Spatial distribution, occurrence, and health risk assessment of nitrate, fluoride, and arsenic in Bam groundwater resource, Iran

Evidence shows that exposure to high levels of arsenic, fluoride, and nitrate may be contributing to adverse hygienic effects. This work was carried out to detect the concentration of arsenic (As), fluoride (F-), and nitrate (NO3) in the groundwater resource of Bam, southeastern Iran and approximate their health risk to citizenships. The GIS-mapping of As, F-, and NO3 concentrations was accomplished. As, F-, and NO3 concentrations in studied drinking water samples have been ranged from 9.26 to 14.65 mu g/L, 0.91-1.12 mg/L, and 8.50-10.85 mg/L, respectively. Based on results, all measured concentrations of F- and NO3 were lower than the WHO standard value, while As levels were higher than the allowed value. The acquired findings revealed that the mean risk of As is 5.372 for oral hazard quotient (HQ) and 1.407 for dermal one. For F-, HQ values for children were computed above one for study areas, while all HQ values for adults were below one. The values of dermal and oral HQ for both groups obtained >1 for NO3. Among studied contaminants, the carcinogenic risk (CR) values of As was more than one. The results showed that the carcinogenicity ratio of 'children to adults' is equal to 3.8 for As and 2.33 for NO3. For all examined pollutants, the health risks of dermal exposure were less than that of oral. The levels of non-cancer and cancer risk for children were greater than those for adults. The highest non-carcinogenic risk in study areas was related to As. This research proposes that any attempt to mitigate the arsenic of the Bam citizenships must consider the health risk of As exposure from potable water.

Automated summary

The study detected concentrations of arsenic, fluoride, and nitrate in groundwater of Bam, Iran, with arsenic posing the highest health risk. Children had higher health risks from fluoride, while adults had lower risks. Dermal exposure risks were greater than oral exposure risks for all contaminants, with arsenic having the highest non-carcinogenic risk in the study areas.