New Insights for Tracking Global and Local Trends in Exposure to Air Pollutants

Over six million
people die prematurely each year from exposure
to air pollution. Current air quality metrics insufficiently monitor
exposure to air pollutants. This gap hinders the ability of decisionmakers
to address the public health impacts of air pollution. To spur new
emissions control policies and ensure implemented solutions realize
meaningful gains in environmental health, we develop a framework of
public-health-focused air quality indicators that quantifies over
200 countries’ trends in exposure to particulate matter, ozone,
nitrogen oxides, sulfur dioxide, carbon monoxide, and volatile organic
compounds. We couple population density to ground-level pollutant
concentrations to derive population-weighted exposure metrics that
quantify the pollutant levels experienced by the average resident
in each country. Our analyses demonstrate that most residents in 171
countries experience pollutant levels exceeding international health
guidelines. In addition, we find a negative correlation between temporal
trends in ozone and nitrogen oxide concentrations, whichwhen
qualitatively interpreted with a simple atmospheric chemistry box
modelcan help describe the apparent tradeoff between the mitigation
of these two pollutants on local scales. These novel indicators and
their applications enable regulators to identify their most critical
pollutant exposure trends and allow countries to track the performance
of their emission control policies over time.

每年因暴露于空气污染而导致六百万人过早死亡。当前空气质量指标不足以监测对空气污染物的暴露。这一差距阻碍了决策者应对空气污染对公共健康影响的应对能力。为了推动新的排放控制政策，并确保实施的解决方案在环境健康方面实现实质性收益，我们开发了一套以公共卫生为导向的空气质量指标框架，该框架量化了200多个国家在颗粒物、臭氧、氮氧化物、二氧化硫、一氧化碳和挥发性有机化合物等方面的暴露趋势。我们将人口密度与地面污染物浓度相结合，推导出以人口权重为单位的暴露指标，这些指标量化了每个国家普通居民所经历的污染物水平。我们的分析表明，171个国家的居民中，大多数人的污染物水平超过了国际健康指南。此外，我们还发现臭氧和氮氧化物浓度的时间趋势之间存在负相关关系，这一关系通过简单的大气化学箱模型进行定性解释时，有助于描述这两种污染物在局部尺度上减轻的明显权衡。这些新颖的指标及其应用使监管者能够识别其最关键的污染物暴露趋势，并允许各国跟踪其排放控制政策随时间的执行表现。