Evaluating the effectiveness of low-sulphur marine fuel regulations at improving urban ambient PM2.5 air quality: Source apportionment of PM2.5 at Canadian Atlantic and Pacific coast cities with implementation of the North American Emissions Control Area

Angelos T Anastasopolos; Philip K Hopke; Uwayemi M Sofowote; Dennis Mooibroek; Joyce J Y Zhang; Mathieu Rouleau; Hui Peng; Navin Sundar

doi:10.1016/j.scitotenv.2023.166965

Evaluating the effectiveness of low-sulphur marine fuel regulations at improving urban ambient PM_2.5 air quality: Source apportionment of PM_2.5 at Canadian Atlantic and Pacific coast cities with implementation of the North American Emissions Control Area

Sci Total Environ. 2023 Dec 15:904:166965. doi: 10.1016/j.scitotenv.2023.166965. Epub 2023 Sep 10.

Authors

Angelos T Anastasopolos¹, Philip K Hopke², Uwayemi M Sofowote³, Dennis Mooibroek⁴, Joyce J Y Zhang⁵, Mathieu Rouleau⁵, Hui Peng⁶, Navin Sundar⁷

Affiliations

¹ Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada. Electronic address: angelos.anastasopolos@canada.ca.
² Department of Public Health Sciences, University of Rochester Medical Center, Rochester, NY, USA.
³ Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, Conservation and Parks, Toronto, Ontario, Canada.
⁴ National Institute for Public Health and the Environment, Bilthoven, Netherlands.
⁵ Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada.
⁶ Environmental Protection Branch, Environment and Climate Change Canada, Ottawa, Ontario, Canada.
⁷ Environmental Protection Branch, Environment and Climate Change Canada, Vancouver, British Columbia, Canada.

PMID: 37699485
DOI: 10.1016/j.scitotenv.2023.166965

Abstract

Ambient fine size fraction particulate matter (PM_2.5) sources were resolved by positive matrix factorization at two Canadian cities on the Atlantic and Pacific coast over the 2010-2016 period, corresponding to implementation of the North American Emissions Control Area (NA ECA) low-sulphur marine fuel regulations. Source types contributing to local PM_2.5 concentrations were: ECA regulation-related (residual oil, anthropogenic sulphate), urban transportation and residential (gasoline, diesel, secondary nitrate, biomass burning, road dust/soil), industry (refinery, Pb-enriched), and largely natural (biogenic sulphate, sea salt). Anthropogenic sources accounted for approximately 80 % of PM_2.5 mass over 2010-2016. Anthropogenic and biogenic sources of PM_2.5-sulphate were separated and apportioned. Anthropogenic PM_2.5-sulphate was approximately 2-3 times higher than biogenic PM_2.5-sulphate prior to implementation of the NA ECA low-S marine fuel regulations, decreasing to 1-2 times higher after regulation implementation. Non-marine anthropogenic sources (gasoline, road dust, local industry factors) were shown to together contribute 38 % - 45 % of urban PM_2.5. At both coastal cities, the residual oil and anthropogenic sulphate factors clearly reflected the effects of the low-S fuel regulations at reducing primary and secondary sulphur-related PM_2.5 emissions. Comparing a pre-regulation and post-regulation period, residual oil combustion PM_2.5 decreased by 0.24-0.25 μg/m³ (94%-95 % decrease) in both cities and anthropogenic sulphate PM_2.5 decreased by 0.78 μg/m³ in Halifax (47 % decrease) and 0.71 μg/m³ in Burnaby (58 % decrease). Regulation-related PM_2.5 across these factors decreased by approximately 1 μg/m³ after regulation implementation, providing a quantified lower estimate of the beneficial influence of the regulations on urban ambient PM_2.5 concentrations. Further reductions in coastal city ambient PM_2.5 may best consider air quality strategies that include multiple sources, including marine shipping and non-marine anthropogenic source types given this analysis found that marine vessel emissions remain an important source of urban ambient PM_2.5.

Keywords: Dispersion-normalized positive matrix factorization (DN-PMF); Fine particulate matter (PM(2.5)); Port city; Regulation; Source apportionment; Sulphate.