Multi-year Analyses Reveal Different Trends, Sources, and Implications for Source-Related Human Health Risks of Atmospheric Polycyclic Aromatic Hydrocarbons in the Canadian Great Lakes Basin

Polycyclic
aromatic hydrocarbons (PAHs) are of high concern to
public health due to their carcinogenic and mutagenic properties.
Here, we present the first comprehensive and quantitative analysis
of sources, potential source regions according to source sectors and
source-related human health risks of multi-year atmospheric measurements
of PAHs in the Canadian Great Lakes Basin (GLB). The highest PAH concentrations
were observed at a rural residential site (Egbert), followed by two
regionally representative remote sites [Point Petre (PPT) and Burnt
Island]. The levels of most PAHs in the GLB atmosphere significantly
decreased between 1997 and 2017, broadly consistent with the decreasing
trends of anthropogenic emissions. Coal, liquid fossil fuel, and biomass
burning were the most common potential sources. The potential source
regions for most source sectors were identified south or southwest
of the sampling sites. Risk assessment suggests potential health risks
associated with the inhalation of atmospheric PAHs. On a positive
note, health risks from coal combustion, liquid fossil fuel combustion,
and petrogenic sources at PPT significantly decreased, directly demonstrating
the success of emission control in reducing health impacts. In contrast,
the health risk from forest fire-related PAH emissions may play an
increasing role in the future due to climate change.

多环芳烃（Polycyclic Aromatic Hydrocarbons，PAHs）因其致癌性与致突变性，受到公共卫生领域的高度关注。
本研究针对加拿大五大湖盆地（Great Lakes Basin，GLB）内多年大气多环芳烃监测数据，首次开展了污染源、基于源类的潜在源区以及污染源相关人体健康风险的全面定量分析。
监测数据显示，农村居民点埃格伯特（Egbert）的多环芳烃浓度最高，其次是两个具备区域代表性的偏远监测点——皮特点（Point Petre，PPT）与伯恩特岛（Burnt Island）。1997年至2017年间，五大湖盆地大气中多数多环芳烃的浓度显著下降，这与人为排放的整体下降趋势基本吻合。
煤炭燃烧、液体化石燃料燃烧与生物质燃烧是最主要的潜在污染源。多数源类的潜在源区均位于采样点以南或西南方向。健康风险评估结果表明，吸入大气中的多环芳烃存在潜在健康风险。
值得关注的是，皮特点（PPT）地区由煤炭燃烧、液体化石燃料燃烧以及石油类污染源（petrogenic sources）引发的健康风险显著降低，直接印证了排放管控在降低健康影响方面的成效。与之形成对照的是，受气候变化影响，未来森林火灾排放的多环芳烃所带来的健康风险可能会逐年上升。