Assessment of Human Health Risk from Chromium in Drinking Water in the Northeast of Iran Using the Monte Carlo Simulation

Background: Despite technological advancements, heavy metal concentrations in water sources remain above the safe limits set by regulatory standards worldwide. Contaminated drinking water containing heavy metals poses significant public health concerns globally. Objectives: This study aims to examine the non-carcinogenic and carcinogenic risks for adults and children exposed to chromium (Cr) in drinking water through ingestion and dermal pathways. Methods: Health risk assessments were conducted on 60 samples collected from ten active wells and ten stations within the drinking water distribution network sections in Fariman, Iran. The Superfund risk assessment model from the US Environmental Protection Agency (EPA) was employed to evaluate health risks. Crystal Ball software was used to perform Monte Carlo simulations and sensitivity analyses to reduce uncertainties and assess the impact of each variable on the risk assessment results. Results: The hazard quotient (HQ) values for Cr from ingestion pathways exceeded the safety level threshold (HQ > 1) for both adults and children in all sampling sites, while for dermal exposure, the HQ was lower than the safe limit for both populations. The mean cancer risk (CR) values for children and adults via ingestion were 4.58 × 10-4 and 7.9 × 10-5, respectively. However, the CR associated with dermal exposure for both groups was deemed negligible. Conclusions: The health risk of Cr exposure from drinking water exceeds the acceptable safety level for children and adults. This indicates that drinking water is the primary source of Cr exposure for residents in Fariman. It is essential to implement more control measures and suitable purification systems to reduce Cr levels in the water supply in Fariman.