Chlorination byproducts and nitrate in drinking water and risk for congenital cardiac defects.
Drinking water disinfection byproducts have been associated with an increased risk for congenital defects including cardiac defects. Using Swedish health registers linked to information on municipal drinking water composition, individual data on drinking water characteristics were obtained for 58,669 women. Among the infants born, 753 had a cardiac defect. The risk for a cardiac defect was determined for ground water versus surface water, for different chlorination procedures, and for trihalomethane and nitrate concentrations. Ground water was associated with an increased risk for cardiac defect when crude rates were analyzed but after suitable adjustments this excess rate was found to be determined by chlorination procedures including chlorine dioxide. Chlorine dioxide appears itself as an independent risk factor for cardiac defects (adjusted odds ratio 1.61 (95%CI 1.00-2.59)). The risk for cardiac defects increased with increasing trihalomethane concentrations (P=0.0005). There was an indicated but statistically nonsignificant excess risk associated with nitrate concentration. The individual risk for congenital cardiac defect caused by chlorine dioxide and trihalomethanes is small but as a large population is exposed to public drinking water, the attributable risk for cardiac defects may not be negligible.
Division of Obstetrics and Gynaecology, Department of Health and Environment, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden.
Marie I
MI
Cedergren
Anders J
AJ
Selbing
Owe
O
Löfman
Bengt A J
BA
Källen
D000328:Adult; D017606:Chlorine Compounds / Q000009:adverse effects*; D019551:Dental Disinfectants / Q000009:adverse effects*; D004202:Disinfectants / Q000009:adverse effects* / Q000737:chemistry; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D009566:Nitrates / Q000009:adverse effects*; D016017:Odds Ratio; D010087:Oxides / Q000009:adverse effects*; D011247:Pregnancy; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D013548:Sweden; D022882:Trihalomethanes / Q000009:adverse effects*; D014873:Water Pollutants / Q000009:adverse effects; D018508:Water Purification; D014881:Water Supply
D017606:Chlorine Compounds; D019551:Dental Disinfectants; D004202:Disinfectants; D009566:Nitrates; D010087:Oxides; D022882:Trihalomethanes; D014873:Water Pollutants; C025109:chlorine dioxide