Emerging risks of toxic metal(loid)s in soil-vegetables influenced by steel-making activities and isotopic source apportionment

TLDR

Industrial activities degrade nearby agricultural lands by accumulating toxic elements in soils and crops, yet source partitions and transfer processes remain poorly understood in steel‑making regions, underscoring the need for remediation to protect food safety. The study assesses pollution levels, health risks, and provenance of multiple toxic elements in vegetables from farmlands near a steel‑making plant. The vegetables exhibited high‑level contamination of Tl, As, Pb, Cd, Cr, Cu, and Mn above permissible limits, with hazard quotient analysis indicating significant health risks—particularly for children—and isotopic mixing models attributing 35–80 % of Pb and As contamination to steel‑making activities.

Abstract

Industrial activities tend to deteriorate adjacent agricultural lands due to accumulation of potentially toxic elements in soils and crops. However, better understanding of their distinctive source partitions and transfer process remains insufficient in steel-making area. The paper focuses on the pollution levels, health risks, and provenance identification of Tl, As, Pb, Cu, Ni, Co, Sb, Cd, Zn, Be, Cr, Fe, Mn, Mo, Sn, and V in common vegetables from different farmlands near a steel-making plant. The results showed that the Tl, As, Pb, Cd, Cr, Cu and Mn were of high-level contamination in soils and generally above the maximum permissible level (MPL). Calculation using hazard quotients (HQ) exhibited that consumption of the studied vegetables may entail significant health risks to residents, especially for children, resulting from the elevated contents of Tl, As and associated toxic elements. Calculation by binary mixing model using Pb isotopic compositions suggested that steel-making activities contributed to 35–80% of the contamination of Pb and As in vegetables. It is necessary to adopt appropriate remediation measures to mitigate the farmland contamination and ensure the food safety of the agricultural products.