Field Evaluation of Nitrate Distribution in Groundwater at Lahijan Landfill: Challenges and Solutions

The main purpose of this article is to investigate the issue of human health due to the continuous consumption of nitrate-contaminated underground water among people of different age groups in the vicinity of Lahijan depot. Therefore, in this study, 34 groundwater samples were collected during the wet (November) and dry (September) seasons, and the main ions were analyzed in the laboratory. Nitrate concentration in the wet season varied from 18 to 30 mg/L with an average of 24.2 mg/L and in the dry season from 8 to 24 mg/L with an average of 14.5 mg/L. The amount of NPI nitrogen pollution index showed that in the wet season, 23% of the samples are healthy and 77% of the sample locations have low pollution, and in the dry season, 82% of the samples are healthy and 18% of the samples have low pollution. The noncarcinogenic risk assessment model showed that health issues are among different age groups, including infants, children, youth, adults, and the elderly. The results of the carcinogenic risk showed that in the wet season, 65% of the underground water samples and in the dry season, 18% of the samples are unsuitable for drinking by the age group of 6 to 12 months. Identified sources of nitrates include nitrate sources found in the study area, anthropogenic activities such as Lahijan landfill and village residents' waste. Therefore, periodic water inspection, health check-up and common treatment plant in rural areas are corrective measures that should be taken to reduce the severe effects of nitrate-contaminated drinking water in the study area.