Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada.
Ryerson University, Toronto, Ontario M5B 2K3, Canada.
Environ Sci Technol. 2022 Mar 1;56(5):2959-2967. doi: 10.1021/acs.est.1c04299. Epub 2022 Feb 11.
22 alkylated polycyclic aromatic hydrocarbons (alk-PAHs) were characterized in ambient air individually for the first time in urban and semi-urban locations in Toronto, Canada. Five unsubstituted PAHs were included for comparison. Results from the measurements were used to estimate benzo[]pyrene equivalent toxicity (BaPeq) of individual compounds in order to investigate the significance of a single compound in contributing to the overall toxic equivalency (TEQ) of air mixtures. To determine which compounds merit further investigation, BaPeq values of individual compounds were compared to the measured BaP toxicity. Our results showed that both unsubstituted and alkylated PAHs were more abundant in the urban area (38 and 30%, respectively). Benzo[]pyrene levels at the urban location exceeded Ontario's 24 h guideline (40% of the events), and on average, it was 5 times higher than that at the semi-urban area. Gas-phase two- and three-ring compounds contributed up to 39% (urban) and 76% (semi-urban) of the TEQ of all compounds analyzed. Some alk-PAHs such as 7,12-dimethylbenzo[]anthracene had a huge impact on the toxicity of urban air, and its BaPeq was on average 8 times higher than that of BaP. We emphasize that the toxic impact of alkylated and gaseous PAHs, which is not routinely included in many air monitoring programs, is significant and should not be neglected.
22 种烷基多环芳烃（alk-PAHs）在加拿大多伦多的城市和半城市地区首次被单独作为环境空气中的特征污染物进行了研究。同时还包括了 5 种未取代的多环芳烃作为比较。测量结果被用来估计各个化合物的苯并[a]芘等效毒性（BaPeq），以研究单个化合物对空气混合物总毒性等效（TEQ）的贡献程度。为了确定哪些化合物值得进一步研究，将单个化合物的 BaPeq 值与实测的苯并[a]芘毒性进行了比较。我们的研究结果表明，无论是未取代的还是烷基化的多环芳烃，在城市地区都更为丰富（分别为 38%和 30%）。城市地区的苯并[a]芘含量超过了安大略省的 24 小时指导值（40%的事件），平均水平比半城市地区高出 5 倍。气相中二环和三环化合物对所有分析化合物的 TEQ 贡献高达 39%（城市）和 76%（半城市）。一些烷基化多环芳烃，如 7,12-二甲基苯并[a]蒽，对城市空气的毒性有巨大影响，其 BaPeq 平均比苯并[a]芘高出 8 倍。我们强调，烷基化和气态多环芳烃的毒性影响在许多空气监测计划中并未常规包括，但其影响显著，不应被忽视。
