Concentrations, Source Identification and Potential Ecological and Human Health Risks Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Agricultural Soils of Hamedan County, West of Iran

Abstract

ABSTRACT This study was performed to examine the possible ecological impact of sixteen PAHs listed as priorities by the US EPA in the agricultural soils of Hamedan County (ASHC), west of Iran, in 2021. In so doing, 36 surface soil samples were collected from 12 agriculturally-related sampling locations. The soxhlet method was employed to extract analytes, and the gas chromatography/mass spectrometry (GC-MS) method was utilized to identify the chemicals PAHs in the samples. Based on the data, there were 16PAHs (∑16PAHs) in total concentrations (µg kg−1), ranging from 435 to 3292, with an average of 1806. The PAH profiles were dominated by PAHs with larger molecular weights (≥4 rings), accounting for 78% of the total mass of 16PAH. Based to Molecular Diagnostic Ratios (MDRs) the majority of PAH molecules were found to have pyrogenic origins. As the results indicated, Indeno(1,2,3-cd)pyrene and benz(ghi)perylene posed very little ecological harm to soil organisms, based on the data, while other PAHs reflected significant environmental risks in these soils. All of the stations were identified as being in the low-risk group by the overall ecological risk of 16PAH in surface soil samples. The total incremental lifetime cancer risks (Total ILCRs) of PAH compounds for children with an average of 7.51 × 10−7 (ranging from 1.66 × 10−7 to 1.50 × 10−6) indicated negligible potential cancer and human health risks; whereas, the total ILCRs for adults with an average of 1.59 × 10−6 (ranging from 3.65 × 10−7 to 3.30 × 10−6) showing a low potential carcinogenic risk of PAH compounds in the study location. These findings imply that eating food cultivated in contaminated soils and directly digesting soil may be harmful to human health. Therefore, regular and periodic monitoring of agricultural soils is recommended to maintain consumer’s health of agricultural products.