Comprehensive assessment of heavy metal contamination in soil-plant systems and health risks from wastewater-irrigated vegetables

Abstract

A research study examined the origins, human health impacts, and risks associated with pollutants in vegetables grown in soil irrigated with wastewater. The study analyzed 164 samples from water sources, irrigated soil, and harvested vegetables for eight heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) using atomic absorption spectrophotometry. The focus was on the potential health effects of consuming heavy metal-contaminated vegetables grown in wastewater-irrigated soil. The findings revealed significant accumulation of heavy metals in soil and plants from Mianwali, Pakistan, posing potential health risks to consumers. When compared to vegetables produced with freshwater irrigation, the concentration levels of heavy metals in the soil irrigated with untreated wastewater were significantly greater (P≤0.001) and above the recommended limits set by the World Health Organization (WHO). The results showed that heavy metals in the soil had significantly increased, and crops had subsequently absorbed these metals. Produce raised in soil watered with wastewater showed higher levels of heavy metals than the US Environmental Protection Agency (EPA) and the WHO recommended. Among the veggies, lead (Pb) and cadmium (Cd) were found to have higher Hazardous Quotient Indices (HRIs) than one. This indicates that both adults and children may have been exposed to dangerous levels of these metals. Additionally, for Brassica oleracea, Raphanus sativus, and Spinacia oleracea, nickel (Ni) surpassed HRIs larger than 1, indicating a significant health risk connected to these veggies' ingestion.