Climate impact on ambient PM2.5 elemental concentration in the United States: A trend analysis over the last 30 years

Weeberb J Requia; Iny Jhun; Brent A Coull; Petros Koutrakis

doi:10.1016/j.envint.2019.05.082

Climate impact on ambient PM_2.5 elemental concentration in the United States: A trend analysis over the last 30 years

Environ Int. 2019 Oct:131:104888. doi: 10.1016/j.envint.2019.05.082. Epub 2019 Jul 11.

Authors

Weeberb J Requia¹, Iny Jhun², Brent A Coull³, Petros Koutrakis⁴

Affiliations

¹ Harvard University, Department of Environmental Health, School of Public Health, Boston, MA, United States. Electronic address: wjrequia@hsph.harvard.edu.
² Harvard University, Harvard Medical School, Boston, MA, United States.
³ Harvard University, Department of Biostatistics, School of Public Health, Boston, MA, United States.
⁴ Harvard University, Department of Environmental Health, School of Public Health, Boston, MA, United States.

PMID: 31302483
DOI: 10.1016/j.envint.2019.05.082

Abstract

Weather impacts on the chemical composition of PM_2.5 varies significantly over space and time given the diversity of particle components and the complex mechanisms governing particle formation and removal. In this study, we employed generalized additive models (GAMs) to estimate weather-associated changes in PM_2.5 composition in the US during 1988-2017. We considered seven components of ambient PM_2.5, which included elemental carbon (EC), organic carbon (OC), nitrate, sulfate, sodium, ammonium, and silicon. The impact of long-term weather changes on each PM_2.5 component was defined in our study as "weather penalty". During our study period, temperature increased in four regions, including the Industrial Midwest and Northeast during the warm and cold season; and Upper Midwest and West in the cold season. Wind speed decreased in the both seasons. Relative humidity increased in the warm season and decreased in the cold season. The weather changes between 1988 and 2017 were associated with most PM_2.5 components during both warm and cold seasons. The direction and the magnitude of the weather penalty varied considerably over the space and season. In the warm season, our findings suggest a nationwide weather penalty for EC, OC, nitrate, sulfate, sodium, ammonium, and silicon of 0.04, 0.21, 0.04, 0.35, -0.01, 0.05, and 0.01 μg/m³, respectively. In the cold season, the estimated total penalty was 0.04, 0.21, 0.06, 0.04, -0.01, -0.02, and 0.02 μg/m³, respectively.

Keywords: Air pollution; PM(2.5) speciation; Trend analysis; Weather.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Air Pollutants / analysis*
Climate Change*
Climate*
Environmental Monitoring
Models, Theoretical
Particle Size
Particulate Matter / analysis*
Seasons
United States
Weather

Substances

Air Pollutants
Particulate Matter