Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
J Expo Sci Environ Epidemiol. 2024 Sep;34(5):836-844. doi: 10.1038/s41370-023-00623-0. Epub 2023 Dec 18.
Improved understanding of sources and processes that drive exposure contrast of fine particulate matter (PM) is essential for designing and interpreting epidemiological study outcomes.
We investigate the contribution of various sources and processes to PM exposure contrasts at different spatial scales across the continental United States.
We consider three cases: exposure contrast within a metro area, nationwide exposure contrast with high spatial resolution, and nationwide exposure contrast with low spatial resolution. Using national empirical model estimates of source- and chemically specific PM concentration predictions, we quantified the contribution of various sources and processes to PM exposure contrasts in these three cases.
At the metro level (i.e., metropolitan statistical area; MSA), exposure contrasts of PM vary between -1.8 to 1.4 µg m relative to the MSA-mean with about 50% of within-MSA exposure contrast of PM caused by cooking and mobile source primary PM. For the national exposure contrast at low-resolution (i.e., using MSA-average mean concentrations), exposure contrasts (relative to the national mean: -3.9 to 3.2 µg m) are larger than within an MSA with ~80% of the variation due to secondary PM. National exposure contrast at high resolution (census block) has the largest absolute range (relative to the national mean: -4.7 to 3.7 µg m) due to both regional and intra-urban contributions; on average, 65% of the national exposure contrast is due to secondary PM with the remaining from the primary PM (cooking and mobile source 26%, other 9%).
Our study provides a comprehensive analysis of the sources and processes that contribute to exposure contrasts of PM across different geographic areas in the US. For the first time on a national scale, we used high spatial resolution source-specific exposure estimates to identify the primary contributors to PM exposure contrasts. The study also highlights the advantages of different study designs for investigating the health impacts of specific PM components. The findings provide novel insights that can inform public health policies aimed at reducing PM exposure and advance the understanding of the epidemiological study outcomes.
深入了解导致细颗粒物（PM）暴露对比的来源和过程，对于设计和解释流行病学研究结果至关重要。
我们研究了在美国不同空间尺度下，各种来源和过程对 PM 暴露对比的贡献。
我们考虑了三种情况：都市区内的暴露对比、具有高空间分辨率的全国性暴露对比和具有低空间分辨率的全国性暴露对比。利用国家经验模型对源和化学特定 PM 浓度预测的估计，我们量化了在这三种情况下各种来源和过程对 PM 暴露对比的贡献。
在都市区（即大都市统计区；MSA）一级，PM 的暴露对比在 -1.8 至 1.4μg/m 之间变化，与 MSA 平均值相比，约 50%的 PM 内 MSA 暴露对比是由烹饪和移动源一次 PM 造成的。对于低分辨率的全国性暴露对比（即使用 MSA 平均浓度），暴露对比（相对于全国平均值：-3.9 至 3.2μg/m）大于 MSA 内部，其中约 80%的变化是由二次 PM 造成的。高分辨率（普查块）的全国性暴露对比具有最大的绝对范围（相对于全国平均值：-4.7 至 3.7μg/m），这是由于区域和城市内部的贡献；平均而言，65%的全国性暴露对比归因于二次 PM，其余的来自一次 PM（烹饪和移动源 26%，其他 9%）。
我们的研究提供了对美国不同地理区域内 PM 暴露对比的来源和过程的全面分析。我们首次在全国范围内使用高空间分辨率的源特定暴露估计来确定 PM 暴露对比的主要贡献者。该研究还突出了不同研究设计在研究特定 PM 成分对健康影响方面的优势。研究结果提供了新的见解，可以为旨在减少 PM 暴露和推进对流行病学研究结果的理解的公共卫生政策提供信息。
