Full Title: Composition, Emissions, and Air Quality Impacts of Hazardous Air Pollutants in Unburned Natural Gas from Residential Stoves in California
Author(s): Eric Lebel, Drew Michanowicz, Kelsey Bilsback, Lee Ann Hill, Jackson Goldman, Jeremy Domen, Jessie Jaeger, Angélica Cruz, Seth B.C. Shonkoff
Publisher(s): Environmental Science and Technology
Publication Date: September 30, 2022
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The presence of hazardous air pollutants (HAPs) entrained in end-use natural gas (NG) is an understudied source of human health risks. We performed trace gas analyses on 185 unburned NG samples collected from 159 unique residential NG stoves across seven geographic regions in California. Our analyses commonly detected 12 HAPs with significant variability across
region and gas utility. By applying previously reported NG and methane emission rates throughout California’s transmission,
storage, and distribution systems, we estimated statewide benzene emissions of 4,200 (95% CI: 1,800−9,700) kg yr−1 that are currently not included in any statewide inventories equal to the annual benzene emissions from nearly 60,000 light-duty gasoline vehicles. Additionally, we found that NG leakage from stoves and ovens while not in use can result in indoor benzene concentrations that can exceed the California Office of Environmental Health Hazard Assessment 8-h Reference Exposure Level of 0.94 ppbv benzene concentrations comparable to environmental tobacco smoke. This study supports the need to further improve our understanding of leaked downstream NG as a source of health risk.