TY - JOUR
T1 - Nitrates in drinking water and the risk of death from rectal cancer
T2 - Does hardness in drinking water matter?
AU - Chang, Chih Ching
AU - Chen, Chih Cheng
AU - Wu, Deng Chuang
AU - Yang, Chun Yuh
N1 - Funding Information:
Received 15 April 2010; accepted 28 April 2010. This study was supported by a grant from the National Science Council, Executive Yuan, Taiwan (NSC-97-2314-B-037-006-MY3). Address correspondence to Chun-Yuh Yang, PhD, MPH, Institute of Public Health, College of Health Sciences, Kaohsiung Medical University, 100 Shih-Chuan 1st RD, Kaohsiung, Taiwan 80708. E-mail: chunyuh@kmu.edu.tw
PY - 2010
Y1 - 2010
N2 - The objectives of this study were to (1) examine the relationship between nitrate levels in public water supplies and increased risk of death from rectal cancer and (2) determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the effects of nitrate on development of rectal cancer. A matched case-control study was used to investigate the relationship between the risk of death from rectal cancer and exposure to nitrate in drinking water in Taiwan. All rectal cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth, and year of death. Information on the levels of nitrate-nitrogen (NO3-N), Ca, and Mg in drinking water was collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's NO3-N, Ca, and Mg exposure via drinking water. Relative to individuals whose NO3-N exposure level was 0.38 ppm, the adjusted odds ratio (OR) (95% CI) for rectal cancer occurrence was 1.15 (1.01-1.32) for individuals who resided in municipalities served by drinking water with a NO3-N exposure 0.38 ppm. There was no apparent evidence of an interaction between drinking water NO3-N levels with low Mg intake via drinking water. However, evidence of a significant interaction was noted between drinking-water NO3-N concentrations and Ca intake via drinking water. Our findings showed that the correlation between NO3-N exposure and risk of rectal cancer development was influenced by Ca in drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO3-N exposure and risk of rectal cancer occurrence. Increased knowledge of the mechanistic interaction between Ca and NO3-N in reducing rectal cancer risk will aid in public policymaking and setting threshold standards.
AB - The objectives of this study were to (1) examine the relationship between nitrate levels in public water supplies and increased risk of death from rectal cancer and (2) determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the effects of nitrate on development of rectal cancer. A matched case-control study was used to investigate the relationship between the risk of death from rectal cancer and exposure to nitrate in drinking water in Taiwan. All rectal cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth, and year of death. Information on the levels of nitrate-nitrogen (NO3-N), Ca, and Mg in drinking water was collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's NO3-N, Ca, and Mg exposure via drinking water. Relative to individuals whose NO3-N exposure level was 0.38 ppm, the adjusted odds ratio (OR) (95% CI) for rectal cancer occurrence was 1.15 (1.01-1.32) for individuals who resided in municipalities served by drinking water with a NO3-N exposure 0.38 ppm. There was no apparent evidence of an interaction between drinking water NO3-N levels with low Mg intake via drinking water. However, evidence of a significant interaction was noted between drinking-water NO3-N concentrations and Ca intake via drinking water. Our findings showed that the correlation between NO3-N exposure and risk of rectal cancer development was influenced by Ca in drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO3-N exposure and risk of rectal cancer occurrence. Increased knowledge of the mechanistic interaction between Ca and NO3-N in reducing rectal cancer risk will aid in public policymaking and setting threshold standards.
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U2 - 10.1080/15287394.2010.490178
DO - 10.1080/15287394.2010.490178
M3 - Article
C2 - 20711935
AN - SCOPUS:77955603026
VL - 73
SP - 1337
EP - 1347
JO - Journal of Toxicology and Environmental Health - Part A: Current Issues
JF - Journal of Toxicology and Environmental Health - Part A: Current Issues
SN - 1528-7394
IS - 19
ER -
