Source profiling, pollution and health risk assessment of heavy metals in agricultural soils around an industrial cluster using PCA and GIS-assisted PMF.

The continuous release of heavy metals (HMs) from nearby industries leads to the contamination of surrounding agricultural areas. This study employed an integrated approach, combining contamination factor (CF), enrichment factor (EF) and geo-accumulation index (I) for pollution assessment, alongside source apportionment using principal component analysis (PCA) and Geographic Information System (GIS)-based positive matrix factorization (PMF), to evaluate HM contamination in agricultural soils of the northeast Guntur district, India. The mean concentrations of HMs, Cu, Cr, Zn, Ni, Cd and Pb exceeded the Indian natural background soil values by 2.59, 1.21, 2.24, 2.09, 1.15 and 1.4 respectively. Pollution indices revealed high contamination for Ni (CF = 2.21) and Cr (CF = 2.05), with Cr showing moderate enrichment (EF ≈ 1.5) and contamination (I = 0.75). PCA identified three components explaining 78.37% of the total variation while GIS-based PMF identified industrial discharges, waste incineration, agriculture and vehicular and industrial emissions as pollution sources. Ni, Cu and Cr were identified as the primary contaminants, with industrial emissions, vehicular traffic and agricultural activities as key contributors to HM pollution. Cr accounted for ~ 80% of the total hazard index, posing significant non-carcinogenic risks for children via ingestion. Carcinogenic risks through ingestion of Ni and Cr were 2.8 and 1.9 times higher than acceptable levels for adults and 3.9 and 2.6 times higher than acceptable levels for children. Additionally, the high bioconcentration factor (BCF) of Lantana viburnoides (Forssk.) with a BCF of 18.29 for Cd suggests a potential environmental hazard. It is imperative to monitor emissions rigorously to safeguard soil quality and optimize industry standards in this region.