Total arsenic contamination in soil, vegetables, and fruits and its potential health risks in the Chitral Valley, Pakistan

Total arsenic (TAs) contamination is a serious health issue that affects many parts of the world. The sources of TAs in the Himalayas and Hindu Kush Mountains are rocks containing sulfide minerals and coal. The current study investigated the concentrations of TAs in soil, vegetables, and fruits collected from the Chitral Valley in the Hindukush Mountains of Pakistan. Vegetables consisted of Solanum tuberosum (potatoes), Mentha spicata (mint), Chenopodium album (goosefoot), Coriandrum sativum (coriander), Cucumis sativus (cucumber), Amaranthus viridis (green amaranth), and Medicago sativa (alfalfa); and fruits consisted of Prunus armeniaca (apricot), Morus alba (mulberry), Juglans regia (nut), Malus domestica (apple), and Vitis vinifera (grapes). The average concentration of TAs was the highest in the Gabur soils and lowest in the Bamborait soils. In vegetables, the highest TAs concentration was found in goosefoot (11.11 ± 1.9 mg·kg⁻¹) and the lowest in cucumbers (1.38 ± 0.3 mg·kg⁻¹). In fruits, the highest TAs concentration was found in grapes (4.3 ± 0.5 mg·kg⁻¹), while no TAs concentration was detected in nuts (± indicates the one standard deviation range). The transfer factor (TF) values were high only in Bomborait soils (TF > 1). Leafy vegetables and juicy fruits (possessing high water content) were found to be more susceptible to TAs contamination. The daily intake of metals (DIA), human health risk index (HRI), and cancer risk demonstrated that the Chitral Valley is at high risk due to TAs contamination, which may pose a threat to the concerned community and ecosystem. The current findings suggest that leafy vegetables and juicy fruits in the study area should be carefully consumed.