Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India.
Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India; DST-Mahamana Centre of Excellence in Climate Change Research, Banaras Hindu University, Varanasi, India.
Chemosphere. 2023 Nov;340:139943. doi: 10.1016/j.chemosphere.2023.139943. Epub 2023 Aug 23.
Abundance of fine particulate-bound 16 priority polycyclic aromatic hydrocarbons (PAHs) was investigated to ascertain its sources and potential carcinogenic health risks in Varanasi, India. The city represents a typical urban settlement of South Asia having particulate exposure manyfold higher than standard with reports of pollution induced mortalities and morbidities. Fine particulates (PM) were monitored from October 2019 to May 2020, with 32% of monitoring days accounting ≥100 μgm of PM concentration, frequently from November to January (99% of monitoring days). The concentration of 16 priority PAHs varied from 24.1 to 44.6 ngm (mean: 33.1 ± 3.2 ngm) without much seasonal deviations. Both low (LMW, 56%) and high molecular weight (HMW, 44%) PAHs were abundant, with Fluoranthene (3.9 ± 0.4ngm) and Fluorene (3.5 ± 0.3ngm) emerged as most dominating PAHs. Concentration of Benzo(a)pyrene (B(a)P, 0.5 ± 0.1ngm) was lower than the national standard as it contributed 13% of total PAHs mass. Diagnostic ratios of PAH isomers indicate predominance of pyrogenic sources including emissions from biomass burning, and both from diesel and petrol-driven vehicles. Source apportionment using receptor model revealed similar observation of major PAHs contribution from biomass burning and fuel combustion (54% of source contribution) followed by coal combustion for residential heating and cooking purposes (44%). Potential toxicity of B[a]P equivalence ranged from 0.003 to 1.365 with cumulative toxicity of 2.13ngm. Among the PAH species, dibenzo[h]anthracene contributed maximum toxicity followed by B[a]P, together accounting 86% of PAH induced carcinogenicity. Incremental risk of developing cancer through lifetime exposure (ILCR) of PAHs was higher in children (3.3 × 10) with 56% contribution from LMW PAHs, primarily through ingestion and dermal contact. Adults in contrast, were more exposed to inhale airborne PAHs with cumulative ILCR of 2.2 × 10. However, ILCR to PM exposure is probably underestimated considering unaccounted metal abundance thus, require source-specific control measures.
本研究旨在调查印度瓦拉纳西市细颗粒物中结合的 16 种优先多环芳烃（PAHs）的丰度，以确定其来源及其潜在的致癌健康风险。该市是南亚典型的城市聚居地，其颗粒物暴露水平比标准水平高出数倍，有报道称污染导致死亡率和发病率上升。从 2019 年 10 月到 2020 年 5 月，我们对细颗粒物（PM）进行了监测，其中 32%的监测日 PM 浓度≥100 μgm，且经常出现在 11 月至 1 月（99%的监测日）。16 种优先 PAHs 的浓度在 24.1 至 44.6 ngm 之间（平均值：33.1 ± 3.2 ngm），季节性差异不大。低分子量（LMW，56%）和高分子量（HMW，44%）PAHs 都很丰富，荧蒽（3.9 ± 0.4ngm）和芴（3.5 ± 0.3ngm）是最主要的 PAHs。苯并[a]芘（B[a]P）的浓度（0.5 ± 0.1ngm）低于国家标准，因为它仅占总 PAHs 质量的 13%。PAH 异构体的诊断比值表明，存在来自生物质燃烧、柴油和汽油驱动车辆排放等多种人为源的主导性。受体模型的源分配表明，主要 PAHs 主要来自生物质燃烧和燃料燃烧（占源贡献的 54%），其次是用于住宅取暖和烹饪的煤燃烧（占 44%）。B[a]P 当量的潜在毒性范围为 0.003 至 1.365，累积毒性为 2.13ngm。在 PAH 种中，二苯并[a,h]蒽的毒性最大，其次是 B[a]P，它们共同占 PAH 致癌性的 86%。通过终生接触（ILCR）PAHs，儿童（3.3×10）的癌症发病风险更高，其中 LMW PAHs 占 56%，主要通过摄入和皮肤接触。相比之下，成年人则更多地通过吸入空气传播的 PAHs 暴露，累积 ILCR 为 2.2×10。然而，考虑到未被计算的金属丰度，PAHs 对 PM 暴露的增量风险可能被低估，因此需要采取针对特定来源的控制措施。
