School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA.
Environ Health Perspect. 2012 Dec;120(12):1699-704. doi: 10.1289/ehp.1205201. Epub 2012 Aug 10.
Growing evidence indicates that toxicity of fine particulate matter ≤ 2.5 μm in diameter (PM2.5) differs by chemical component. Exposure to components may differ by population.
We investigated whether exposures to PM2.5 components differ by race/ethnicity, age, and socioeconomic status (SES).
Long-term exposures (2000 through 2006) were estimated for 215 U.S. census tracts for PM2.5 and for 14 PM2.5 components. Population-weighted exposures were combined to generate overall estimated exposures by race/ethnicity, education, poverty status, employment, age, and earnings. We compared population characteristics for tracts with and without PM2.5 component monitors.
Larger disparities in estimated exposures were observed for components than for PM2.5 total mass. For race/ethnicity, whites generally had the lowest exposures. Non-Hispanic blacks had higher exposures than did whites for 13 of the 14 components. Hispanics generally had the highest exposures (e.g., 152% higher than whites for chlorine, 94% higher for aluminum). Young persons (0-19 years of age) had levels as high as or higher than other ages for all exposures except sulfate. Persons with lower SES had higher estimated exposures, with some exceptions. For example, a 10% increase in the proportion unemployed was associated with a 20.0% increase in vanadium and an 18.3% increase in elemental carbon. Census tracts with monitors had more non-Hispanic blacks, lower education and earnings, and higher unemployment and poverty than did tracts without monitors.
Exposures to PM2.5 components differed by race/ethnicity, age, and SES. If some components are more toxic than others, certain populations are likely to suffer higher health burdens. Demographics differed between populations covered and not covered by monitors.
越来越多的证据表明，直径≤2.5μm 的细颗粒物（PM2.5）的毒性因化学组分而异。不同人群的暴露情况可能有所不同。
我们研究了 PM2.5 组分的暴露情况是否因种族/族裔、年龄和社会经济地位（SES）而异。
我们估计了 215 个美国普查区在 2000 年至 2006 年期间的 PM2.5 和 14 种 PM2.5 组分的长期暴露情况。通过人口加权来合并暴露量，以生成按种族/族裔、教育程度、贫困状况、就业、年龄和收入划分的总体估计暴露量。我们比较了有和没有 PM2.5 组分监测器的普查区的人口特征。
与 PM2.5 总质量相比，组分的估计暴露量差异更大。在种族/族裔方面，白人的暴露量通常最低。与白人相比，非西班牙裔黑人的 14 种组分中有 13 种的暴露量更高。西班牙裔的暴露量通常最高（例如，氯的暴露量比白人高 152%，铝的暴露量比白人高 94%）。除硫酸盐外，所有年龄段的年轻人（0-19 岁）的暴露水平都与其他年龄段一样高或更高。社会经济地位较低的人估计暴露量较高，但也有一些例外。例如，失业比例增加 10%，与钒增加 20.0%和元素碳增加 18.3%有关。与没有监测器的普查区相比，有监测器的普查区的非西班牙裔黑人比例更高，教育程度和收入水平更低，失业率和贫困率更高。
PM2.5 组分的暴露情况因种族/族裔、年龄和 SES 而异。如果某些组分比其他组分更具毒性，那么某些人群可能会承受更高的健康负担。监测覆盖人群和未覆盖人群的人口特征存在差异。
