Geochemistry, sources, human health and ecological risk of trace elements in soil from the Mirsarai export processing zone, southeastern coast of Bangladesh

Abstract

Rapid industrial growth in Export Processing Zones (EPZs) has intensified concerns regarding trace element accumulation in soils and its environmental consequences. This study quantified twelve trace elements in soils from the Mirsarai Export Processing Zone using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) to evaluate contamination status, spatial distribution, potential sources, and associated ecological and human health risks. The results revealed significant enrichment of all trace elements except Fe, with pollution indices and spatial analysis indicating considerable contamination and heterogeneous distribution across the study area. Pearson correlation and principal component analysis (PCA) suggested that elevated trace element concentrations were primarily associated with industrial waste inputs. Ecological risk assessment identified Se as the dominant contributor (ER = 601.40), followed by As (149.85) and Hg (106.45). An innovative Source-Pathway-Receptor (SPR) model linked industrial activities with contaminant transport and environmental risks, identifying textile dyeing, leather processing, electroplating, battery manufacturing, metal finishing, and electronics industries as the principal sources of As, Cr, Cu, Zn, Pb, Cd, Ni, and Co. Non-carcinogenic risk assessment showed that Co posed the highest risk to children (HI = 8.54), followed by Mn (2.62), Cr (2.05), and As (1.45), whereas only Co exceeded the acceptable threshold for adults (HI = 2.25). Children experienced approximately 3.1-fold higher carcinogenic risk than adults, with Ni, Cr, and As exceeding the USEPA acceptable limit (1.0E−04). Monte Carlo simulation further confirmed a mean total carcinogenic risk of 1.58E−04 for children, highlighting the urgent need for pollution control and sustainable environmental management in rapidly industrializing EPZs.