect Public Health and Safety</h4> <br> <a href="https://www.hsph.harvard.edu/ecpe/maintaining-nuclear-air-cleaning-systems-protect-public-health-safety/" class="related-program-learn-more">Read More</a> </div> <div class="related-article"> <h4>Three Keys to Sustainable Lab Design to Improve Health and Safety</h4> <br> <a href="https://www.hsph.harvard.edu/ecpe/three-keys-sustainable-lab-design-improve-health-safety/" class="related-program-learn-more">Read More</a> </div> </div> <aside id="ecpe_ecq_widget-2" class="widget widget_ecpe_ecq_widget"><h2 class='widget-title'>Executive Core Qualifications</h2> <p class="ecq_subtext">ECQ Program Alignment Grid for U.S. Federal Government</p> <a href="https://www.hsph.harvard.edu/ecpe/ecq-training-programs/" class="action-button"> VIEW NOW </a> </aside> </div> </div> <main id="main" class="site-main" role="main"> <article id="post-2870" class="post-2870 post type-post status-publish format-standard has-post-thumbnail hentry category-environmental-health-and-safety tag-ipftw audiences-ehs-professionals audiences-government-employees"> <header class="entry-header"> <h1 class="entry-title">How Foolproof Air Cleaning Systems at Nuclear Power Plants Protect Public Health</h1> </header> <figure class="post-thumbnail wp-caption"> <img width="750" height="500" src="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg" class="attachment-post-thumbnail size-post-thumbnail wp-post-image" alt="" decoding="async" fetchpriority="high" srcset="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg 750w, https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent-150x100.jpg 150w, https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent-300x200.jpg 300w" sizes="(max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 984px) 60vw, (max-width: 1362px) 62vw, 840px" data-attachment-id="2873" data-permalink="https://www.hsph.harvard.edu/ecpe/air-cleaning-systems-nuclear-power/ipftwcontent/" data-orig-file="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg" data-orig-size="750,500" data-comments-opened="0" data-image-meta="{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"0"}" data-image-title="Nuclear Plant" data-image-description="" data-image-caption="<p>Effective air cleaning systems can make all the difference in preventing a nuclear or radiological disaster.</p> " data-medium-file="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent-300x200.jpg" data-large-file="https://www.hsph.harvard.edu/ecpe/wp-content/uploads/sites/2020/2017/06/IPFTWcontent.jpg" /><figcaption class="wp-caption-text">Effective air cleaning systems can make all the difference in preventing a nuclear or radiological disaster.</figcaption></figure> <div class="entry-content"> <p class="article-author">by Jacqueline DiChiara</p> <div class="hsph-share-buttons hsph-bootstrap"><span class="hsph-share-btns-label">Share this:</span><a rel="external noreferrer nofollow" target="_blank" href="https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F" aria-label="Facebook button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-facebook"><i class="fa fa-facebook" aria-hidden="true"></i>Facebook</a><a rel="external noreferrer nofollow" target="_blank" href="https://twitter.com/intent/tweet?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&text=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="Twitter button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-twitter"><i class="fa fa-twitter" aria-hidden="true"></i>Twitter</a><a rel="external noreferrer nofollow" target="_blank" href="https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&title=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="LinkedIn button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-linkedin"><i class="fa fa-linkedin" aria-hidden="true"></i>LinkedIn</a><a rel="external noreferrer nofollow" target="_blank" href="http://www.reddit.com/submit?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&title=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="Reddit button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-reddit"><i class="fa fa-reddit-alien" aria-hidden="true"></i>Reddit</a></span></div> <p>Air cleaning systems are often the final line of defense in the event of radiological release or nuclear disaster. The role of air cleaning systems in nuclear accidents is vital in minimizing public exposure to radioactive material and protecting public safety. When nuclear accidents occurred in the past, air cleaning systems successfully prevented disaster by mechanically filtering out particulate matter, and chemically removing gaseous radioactive material from the air, thereby mitigating technical fallout and retaining radiation. Yet, even the most advanced air cleaning systems can malfunction at any time, without warning. The ongoing implementation of rigid testing standards, filter maintenance, and stringent adherence to operational demands is necessary to keep air cleaning systems running smoothly—both during a nuclear power plant’s day-to-day operation and in a nuclear emergency.</p> <h2><strong>Air Cleaning Systems Prevent Radioactive Release</strong></h2> <p>When potentially dangerous nuclear accidents occurred in the past, radiological release was successfully prevented thanks to smoothly-operating air cleaning systems.</p> <p><a href="https://www.hsph.harvard.edu/ecpe/faculty/ronald-r-bellamy/" target="_blank" rel="noopener noreferrer">Ronald R. Bellamy, PhD</a>, Co-Program Director of the <a href="https://www.hsph.harvard.edu/ecpe/programs/in-place-filter-testing-workshop/" target="_blank" rel="noopener noreferrer"><em>In-Place Filter Testing Workshop</em></a> at the Harvard T. H. Chan School of Public Health, spent three years cleaning up <a href="https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html" target="_blank" rel="noopener noreferrer">Three Mile Island</a>—a historic nuclear power plant accident that occurred on March 28, 1979 in Pennsylvania.</p> <p>“Operators did not realize a valve was stuck open on top of the reactor vessel. Pumps that would have kept the nuclear reactor cooled were mistakenly shut off, and the reactor core partially melted,” Bellamy explains. “But safety systems at the plant operated as designed to protect public health and safety and radioactive releases into the environment were very minimal.”</p> <blockquote><p>When nuclear accidents occurred in the past, air cleaning systems successfully prevented disaster.</p></blockquote> <p>Nuclear air cleaning systems must be designed to function as intended during dire circumstances such as equipment failure or unexpected power loss, extreme weather including tornados that would drastically impact air pressure, human error, or training deficiencies—even when all backup systems malfunction, says Bellamy. “You design the plant so if something goes wrong, there’s a system that will compensate for that deficiency. You then make sure the system you designed to compensate for the deficiency has a backup system,” Bellamy states. “You design it so that second backup system has a third backup system. You may wind up with 8 different backup systems to make sure the plant can shut down safely.”</p> <p>Emphasized Bellamy, air cleaning systems must function with redundancy so that what happens to one system will not affect what happens to another. As Bellamy <a href="http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2577043" target="_blank" rel="noopener noreferrer">stated</a> last year in an article from the American Society of Mechanical Engineers, “The technical fallout, as well as the emotional response of the public, could be catastrophic. The necessity to protect public health and safety and the environment are of paramount importance, and cannot be overstated.”</p> <h2><strong>Air Cleaning System Components Ensure Protection and Safety</strong></h2> <p>Following the Three Mile Island incident, the business, design, and regulatory facets of nuclear power plants shifted to ensure adherence to rigorous regulations and criteria, says Bellamy. Nuclear power plant components are designed to minimize radioactive release to the public.</p> <p>Activated carbon is one such air cleaning system component, says Bellamy. “Activated carbon removes gaseous material before it is released in the plants—primarily radioactive iodine,” he explains. “Significant amounts of iodine 131 may cause thyroid cancer. So the activated carbon does a similar job for the iodine as high efficiency particulate absolute (HEPA) filters do for particulate material.”</p> <blockquote><p>Following the Three Mile Island incident, the business, design, and regulatory facets of nuclear power plants shifted to ensure adherence to rigorous regulations and criteria.</p></blockquote> <p>Bellamy says there is little need to be concerned about radioactive iodine exposure from the operation of a nuclear power plant, since we are all exposed to radiation every day. “Bananas, for example, are very rich in Potassium-40, a radioactive material known to set off radiation detectors at airports,” he adds. A person in a normal year averages about 600 millirem—the unit of measurement used for absorbed radiation dose, says Bellamy. “The calculated doses from exposure due to radiation released from a nuclear power plant for an individual are around 2 to 5 millirem—a very small fraction of 600,” he says.</p> <p>Another component of air cleaning systems designed to meet rigid standards are the HEPA filters that remove particulate material. “Each filter is tested independently at the manufacturer before they are allowed to ship it to a facility for use,” says Bellamy. “The filters are required in this laboratory test to remove at least 99.97% of particulate material.”</p> <p>Regulatory authorities use the air cleaning systems in helping to predict what the radioactive material available for release after an accident might be—referred to as a radioactive source term, says Bellamy. “You can define how much material the radioactive source term is that might be released to the public. You then take that radioactive source term and apply the efficiency of the filter so you can calculate how much radioactive material actually is released from the plant,” he states.</p> <p>“You can take the source term and reduce it by the efficiency of the filters. You can look at meteorology and use health physics factors to calculate the doses. The doses allowed to members of the public are required to be small fractions of the radioactive exposure an individual would get normally,” states Bellamy. “Even in a nuclear incident, the public would be adequately protected,” he emphasizes.</p> <h2><strong>Air Cleaning System Regulations Increase Protection, Right Down to the Nanoscale</strong></h2> <p>Ensuring greater protection of public health and safety means continuously meeting evolving industry regulation standards. According to <a href="https://www.hsph.harvard.edu/ecpe/faculty/john-m-price/" target="_blank" rel="noopener noreferrer">John M. Price</a>, PhD, CIH, CSP, PE, Co-Program Director of the <a href="https://www.hsph.harvard.edu/ecpe/programs/in-place-filter-testing-workshop/" target="_blank" rel="noopener noreferrer"><em>In-Place Filter Testing Workshop</em></a> at the Harvard Chan School and Director of Environmental Health and Safety at Northeastern University, strict ongoing controls are implemented to ensure successful contamination control across greater health and healthcare industries, such as clean room technology, micro-manufacturing, and pharmaceuticals.</p> <blockquote><p>It is critical that systems are tested periodically, equipment is properly maintained, and the integrity of filters is intact on a day-to-day basis.</p></blockquote> <p>One such regulation involves the labor-intensive process of changing out filters. “Filters used for emergency systems tend to stay in place for a long time. But when you’re not using them, they may degrade over time,” Price explains. “At clean rooms within the biotech industry, they’re probably changing the filters if not on an annual basis, probably within a few years. Typically, this is the last stage of filtration. And they have pre-filters to remove a lot of the larger-sized particles so they don’t end up clogging HEPA filters,” Price says.</p> <p>It is critical that systems are tested periodically, equipment is properly maintained, and the integrity of filters is intact on a day-to-day basis, Price states. One critical filter testing component is contamination control. “There was an issue a few years ago with drug compounding where drugs were to be used intravenously, but they weren’t done in clean environments. Several people died from contaminated drugs,” states Price. “Research and manufacturing processes are highly dependent on a clean environment. These environments typically have different ratings regarding how they measure toxic contamination and airborne particulate matter that interferes with their processes since they’re going down to the nanoscale,” he adds.</p> <h2><strong>Global Standards and the Greater Future of Nuclear Power</strong></h2> <p>Bellamy says the 500 nuclear power plants worldwide rely on the evolution of global air cleaning regulatory standards. Global standards and codes may be different compared to the United States, but they are likely just as stringent, adds Price. “The basic methodology, principles, and theory of air flow measurements and filter testing is not different anywhere else in the world,” Price says. “Although we do have American national standards with the American Society of Testing and Manufacturing, they recognize there are international, European standards. They want to harmonize a lot of that criteria.”</p> <p>“Domestically speaking, nuclear power is responsible for a sizable part of the country’s electricity. One hundred operating plants in the United States provide nearly 20 percent of the nation’s electricity,” Bellamy says. “The future of nuclear power is probably brighter overseas than it is in the United States now, but that 20 percent of the electricity needs to come from somewhere,” he stresses. Here in the United States, the federal government has long advocated for air cleaning guides and standards to be published and converted into legally binding international codes and standards. For example, the international ASME AG-1 Code document, “Code on Nuclear Air and Gas Treatment,” as Bellamy noted in his article, took hundreds of nuclear air cleaning experts 40 years to complete. Bellamy is the Chair of the ASME Committee responsible for the AG-1 Code, and notes that their work is continuing.</p> <p>The manufacturing of filters and other system equipment will continue to drive the international market, Price predicts. “Manufacturers have a global market and they’re very interested to make sure not only do we meet American standards, but we meet European or international standards.”</p> <p>Criteria is becoming much more stringent as demand for cost-effective technology rises, he adds. “The filter manufacturers are constantly looking at new applications for technology and trying to enhance the materials they work with to make the filters,” Price says. “It’s cutting-edge because we’re trying to remove the smallest of particles,” he stresses.</p> <p>Air cleaning systems are perhaps the last ray of hope for the human race when radiological release or nuclear catastrophe strikes. That being said, the popular belief that nuclear power plants themselves are dangerous is invalid, says Bellamy, who has lived with his family in close proximity to power plants. “The risk of dying from a nuclear power plant is equivalent to the risk of being hit by a meteor,” he says. “So if you’re not worried about being hit by a meteor tonight, don’t be worried about dying from a nuclear power plant tonight.”</p> <hr /> <p>Harvard T.H. Chan School of Public Health offers the <a href="https://www.hsph.harvard.edu/ecpe/programs/in-place-filter-testing-workshop/" target="_blank" rel="noopener noreferrer"><em>In-Place Filter Testing Workshop</em></a>, which focuses on testing and certifying systems containing HEPA filtration and gas adsorption systems for nuclear and non-nuclear applications.</p> </div> <footer class="entry-footer"> <div class="hsph-share-buttons hsph-bootstrap"><span class="hsph-share-btns-label">Share this:</span><a rel="external noreferrer nofollow" target="_blank" href="https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F" aria-label="Facebook button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-facebook"><i class="fa fa-facebook" aria-hidden="true"></i>Facebook</a><a rel="external noreferrer nofollow" target="_blank" href="https://twitter.com/intent/tweet?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&text=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="Twitter button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-twitter"><i class="fa fa-twitter" aria-hidden="true"></i>Twitter</a><a rel="external noreferrer nofollow" target="_blank" href="https://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&title=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="LinkedIn button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-linkedin"><i class="fa fa-linkedin" aria-hidden="true"></i>LinkedIn</a><a rel="external noreferrer nofollow" target="_blank" href="http://www.reddit.com/submit?url=https%3A%2F%2Fwww.hsph.harvard.edu%2Fecpe%2Fair-cleaning-systems-nuclear-power%2F&title=How+Foolproof+Air+Cleaning+Systems+at+Nuclear+Power+Plants+Protect+Public+Health" aria-label="Reddit button link" class="btn btn-light btn-sm btn-squared shadow-none mr-2 mb-2 hsph-share-button-reddit"><i class="fa fa-reddit-alien" aria-hidden="true"></i>Reddit</a></span></div> <span class="posted-on"> <span class="screen-reader-text">Posted on</span> <a href="https://www.hsph.harvard.edu/ecpe/air-cleaning-systems-nuclear-power/" rel="bookmark"> <time class="entry-date" datetime="2017-06-14T09:17:09-04:00">June 14, 2017</time> <time class="updated" datetime="2023-10-03T11:21:53-04:00" hidden>October 3, 2023</time> </a> </span> <span class="cat-links"><span class="screen-reader-text">Categories </span><a href="https://www.hsph.harvard.edu/ecpe/category/environmental-health-and-safety/" rel="category tag">Occupational, Environmental Health, and Safety</a></span><span class="tags-links"><span class="screen-reader-text">Tags </span><a href="https://www.hsph.harvard.edu/ecpe/tag/ipftw/" rel="tag">ipftw</a></span> </footer> </article> <nav class="navigation post-navigation" aria-label="Posts"> <h2 class="screen-reader-text">Post navigation</h2> <div class="nav-links"><div class="nav-previous"><a href="https://www.hsph.harvard.edu/ecpe/communications-strategy-radiological-nuclear-accident/" rel="prev"><span class="meta-nav" aria-hidden="true">Previous</span> <span class="screen-reader-text">Previous post:</span> <span class="post-title">The Need for a Strong Communications Strategy in the Face of a Radiological or Nuclear Accident</span></a></div><div class="nav-next"><a href="https://www.hsph.harvard.edu/ecpe/value-of-health-outcomes-research/" rel="next"><span class="meta-nav" aria-hidden="true">Next</span> <span class="screen-reader-text">Next post:</span> <span class="post-title">The Value of Applying Health Outcomes Research to Improve Treatment Results</span></a></div></div> </nav> </main> <aside id="secondary" class="sidebar widget-area" role="complementary"> <section id="custom_html-3" class="widget_text widget widget_custom_html"><h2 class="widget-title">Inside Health</h2><div class="textwidget custom-html-widget"><iframe src="https://proxy.qualtrics.com/proxy/?url=https%3A%2F%2Fexeced2.sph.harvard.edu%2Fl%2F962443%2F2023-05-12%2F4ympt&token=jqLnqJfVHClg0Sk69vRdWwKEZAm45fhqaRmeJ7fA3Cg%3D" width="100%" height="500" type="text/html" frameborder="0" allowtransparency="true" style="border: 0"></iframe></div></section> </aside> </div> </div> <footer id="colophon" class="site-footer" role="contentinfo"> <div id="footer-audience-menu" class="footer-audience-menu"> <span class="footer-information-for">Information For:</span> <nav id="footer-audience-navigation" class="footer-audience-navigation" role="navigation" aria-label="Audience Menu"> <div class="menu-audience-menu-container"><ul id="menu-audience-menu-1" class="hsph-audience-menu"><li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-253"><a href="/ecpe/audiences/clinicians/">Clinicians</a></li> <li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-254"><a href="/ecpe/audiences/ehs-professionals/">EHS Professionals</a></li> <li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-255"><a href="/ecpe/audiences/academics/">Academics</a></li> <li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-256"><a href="/ecpe/audiences/executives/">Executives</a></li> <li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-257"><a href="/ecpe/audiences/government-employees/">Gov Employees</a></li> <li class="menu-item menu-item-type-custom menu-item-object-custom menu-item-258"><a href="/ecpe/programs/">More</a></li> </ul></div> </nav> </div> <div class="site-info"> <div class="site-footer-logo"><a href="https://www.hsph.harvard.edu/">Harvard T.H. Chan School of Public Health</a></div> <div class="site-footer-org"><a href="https://www.hsph.harvard.edu/ecpe/" rel="home">Executive and Continuing Education</a></div> <address class="vcard"> <div class="adr"> <span class="street-address">677 Huntington Avenue</span> <span class="locality">Boston</span>, <abbr class="region" title="Massachusetts">MA</abbr> <span class="postal-code">02115</span> </div> <div class="tel"><a href="tel:6174322100"> 617-432-2100 </a></div> <div class="email"><a href="mailto:contedu@hsph.harvard.edu">contedu@hsph.harvard.edu</a></div> </address> </div> <div id="footer-social-menu" class="footer-social-menu"> <nav id="footer-social-navigation" class="footer-social-navigation" role="navigation" aria-label="Primary Menu"> <div class="menu-footer-social-media-container"><ul id="menu-footer-social-media" class="social-navigation"><li id="menu-item-50" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-50"><a href="https://www.linkedin.com/company/harvard-school-of-public-health-executive-and-continuing-professional-education">LinkedIn</a></li> <li id="menu-item-49" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-49"><a href="https://www.facebook.com/HarvardChanECPE">Facebook</a></li> <li id="menu-item-48" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-48"><a href="https://twitter.com/HarvardChanECPE">Twitter</a></li> </ul></div> </nav> </div> <div id="footer-footer-menu" class="footer-footer-menu"> <nav id="footer-navigation" class="footer-navigation" role="navigation" aria-label="Primary Menu"> <div class="menu-footer-links-container"><ul id="menu-footer-links" class="hsph-footer-menu"><li id="menu-item-37" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-37"><a href="https://www.hsph.harvard.edu">Harvard Chan Home</a></li> <li id="menu-item-38" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-38"><a href="http://www.harvard.edu">Harvard University Home</a></li> <li id="menu-item-39" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-39"><a href="https://www.hsph.harvard.edu/privacy-policy/">Privacy Policy</a></li> <li id="menu-item-40" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-40"><a href="http://www.harvard.edu/copyright-issue">Report Copyright Violation</a></li> <li id="menu-item-4544" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-4544"><a href="https://accessibility.harvard.edu/">Accessibility</a></li> <li id="menu-item-25163" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-25163"><a href="https://accessibility.huit.harvard.edu/digital-accessibility-policy">Digital Accessibility</a></li> </ul></div> </nav> </div> <div id="copyright" class="copyright"> Copyright © 2024 The President and Fellows of Harvard College </div> </footer> </div> </div> <div class="menu-mask"></div>  <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XL6K" height="0" width="0" title="Google tag manager" aria-hidden="true" style="display:none;visibility:hidden"></iframe></noscript>  <script> // Slide controls for the sub brand carousel template jQuery(document).ready(function($) { if ( $('#sidebar-carousel-widget .flexslider').length && $().flexslider ) { $('#sidebar-carousel-widget .flexslider').flexslider({ animation: 'fade', prevText: ' ', nextText: ' ', controlsContainer: '#hsph-carousel-widget-controls', }); } }); </script> <script> // Slide controls for the sub brand carousel template jQuery(document).ready(function($) { if ( $('#news-sidebar-carousel-widget .flexslider').length && $().flexslider ) { $('#news-sidebar-carousel-widget .flexslider').flexslider({ animation: 'fade', prevText: ' ', nextText: ' ', controlsContainer: '#hsph-news-carousel-widget-controls', }); } }); </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-tagging/assets/js/hsph-plugin-tagging.js?ver=1.1.5" id="hsph-plugin-tagging-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-tinymce-tweaks/assets/js/jquery.tablesorter.min.js?ver=2.31.1" id="jquery-tablesorter-js-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-tinymce-tweaks/assets/js/hsph-table-sortable.js?ver=1.1.1" id="hsph-table-sortable-js-js"></script> <script type="text/javascript" id="ecpe_public-js-extra"> /* <![CDATA[ */ var ecpe = {"faculty_directory":"","is_program_page":"","program_finder":"","program_prefix":null,"taxonomy":"","term":""}; /* ]]> */ </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-ecpe/public/js/ecpe-public.js?ver=2.0.2" id="ecpe_public-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-includes/js/jquery/ui/datepicker.min.js?ver=1.13.3" id="jquery-ui-datepicker-js"></script> <script type="text/javascript" id="jquery-ui-datepicker-js-after"> /* <![CDATA[ */ jQuery(function(jQuery){jQuery.datepicker.setDefaults({"closeText":"Close","currentText":"Today","monthNames":["January","February","March","April","May","June","July","August","September","October","November","December"],"monthNamesShort":["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"],"nextText":"Next","prevText":"Previous","dayNames":["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"],"dayNamesShort":["Sun","Mon","Tue","Wed","Thu","Fri","Sat"],"dayNamesMin":["S","M","T","W","T","F","S"],"dateFormat":"MM d, yy","firstDay":0,"isRTL":false});}); /* ]]> */ </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/js/skip-link-focus-fix.js?ver=1.3.101" id="hsph-skip-link-focus-fix-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/js/jquery.flexslider-min.js?ver=1.3.101" id="jquery-flexslider-js"></script> <script type="text/javascript" id="hsph-script-js-extra"> /* <![CDATA[ */ var screenReaderText = {"expand":"<span class=\"screen-reader-text\">expand child menu<\/span>","collapse":"<span class=\"screen-reader-text\">collapse child menu<\/span>"}; /* ]]> */ </script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/themes/theme-main-2016/assets/js/functions.js?ver=1.3.101" id="hsph-script-js"></script> <script type="text/javascript" src="https://www.hsph.harvard.edu/ecpe/wp-content/plugins/plugin-design-system/assets/js/hsph-bootstrap.bundle.min.js?ver=1.4.12" id="hsph-bootstrap-js"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"NRJS-26d49e9cd1d82010791","applicationID":"529647296","transactionName":"YlBRN0pRWBUDBU1dWFsacgBMWVkITRVQWlBZUA==","queueTime":0,"applicationTime":360,"atts":"ThdSQQJLSxs=","errorBeacon":"bam.nr-data.net","agent":""}</script></body> </html>