Estimating the National Public Health Burden Associated with Exposure to Ambient PM_2.5 and Ozone

TLDR

Ground‑level ozone and fine particulate matter are linked to increased mortality risk. The study quantifies the health burden of modeled 2005 O3 and PM2.5 concentrations across the United States. By fusing CMAQ model outputs with monitored data to generate 12‑km grid surfaces of summer 8‑hour O3 and annual PM2.5, and combining these with spatially resolved demographic information, the authors estimate mortality, life‑year loss, and avoided deaths by pollutant, age group, and region. The analysis estimates 130,000 PM2.5‑related deaths and 4,700 ozone‑related deaths in 2005, nearly 1.1 million life years lost for ages 65‑99 from PM2.5 and ~36,000 from ozone, and shows that despite recent air‑quality improvements, current levels still pose a nontrivial public‑health risk.

Abstract

Ground-level ozone (O(3)) and fine particulate matter (PM(2.5)) are associated with increased risk of mortality. We quantify the burden of modeled 2005 concentrations of O(3) and PM(2.5) on health in the United States. We use the photochemical Community Multiscale Air Quality (CMAQ) model in conjunction with ambient monitored data to create fused surfaces of summer season average 8-hour ozone and annual mean PM(2.5) levels at a 12 km grid resolution across the continental United States. Employing spatially resolved demographic and concentration data, we assess the spatial and age distribution of air-pollution-related mortality and morbidity. For both PM(2.5) and O(3) we also estimate: the percentage of total deaths due to each pollutant; the reduction in life years and life expectancy; and the deaths avoided according to hypothetical air quality improvements. Using PM(2.5) and O(3) mortality risk coefficients drawn from the long-term American Cancer Society (ACS) cohort study and National Mortality and Morbidity Air Pollution Study (NMMAPS), respectively, we estimate 130,000 PM(2.5) -related deaths and 4,700 ozone-related deaths to result from 2005 air quality levels. Among populations aged 65-99, we estimate nearly 1.1 million life years lost from PM(2.5) exposure and approximately 36,000 life years lost from ozone exposure. Among the 10 most populous counties, the percentage of deaths attributable to PM(2.5) and ozone ranges from 3.5% in San Jose to 10% in Los Angeles. These results show that despite significant improvements in air quality in recent decades, recent levels of PM(2.5) and ozone still pose a nontrivial risk to public health.