The risk of cancer as a result of elevated levels of nitrate in drinking water and vegetables in Central India

Abstract

The objective of the present study was to determine the effect of nitrates on the incidence of gastrointestinal (GI) cancer development. Nitrate converted to nitrite under reducing conditions of gut results in the formation of N-nitrosamines which are linked to an increased gastric cancer risk. A population of 234 individuals with 78 cases of GI cancer and 156 controls residing at urban and rural settings in Nagpur and Bhandara districts of India were studied for 2 years using a case-control study. A detailed survey of 16 predictor variables using Formhub software was carried out. Nitrate concentrations in vegetables and primary drinking water supplies were measured. The logistic regression model showed that nitrate was statistically significant in predicting increasing risk of cancer when potential confounders were kept at base level (P value of 0.001 nitrate in drinking water; 0.003 for nitrate in vegetable) at P < 0.01. Exposure to nitrate in drinking water at >45 mg/L level of nitrate was associated with a higher risk of GI cancers. Analysis suggests that nitrate concentration in drinking water was found statistically significant in predicting cancer risk with an odds ratio of 1.20.

Physicochemical and microbiological quality of the public water supply in 38 cities from the midwest region of the State of São Paulo, Brazil

“…In elevated concentrations, they can cause a disease called child methaemoglobin, lethal for children, once when in the bloodstream, nitrates are reduced to nitrite, competing with iron for the free oxygen, turning the blood blue (WHO ). In the body, nitrates can also react with amines and amides by nitrosation to form N‐nitrous compounds, which are proven carcinogens (Taneja et al., ).…”

“…Nitrate is the last oxidation phase of organic matter, and therefore, its presence in water is attributed to contamination from agricultural, industrial, and/or urban activities, especially related to animal manure, nitrogen fertilizers, Research Article domestic and industrial sewage, and dumps residues (Taneja, Labhasetwar, Nagarnaik, & Ensink, 2017). In Batman, Turkey, high concentrations of nitrate were reported in groundwater samples collected from areas where agriculture and livestock activities are common (Nalbantcilar & Pinarkara, 2016).…”

Drinking Water Nitrate and Human Health: An Updated Review

“…Nitrate concentrations in groundwater were reported for Morocco, Niger, Nigeria, Senegal, India-Pakistan, Japan, Lebanon, Philippines and Turkey with maximum levels in Senegal (median 42.9 mg/L NO 3 -N) [ 5 ]. In India, nitrate in drinking water supplies is particularly high in rural areas, where average levels have been reported to be 45.7 mg/L NO 3 [ 27 , 28 ] and 66.6 mg/L NO 3 [ 28 ]; maximum levels in drinking water exceeded 100 mg/L NO 3 in several regions [ 27 , 29 ]. Extremely high levels of nitrate have been reported in The Gaza Strip, where nitrate reached concentrations of 500 mg/L NO 3 in some areas, and more than 50% of public-supply wells had nitrate concentrations above 45 mg/L NO 3 [ 30 ].…”

Association Between Nitrite and Nitrate Intake and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis

“…The remaining 62 studies underwent full-text evaluations; 38 of these were excluded for not assigning nitrite or nitrate as exposure markers (n=21), for reporting the sample population (n=12), or for being a systematic review (n=5). Ultimately, 18 case-control studies and 6 cohort studies were included in the final quantitative meta-analysis [22–45]. No additional eligible studies were found in the manual search of the references of retrieved studies.…”