Department of Environmental Management and Toxicology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria.
Laboratory for Ecotoxicology and Environmental Forensics, University of Benin, Benin City, Nigeria.
Environ Toxicol Chem. 2021 Jan;40(1):261-271. doi: 10.1002/etc.4906. Epub 2020 Dec 9.
There is an intrinsic link between polycyclic aromatic hydrocarbons (PAHs) accumulated in soils and increased health risk to humans after exposure to contaminated soil via ingestion, inhalation of particulates carrying PAHs, and direct contact with polluted soils. However, the assessment of PAH contamination in most developing countries fails to consider health risk assessment. Therefore, a comprehensive study was conducted to determine the concentration, source, toxicity, and human health risks of 16 PAHs in an urban area in Warri, Delta State, in the Niger Delta region of Nigeria. The results showed varying contamination levels for PAH in soil samples from all sampling points, with benzo[a]anthracene (BaP; at 338.81 μg/kg) being the most abundant at all 9 sampling stations. The highest total concentration of PAH was observed at station 5 (1230.98 μg/kg), which was closest to a flow station. Further comparison with PAH contamination standards showed that soils from stations 1 and 2 were weakly contaminated (<600 μg/kg), and soil samples from stations 3, 4, 6, 7, and 9 were moderately contaminated (<1000 μg/kg). Soil samples from stations 5 and 8 were observed to be heavily contaminated (>1000 μg/kg). The BaP estimates for soil samples obtained for stations 3 to 9 were higher than the BaP soil screening value (15 μg/kg), indicating a carcinogenic potential of soil samples. The results also showed that the incremental lifetime cancer risk estimates for PAH in the soil for adults and children were above the recommended threshold (10 ) for ingestion and dermal contact, implying that exposure to contaminated soil could lead to cancers in adults and children. Currently, there are no regional or national standards for PAHs in soil that would indicate an increased likelihood for human exposure and subsequent health issues. Environ Toxicol Chem 2021;40:261-271. © 2020 SETAC.
土壤中多环芳烃（PAHs）的积累与人类接触受污染土壤后通过摄入、吸入携带 PAHs 的颗粒物以及直接接触受污染土壤而导致的健康风险增加之间存在内在联系。然而，在大多数发展中国家，对 PAH 污染的评估都没有考虑健康风险评估。因此，在尼日利亚尼日尔三角洲地区的瓦里（Warri）进行了一项城市地区土壤中 16 种多环芳烃的浓度、来源、毒性和人体健康风险的综合研究。结果表明，所有采样点的土壤样本中 PAH 的污染程度不同，在所有 9 个采样站中，苯并[a]蒽（BaP；338.81μg/kg）含量最丰富。在离一个流量站最近的 5 号采样站（1230.98μg/kg）发现了最高的总多环芳烃浓度。与多环芳烃污染标准进一步比较表明，1 号和 2 号采样站的土壤污染较轻（<600μg/kg），而 3 号、4 号、6 号、7 号和 9 号采样站的土壤样本则为中度污染（<1000μg/kg）。5 号和 8 号采样站的土壤样本则为重度污染（>1000μg/kg）。对于 3 号至 9 号采样站获得的土壤样本，BaP 估计值高于 BaP 土壤筛选值（15μg/kg），表明土壤样本具有致癌潜力。结果还表明，成人和儿童的土壤中多环芳烃的增量终生癌症风险估计值超过了推荐的（10 ）阈值（用于摄入和皮肤接触），这意味着接触受污染的土壤可能会导致成人和儿童患上癌症。目前，土壤中多环芳烃还没有区域或国家标准，这表明人类接触的可能性增加以及随后的健康问题。Environ Toxicol Chem 2021;40:261-271. © 2020 SETAC.
