Nitrate in Public Water Supplies and the Risk of Colon and Rectum Cancers

Abstract

Our analyses suggest that any increased risk of colon cancer associated with nitrate in public water supplies might occur only among susceptible subpopulations.

Nitrogen-nitrate exposure from drinking water and colorectal cancer risk for rural women in Wisconsin, USA

“…A case-control study also assigned a yearly average nitrate level computed from respondents' municipal water supply from 1960 to year of cancer diagnosis for cases (1986 or 1987) Slovakia to high nitrate levels (Gulis et al 2002). The mean concentration of nitrate-nitrogen exposure in the highest category from these studies was .2.46 ppm in the inverse association study (Weyer et al 2001), .2.46 ppm and .5 ppm in the null finding study (Weyer et al 2001) and .5 ppm and 20-50 ppm in the positive association studies (Gulis et al 2002;De Roos et al 2003). In contrast to these three epidemiologic study, our study used randomly sampled individual well water data.…”

“…Nitrogen is the most pervasive groundwater contaminant in the United States (USGS 1999) and in Wisconsin, (Vanden Brook et al 2002) yet few epidemiologic studies have evaluated colorectal cancer risk. Drinking water contaminated with nitrate-nitrogen is a plausible risk factor given the colon's direct exposure to waterborne contaminates (Weyer et al 2001;Gulis et al 2002;De Roos et al 2003). The state of Wisconsin and federal laws set the maximum allowable level of nitrate-nitrogen in public drinking water at 10 parts per million (ppm), although no regulation of private drinking water exists.…”

Fallow replacement and alternative nitrogen management for reducing nitrate leaching in a semiarid region

“…Puckett et al (2011) showed that average nitrate-N concentrations in 424 shallow unconfined groundwater wells across the United States increased from \2 mg L -1 in the early 1940s to 15 mg L -1 by 2003. Nitrate-N concentrations above the Environmental Protection Agency's (EPA's) primary drinking water standard of 10 mg L -1 have been linked to adverse health effects such as methemoglobinemia (Knobeloch et al 2000;Fewtrell 2004) and cancer (De Roos et al 2003;Ward et al 2005). Beyond health concerns, nitrate leaching can result in economic losses for agricultural producers (Janzen et al 2003;Miao et al 2014), making greater N use efficiency (NUE)-conceived here as the ratio of crop N uptake to plant available N-a promising shared goal for sound environmental stewardship and economic sustainability.…”

An Innovative Nitrate Pollution Index and Multivariate Statistical Investigations of Groundwater Chemical Quality of Umm Rijam Aquifer (B4), North Yarmouk River Basin, Jordan

“…In strong oxidizing groundwater, nitrate the stable form of nitrogen, and it moves with no or little transformation and little or no retardation (Freeze and Cherry, 1979). Chronic exposure to high nitrate concentration in drinking water has been linked to adverse health effects on humans, such as colon and rectum cancers, methemoglobinemia in infants, and nonHodgkin's lymphoma (Ward et al, 1996;Knobeloch et al, 2000;De Roos et al, 2003). Groundwater with nitrate concentration exceeding the threshold of 20 mg/L as NO 3 -is considered contaminated due to human activities (referred to as human affected value, HAV) (Spalding and Exner, 1993).…”