Nitrate from Drinking Water and Diet and Bladder Cancer Among Postmenopausal Women in Iowa

Jones, Rena R.; Weyer, Peter J.; DellaValle, Curt T.; Inoue-Choi, Maki; Anderson, Kristin E.; Cantor, Kenneth P.; Krasner, Stuart W.; Robien, Kim; Freeman, Laura E. Beane; Silverman, Debra T.; Ward, Mary H.

doi:10.1289/ehp191

Cited by 109 publications

(82 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the dietary analyses, we estimated hazard ratios for categories of overall dietary nitrate and nitrite as well as nitrite intake from plant, animal, and processed meat sources separately. Dietary nitrate from animal and plant sources was not analyzed separately because most dietary nitrate (median proportion = 97%) was derived from plant sources . We adjusted final dietary models for age, categorical smoking status, total calorie intake and mutually adjusted for either dietary nitrate or nitrite.…”

Section: Methodscontrasting

confidence: 60%

“…We previously described the assessment of contaminants in public water supplies (PWS) and report the key elements herein . Nitrate‐nitrogen (NO 3 ‐N) measured in water samples from municipal water supplies in Iowa were used to calculate annual average NO 3 ‐N (mg/L) levels for each PWS from measurements across the 33‐year historical exposure period (1955–1988).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Ingested nitrate and nitrite, disinfection by‐products, and pancreatic cancer risk in postmenopausal women

Quist

Inoue-Choi

Weyer

et al. 2017

Intl Journal of Cancer

Self Cite

View full text Add to dashboard Cite

Nitrate and nitrite are precursors of N-nitroso compounds (NOC), probable human carcinogens that cause pancreatic tumors in animals. Disinfection by-products (DBP) exposures have also been linked with digestive system cancers, but few studies have evaluated relationships with pancreatic cancer. We investigated the association of pancreatic cancer with these drinking water contaminants and dietary nitrate/nitrite in a cohort of postmenopausal women in Iowa (1986-2011). We used historical monitoring and treatment data to estimate levels of long-term average nitrate and total trihalomethanes (TTHM; the sum of the most prevalent DBP class) and the duration exceeding one-half the maximum contaminant level (>½ MCL; 5 mg/L nitrate-nitrogen, 40 µg/L TTHM) among participants on public water supplies (PWS) >10 years. We estimated dietary nitrate and nitrite intakes using a food frequency questionnaire. We computed hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression and evaluated nitrate interactions with smoking and vitamin C intake. We identified 313 cases among 34,242 women, including 152 with >10 years PWS use (N = 15,710). Multivariable models of average nitrate showed no association with pancreatic cancer (HR = 1.16, 95% CI: 0.51-2.64). Associations with average TTHM levels were also null (HR = 0.70, 95% CI:0.42-1.18). We observed no trend with increasing years of exposure to either contaminant at levels >½ MCL. Positive associations were suggested in the highest dietary nitrite intake from processed meat (HR = 1.66, 95% CI 1.00-2.75;p = 0.05). We found no interactions of nitrate with known modifiers of endogenous NOC formation. Our results suggest that nitrite intake from processed meat may be a risk factor for pancreatic cancer.

show abstract

Section: Methodscontrasting

confidence: 60%

Section: Methodsmentioning

confidence: 99%

Ingested nitrate and nitrite, disinfection by‐products, and pancreatic cancer risk in postmenopausal women

Quist

Inoue-Choi

Weyer

et al. 2017

Intl Journal of Cancer

Self Cite

View full text Add to dashboard Cite

show abstract

“…31 We observed no association between dietary nitrate intake and kidney cancer risk, or for dietary nitrite overall (Table 3). However, a higher risk was evident for the 95 th percentile of dietary nitrite from processed meats (HR p95vs.Q1 =1.8,95%CI:1.1–3.0; p trend =0.54).…”

Section: Resultsmentioning

confidence: 73%

Ingested Nitrate, Disinfection By-products, and Kidney Cancer Risk in Older Women

et al. 2017

Self Cite

View full text Add to dashboard Cite

Background N-nitroso compounds formed endogenously after nitrate/nitrite ingestion are animal renal carcinogens. Previous epidemiologic studies of drinking water nitrate did not evaluate other potentially toxic water contaminants, including the suspected renal carcinogen chloroform. Methods In a cohort of postmenopausal women in Iowa (1986–2010), we used historical measurements to estimate long-term average concentrations of nitrate-nitrogen (NO3-N) and disinfection byproducts (DBP) in public water supplies. For NO3-N and the regulated DBP [total trihalomethanes (THM) and the sum of five haloacetic acids (HAA5)], we estimated the number of years of exposure above one-half the current maximum contaminant level (>½-MCL NO3-N; >5mg/L). Dietary intakes were assessed via food frequency questionnaire. We estimated hazard ratios (HR) and 95% confidence intervals (CI) with Cox models, and evaluated interactions with factors influencing N-nitroso compound formation. Results We identified 125 incident kidney cancers among 15,577 women reporting using water from public supplies >10 years. In multivariable models, risk was higher in the 95th percentile of average NO3-N (HRP95vsQ1=2.3;CI:1.2–4.3;ptrend=0.33) and for any years of exposure >½-MCL; adjustment for total THM did not materially change these associations. There were no independent relationships with total THM, individual THMs chloroform and bromodichloromethane, or with haloacetic acids. Dietary analyses yielded associations with high nitrite intake from processed meats but not nitrate or nitrite overall. We found no interactions. Conclusions Relatively high nitrate levels in public water supplies were associated with increased risk of renal cancer. Our results also suggest that nitrite from processed meat is a renal cancer risk factor.

show abstract

“…While there is a plausible etiological explanation with endogenous nitrosation, epidemiological evidence from studies on humans has been inconclusive [3,4]. However, two recent studies show an association between nitrate in drinking water and cancer, in particular colorectal cancer [6], and bladder cancer [7]. There is also evidence that nitrate in drinking water may be associated with an increased risk of birth defects [8] and other adverse reproductive outcomes [9].…”

Section: Introductionmentioning

confidence: 99%

Nitrate, Nitrite, and Ammonium Variability in Drinking Water Distribution Systems

Schullehner

Stayner

2017

IJERPH

View full text Add to dashboard Cite

Accurate assessments of exposure to nitrate in drinking water is a crucial part of epidemiological studies investigating long-term adverse human health effects. However, since drinking water nitrate measurements are usually collected for regulatory purposes, assumptions on (1) the intra-distribution system variability and (2) short-term (seasonal) concentration variability have to be made. We assess concentration variability in the distribution system of nitrate, nitrite, and ammonium, and seasonal variability in all Danish public waterworks from 2007 to 2016. Nitrate concentrations at the exit of the waterworks are highly correlated with nitrate concentrations within the distribution net or at the consumers’ taps, while nitrite and ammonium concentrations are generally lower within the net compared with the exit of the waterworks due to nitrification. However, nitrification of nitrite and ammonium in the distribution systems only results in a relatively small increase in nitrate concentrations. No seasonal variation for nitrate, nitrite, or ammonium was observed. We conclude that nitrate measurements taken at the exit of the waterworks are suitable to calculate exposures for all consumers connected to that waterworks and that sampling frequencies in the national monitoring programme are sufficient to describe temporal variations in longitudinal studies.

show abstract

Nitrate from Drinking Water and Diet and Bladder Cancer Among Postmenopausal Women in Iowa

Cited by 109 publications

References 45 publications

Ingested nitrate and nitrite, disinfection by‐products, and pancreatic cancer risk in postmenopausal women

Ingested nitrate and nitrite, disinfection by‐products, and pancreatic cancer risk in postmenopausal women

Ingested Nitrate, Disinfection By-products, and Kidney Cancer Risk in Older Women

Nitrate, Nitrite, and Ammonium Variability in Drinking Water Distribution Systems

Contact Info

Product

Resources

About