pm2. 5衡量標(biāo)準(zhǔn)

mmsy5201314 2017-09-16 01:58:13 584 瀏覽

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socool薇 2017-09-16 12:57:40

pm2. 5，即細(xì)顆粒物的標(biāo)準(zhǔn)，是由美國(guó)在1997年提出的，主要是為了更有效地監(jiān)測(cè)隨著工業(yè)化日益發(fā)達(dá)而出現(xiàn)的、在舊標(biāo)準(zhǔn)中被忽略的對(duì)人體有害的細(xì)小顆粒物。細(xì)顆粒物指數(shù)已經(jīng)成為一個(gè)重要的測(cè)控空氣污染程度的指數(shù)。目前，我國(guó)的pm2.5標(biāo)準(zhǔn)值為24小時(shí)平均濃度小于75微克/立方米為達(dá)標(biāo)，然而，這一數(shù)值與pm2.5國(guó)際標(biāo)準(zhǔn)相比，還相差甚遠(yuǎn)，僅僅是達(dá)到世衛(wèi)組織設(shè)定的Z寬標(biāo)準(zhǔn)。世界衛(wèi)生組織(WHO)認(rèn)為，pm2.5標(biāo)準(zhǔn)值為小于每立方米10微克。年均濃度達(dá)到每立方米35微克時(shí)，人患病并致死的幾率將大大增加。而以世衛(wèi)組織數(shù)據(jù)為準(zhǔn)的話，pm2.5國(guó)際標(biāo)準(zhǔn)分別為準(zhǔn)則值，24小時(shí)小于25微克;過(guò)渡期目標(biāo)1，24小時(shí)小于75微克;過(guò)度目標(biāo)2，24小時(shí)小于50微克;過(guò)度其目標(biāo)3，24小時(shí)小于37.5微克。

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