Human health risks of heavy metals in water and vegetables: a deterministic and probabilistic study in...

There is a growing global concern about the presence of heavy metals in the environment due to their detrimental effects on human health. These metals are eminent poisons with carcinogenic features that can harm organs such as brain, kidney, lungs, etc. This study investigated the human health risks associated with toxic metals such as lead (Pb), nickel (Ni), cadmium (Cd), chromium (Cr), and copper (Cu) in drinking water and vegetable sources from Northern Areas, Gilgit-Baltistan, Pakistan. A total of 68 representative drinking water and the most commonly consumed green leafy vegetable samples were collected from Nagar and Hunza district. In this study, significant carcinogenic and non-carcinogenic risks were identified, particularly in children, using deterministic and Monte Carlo simulation methods in addition to spatial analysis, correlation, principal component analysis, and hierarchical clustering. Hazard quotient (HQ) oral > 1 for Cr, Ni, Cd, and Pb in the water and vegetables of the Hunza district; HQ > 1 for all heavy metals except for Mn in vegetables from Nagar in children. HQ > 1 for Mn and Cu in the water and vegetables of Hunza district, likewise Mn exceeded the HQ limit in the water and vegetables in adults from the Nagar region. Lifetime cancer risk (LCR) oral > 1E-4 for all toxic metals in children across all district samples. Similarly, Cd and Pb exceeded the LCR for adults from both districts. LCR_dermal > 1E-4 for Ni, Cr, and Pb in children of Hunza, suggesting more vulnerability to developing cancer over exposure to toxic metals. The level of HQ and LCR via inhalation, demonstrating no adverse health risks for children and adults. Furthermore, the Monte Carlo Simulation was applied to assess the probability of potential health risks, which indicated a significantly higher risk for children than for adults. These findings underline the urgent need for mitigation strategies to reduce heavy metal exposure in Nagar and Hunza regions.