Polycyclic aromatic hydrocarbons in urban and rural residential soils, levels, composition profiles, source identification and health risk & hazard

Abstract

The presence of PAHs in soil and the close proximity of soils to humans may lead to human exposure through various pathways. Therefore, levels of priority sixteen PAHs in soils were measured for human and environmental health risk assessments. No recent study on human and environmental health effects due to PAHs in soils is available for Delhi. The levels of total PAHs in soils ranged between 213–851 μg kg−1 with the mean of 550 ± 55 μg kg−1, which was comparatively lower in rural area. Seven carcinogenic PAHs (7CPAHs) accounted for 28.6% of ∑16PAHs. However, benzo(a)pyrene toxicity equivalency (BaPTE) of 7CPAHs accounted for 98.2% to ∑BaPTE. Lifetime average daily dose (LADD) of PAHs through soil for human adults and children was 9.43 × 10−8 mg kg−1 d−1 and 3.53 × 10−7 mg kg−1 d−1, respectively. The estimated incremental lifetime cancer risk (ILCR) for children (4.80 × 10−5) was comparatively higher than adults (1.29 × 10−5). The index of additive cancer risk (IACR), potential threat to potable groundwater water quality from leaching of carcinogenic PAHs from soil were also estimated and presented. The observed levels of PAHs in soils and their human health risk and environmental health hazard at different locations were assessed using recommended guidelines.