Dataset Information

Long-term exposure to PM_2.5 major components and mortality in the southeastern United States.

ABSTRACT:

Background

Long-term exposure to fine particulate matter (PM_2.5) mass has been associated with adverse health effects. However, the health effects of PM_2.5 components have been less studied. There is a pressing need to better understand the relative contribution of components of PM_2.5, which can lay the scientific basis for designing effective policies and targeted interventions.

Methods

We conducted a population-based cohort study, comprising all Medicare enrollees aged 65 or older in the southeastern United States from 2000 to 2016, to explore the associations between long-term exposure to PM_2.5 major components and all-cause mortality among the elderly. Based on well-validated prediction models, we estimated ZIP code-level annual mean concentrations for five major PM_2.5 components, including black carbon (BC), nitrate (NIT), organic matter (OM), sulfate (SO₄), and soil particles. Data were analyzed using Cox proportional hazards models, adjusting for potential confounders.

Results

The cohort comprised 13,590,387 Medicare enrollees and a total of 107,191,652 person-years. In single-component models, all five major PM_2.5 components were significantly associated with elevated all-cause mortality. The hazard ratios (HR) per interquartile range (IQR) increase in exposure were 1.027 (95% CI: 1.025-1.030), 1.012 (95% CI: 1.010-1.013), 1.018 (95% CI: 1.017-1.020), 1.021 (95% CI: 1.017-1.024), and 1.004 (95% CI: 1.003-1.006) for BC, NIT, OM, SO₄, and soil particles, respectively. While the effect estimate of soil component was statistically significant, it is much smaller than those of combustion-related components.

Conclusion

Our study provides epidemiological evidence that long-term exposure to major PM_2.5 components is significantly associated with elevated mortality.

SUBMITTER: Wang Y

PROVIDER: S-EPMC9190768 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Long-term exposure to PM<sub>2.5</sub> major components and mortality in the southeastern United States.

Wang Yifan Y Xiao Siyao S Zhang Yuhan Y Chang Howard H Martin Randall V RV Van Donkelaar Aaron A Gaskins Audrey A Liu Yang Y Liu Pengfei P Shi Liuhua L

Environment international 20211104

<h4>Background</h4>Long-term exposure to fine particulate matter (PM<sub>2.5</sub>) mass has been associated with adverse health effects. However, the health effects of PM<sub>2.5</sub> components have been less studied. There is a pressing need to better understand the relative contribution of components of PM<sub>2.5</sub>, which can lay the scientific basis for designing effective policies and targeted interventions.<h4>Methods</h4>We conducted a population-based cohort study, comprising all ...[more]

PMID: 34741960

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Project description:It has been posited that populations being exposed to long-term air pollution are more susceptible to COVID-19. Evidence is emerging that long-term exposure to ambient PM2.5 (particulate matter with aerodynamic diameter 2.5 μm or less) associates with higher COVID-19 mortality rates, but whether it also associates with the speed at which the disease is capable of spreading in a population is unknown. Here, we establish the association between long-term exposure to ambient PM2.5 in the United States (US) and COVID-19 basic reproduction ratio R0- a dimensionless epidemic measure of the rapidity of disease spread through a population. We inferred state-level R0 values using a state-of-the-art susceptible, exposed, infected, and recovered (SEIR) model initialized with COVID-19 epidemiological data corresponding to the period March 2-April 30. This period was characterized by a rapid surge in COVID-19 cases across the US states, implementation of strict social distancing measures, and a significant drop in outdoor air pollution. We find that an increase of 1 μg/m3 in PM2.5 levels below current national ambient air quality standards associates with an increase of 0.25 in R0 (95% CI: 0.048-0.447). A 10% increase in secondary inorganic composition, sulfate-nitrate-ammonium, in PM2.5 associates with ≈10% increase in R0 by 0.22 (95% CI: 0.083-0.352), and presence of black carbon (soot) in the ambient environment moderates this relationship. We considered several potential confounding factors in our analysis, including gaseous air pollutants and socio-economical and meteorological conditions. Our results underscore two policy implications - first, regulatory standards need to be better guided by exploring the concentration-response relationships near the lower end of the PM2.5 air quality distribution; and second, pollution regulations need to be continually enforced for combustion emissions that largely determine secondary inorganic aerosol formation.

Project description:BackgroundImproved understanding of sources and processes that drive exposure contrast of fine particulate matter (PM2.5) is essential for designing and interpreting epidemiological study outcomes.ObjectiveWe investigate the contribution of various sources and processes to PM2.5 exposure contrasts at different spatial scales across the continental United States.MethodsWe 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 PM2.5 concentration predictions, we quantified the contribution of various sources and processes to PM2.5 exposure contrasts in these three cases.ResultsAt the metro level (i.e., metropolitan statistical area; MSA), exposure contrasts of PM2.5 vary between -1.8 to 1.4 µg m-3 relative to the MSA-mean with about 50% of within-MSA exposure contrast of PM2.5 caused by cooking and mobile source primary PM2.5. 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-3) are larger than within an MSA with ~80% of the variation due to secondary PM2.5. 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-3) due to both regional and intra-urban contributions; on average, 65% of the national exposure contrast is due to secondary PM2.5 with the remaining from the primary PM2.5 (cooking and mobile source 26%, other 9%).ImpactOur study provides a comprehensive analysis of the sources and processes that contribute to exposure contrasts of PM2.5 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 PM2.5 exposure contrasts. The study also highlights the advantages of different study designs for investigating the health impacts of specific PM2.5 components. The findings provide novel insights that can inform public health policies aimed at reducing PM2.5 exposure and advance the understanding of the epidemiological study outcomes.

Dataset Information

Long-term exposure to PM_2.5 major components and mortality in the southeastern United States.

Background

Methods

Results

Conclusion

Publications

Long-term exposure to PM<sub>2.5</sub> major components and mortality in the southeastern United States.

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Dataset Information

Long-term exposure to PM2.5 major components and mortality in the southeastern United States.

Background

Methods

Results

Conclusion

Publications

Long-term exposure to PM<sub>2.5</sub> major components and mortality in the southeastern United States.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Long-term exposure to PM_2.5 major components and mortality in the southeastern United States.