Lub Koom Haum Saib Xyuas Kev Noj Qab Haus Huv Ntiaj Teb (WHO) tau tshaj tawm tsab ntawv tshaj tawm lub lim tiam dhau los hais tias ntau dua 1 lab tus neeg tuag los ntawm mob ntsws, mob hawb pob, mob ntsws cancer thiab lwm yam kab mob ua pa tuaj yeem tiv thaiv thoob ntiaj teb txhua xyoo yog tias cov teb chaws tau ntsuas los txhim kho huab cua zoo. Qhov no yog lub ntiaj teb lub cev thawj qhov kev tshawb fawb loj ntawm huab cua sab nraum zoov los ntawm thoob plaws ntiaj teb.
Thaum Asmeskas huab cua tsis zoo piv rau cov uas pom hauv cov tebchaws xws li Iran, Is Nrias teb, thiab Pakistan, tsis muaj kev lom zem me ntsis thaum saib cov txheeb cais rau California.
Qhov kev tshawb fawb no tso siab rau cov ntaub ntawv tshaj tawm hauv lub tebchaws nyob rau ntau xyoo dhau los, thiab ntsuas cov theem ntawm cov pa hauv huab cua me dua 10 micrometers - hu ua PM10s - rau yuav luag 1,100 lub nroog. LEEJ TWG kuj tau tshaj tawm cov lus luv luv piv rau qib ntawm cov hmoov av zoo dua, hu ua PM2.5s.
LEEJ TWG pom zoo kom muaj kev txwv siab tshaj ntawm 20 micrograms ib lub cubic meter rau PM10s (piv txwv li "ib xyoos ib zaug" hauv WHO tsab ntawv ceeb toom), uas tuaj yeem ua rau muaj teeb meem ua pa hnyav rau tib neeg. Ntau tshaj 10 micrograms ib cubic meter ntawm PM2.5s yog suav tias yog teeb meem rau tib neeg.
Topping cov npe ntawm cov nroog phem tshaj plaws hauv lub tebchaws kom muaj kev cuam tshuam ntau ntxiv rau ob qhov kev faib tawm ntawm cov teeb meem yog Bakersfield, uas tau txais txhua xyoo txhais tau tias ntawm 38ug / m3 rau PM10s, thiab 22.5ug / m3 rau PM2.5s. Fresno tsis deb tom qab, qhov chaw thib 2 thoob tebchaws, nrog Riverside / San Bernardino thov qhov chaw thib 3 hauv Asmeskas daim ntawv teev npe. Zuag qhia tag nrho, California lub nroog tau thov 11 ntawm 20 tus neeg ua txhaum loj tshaj plaws nyob rau hauv ob pawg, tag nrho cov no tau dhau los ntawm WHO kev nyab xeeb.
"Peb tuaj yeem tiv thaiv cov neeg tuag ntawd," said Dr. Maria Neira, tus thawj coj ntawm WHO lub chaw saib xyuas kev noj qab haus huv thiab ib puag ncig, uas sau tseg txog kev nqis peev rau cov pa phem qis sai sai vim tias cov kab mob qis dua thiab, yog li ntawd, txo nqi kho mob.
Tau ntau xyoo, cov kws tshawb fawb thoob ntiaj teb tau txuas ntxiv txo cov teeb meem me me rau cov hav zoov noj qab haus huv hauv nroog. Kev tshawb fawb los ntawm Natural Environments Research Council hauv 2007 qhia tias PM10 txo qis ntawm 7%-20% tuaj yeem ua tiav yog tias cog ntoo ntau, nyob ntawm seb muaj cov chaw cog qoob loo. Hauv Tebchaws Meskas, Lub Tsev Haujlwm Saib Xyuas Kev Tshawb Fawb Hauv Nroog tau luam tawm ib daim ntawv hauv xyoo 2006 uas sau tseg Sacramento 748 lab ntoo lim 10 tons ntawm PMXNUMX txhua xyoo.