Carcinogenic and Non-Carcinogenic Risk Assessment of Heavy Metals in Water Resources of North East of Iran in 2018

Abstract

Introduction: Contamination of water with heavy metals has turned into a health concern, particularly in the developing countries. In this study, concentration of heavy metals and associated carcinogenic and non- carcinogenic risk was investigated in water samples collected from Gonbad-e Kavus, a high-risk area for cancer. Materials and Methods: Samples were collected from Gorgan River, Golestan reservoir and wells around villages with high prevalence in 2018. Samples were analysed through inductively coupled plasma mass spectrometry. After determining the concentration of heavy metals in water samples from different sources, health risk assessment was carried out according to the Environmental Protection Agency.  Results: Arsenic in samples 6-9 was higher than 10 µg/L, calcium and magnesium in sample 5 was higher than 200 mg/L and 150 mg/L respectively, and sodium in all samples was higher than 50 mg/L.  According to the findings, these concentrations were higher than the maximum allowed limit in most water samples. Hazard quotient (HQ) in samples 8 and 9 were associated with arsenic and health risk in sample 1 was related to antimony. Furthermore, since all samples contained high amounts of lithium, water from this area better should not be consumed by children older than one year. Conclusion: Given the high rate of arsenic contamination, consumption of water in the study area could be health threatening for all individuals and is not recommended for children. This highlights the need for taking immediate actions to review the water treatment process and ensure safety of the drinking water in this area.