Health risk assessment of trace elements exposure through the soil-plant (maize)-human contamination pathway near a petrochemical industry complex, Northeast China

The trace elements contamination of agricultural soils near petrochemical industry complexes is a concern due to the risk of accumulating in food systems and subsequently affecting human health. We measured representative trace elements (Cu, Ni, Cr, Pb, Zn, Pb, Hg and As) through the soil-plant (maize)-human contamination pathway near a petrochemical industry complexes in an agricultural region from September 20 to 28, 2016. We found that the soil was mildly to moderately polluted by multiple trace elements, which was also confirmed by the contamination factor and enrichment factor values. Cd (enrichment factor = 2.28), Cu (2.75), Zn (1.85) and Pb (1.70) should be given more attention and prioritized over the other trace elements due to their higher potential risks. Furthermore, the trace elements contamination in maize grains was lower than the corresponding limits. The sequence of the transfer coefficient values was Zn > Cd > Cu > Hg > Ni > As > Cr > Pb. Maize grain safety was threatened mainly by Zn, Cd and Cu. There was no risk to humans through soil ingestion, while a potential health risk from maize grain consumption existed. Children were more sensitive than adults to the non-carcinogenic risks of maize grain consumption. Trace element As was found to be the priority metal for risk control. For carcinogenic risk, adults were more sensitive than children; As, Cr and Cd were the priority metals for risk control, with CRₘₐᵢzₑ values exceeding the risk threshold (1 × 10⁻⁴). Overall, strict, intensive monitoring, especially of Cr and Cd, and soil protection measures are needed to prevent any furthertrace elements contamination and to ensure food safety. This study also provides a reference for similar studies worldwide.