Impact of Changing in Ship Emissions on Water-Soluble Iron in Fine Particulate Matter Between 2009-2018 in Saint John, NB
RIN TAKAI, Jenny P.S. Wong, Mount Allison University
Abstract Number: 356
Working Group: Aerosol Processes and Properties in Changing Environments in the Anthropocene
Abstract
Human exposure to fine particulate matter (PM2.5) pollution is linked to acute and chronic cardiovascular, pulmonary diseases, with numerous epidemiological and toxicological studies demonstrating that water-soluble iron (WS-Fe) in PM2.5 is an important contributor to these adverse health effects. Although the predominant source of Fe from mineral dust is initially emitted in an insoluble form at the time of emission, Fe solubility measured in ambient PM2.5 is greater, indicating the contribution of unknown WS-Fe primary and secondary sources (i.e., atmospheric chemical processing resulting in the iron dissolution). While studies have shown that proton-mediated and ligand-mediated reactions convert insoluble Fe into a soluble form during atmospheric transport in Ontario, the factors controlling WS-Fe in Atlantic Canada, specifically in Saint John, New Brunswick (NB), remain unclear. In addition, since Saint John is known as the largest port by cargo volume in Atlantic Canada, emissions of sulfur dioxide from large marine vessels can potentially influence WS-Fe production, as sulfur dioxide affects aerosol pH conditions by forming sulfuric acid that affects iron dissolution. Therefore, the impact of implementing the North American Emission Control Area (NAECA) low-sulfur fuel regulations on WS-Fe in Saint John is explored in this study. Results demonstrate that the implementation of low-sulfur fuel regulations has led to a reduction in WS-Fe: (1) directly, by decreasing primary emissions of WS-Fe from ships, and (2) indirectly, by a potential reduction in sulfur dioxide emission, which influences aerosol pH and consequently, secondary production of WS-Fe through atmospheric processing of iron-containing aerosols.