Assessment of Ambient Air Toxics and Wood Smoke Pollution among Communities in Sacramento County.

Steven G Brown,Amy P Sullivan,Janice Lam Snyder,Nathan R Pavlovic,Stephen D’Andrea,Joseph Hanson,Hilary R Hafner,Michael C Mccarthy

doi:10.3390/ijerph17031080

Abstract

Ambient air monitoring and phone survey data were collected in three environmental justice (EJ) and three non-EJ communities in Sacramento County during winter 2016–2017 to understand the differences in air toxics and in wood smoke pollution among communities. Concentrations of six hazardous air pollutants (HAPs) and black carbon (BC) from fossil fuel (BCff) were significantly higher at EJ communities versus non-EJ communities. BC from wood burning (BCwb) was significantly higher at non-EJ communities. Correlation analysis indicated that the six HAPs were predominantly from fossil fuel combustion sources, not from wood burning. The HAPs were moderately variable across sites (coefficient of divergence (COD) range of 0.07 for carbon tetrachloride to 0.28 for m- and p-xylenes), while BCff and BCwb were highly variable (COD values of 0.46 and 0.50). The BCwb was well correlated with levoglucosan (R2 of 0.68 to 0.95), indicating that BCwb was a robust indicator for wood burning. At the two permanent monitoring sites, wood burning comprised 29–39% of the fine particulate matter (PM2.5) on nights when PM2.5 concentrations were forecasted to be high. Phone survey data were consistent with study measurements; the only significant difference in the survey results among communities were that non-EJ residents burn with indoor devices more often than EJ residents.

Highlights

Wood smoke from residential burning is the largest source of wintertime particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5 ) emissions in the Sacramento, California, area, accounting for more than 50 percent of direct wintertime PM2.5 emissions [1]
The survey results show no significant differences between environmental justice (EJ) and non-EJ communities in the type of device owned, fraction of homes burning with fireplaces, fraction of homes burning day and night, fraction of homes burning only at night, or fraction of homes with Environmental Protection Agency (EPA)-certified burning devices
In this first detailed community monitoring study during the winter in Sacramento County, we found that concentrations of six hazardous air pollutants (HAPs) and BCff were significantly higher at EJ communities than at non-EJ communities

Summary

Introduction

Wood smoke from residential burning is the largest source of wintertime particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5 ) emissions in the Sacramento, California, area, accounting for more than 50 percent of direct wintertime PM2.5 emissions [1]. Ambient pollution studies have indicated that wood smoke is a major source of wintertime PM2.5 in Sacramento [2,3]. In Sacramento, this wintertime source of PM2.5 is important; residential burning emissions typically occur in the evening or overnight, when they can be trapped in the shallow boundary layer that often forms in the Sacramento Valley. The resultant high-concentration PM2.5 events over the course of an evening can have acute health impacts [4,5], and exposure to wood burning emissions have been linked to health effects [5,6,7]. Public Health 2020, 17, 1080; doi:10.3390/ijerph17031080 www.mdpi.com/journal/ijerph

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