title: Estimated effects of disinfection by-products on birth weight in a population served by a single water utility.
abstract: Research has suggested that trihalomethane exposures during pregnancy might impair fetal growth. Most epidemiologic studies, however, relied on relatively crude exposure assessment methods and did not examine racial/ethnic subgroups. During 1999-2001, vital records data were obtained for a large, racially diverse population residing in 27 Massachusetts communities that received drinking water from a single public utility. The water system was monitored weekly for trihalomethanes and, system-wide, it maintained geographically stable total trihalomethane levels during the study period. The authors examined the effects of trimester-specific and pregnancy average exposures to total trihalomethane in drinking water on term low birth weight in all singleton births. A high average total trihalomethane exposure (> or = 70 microg/liter) during the second trimester increased the risk of term low birth weight (odds ratio = 1.50, 95% confidence interval (CI): 1.07, 2.10). The estimated risk increase for Caucasians during the second trimester was 37% (95% CI: 0.80, 2.36), while for all minority women combined (i.e., African Americans, Hispanics, and Asians) it was 60% (95% CI: 1.03, 2.47). The study data suggest that high levels (> or = 70 microg/liter) of trihalomethanes experienced during the second trimester and pregnancy overall may affect fetal growth.
authors.affiliation: Environmental Science and Engineering Program, Department of Environmental Health Sciences, School of Public Health, University of California, Los Angeles, CA, USA. myta_3@yahoo.com
authors.forename: C
authors.initials: C
authors.lastname: Lewis
authors.forename: I H
authors.initials: IH
authors.lastname: Suffet
authors.forename: B
authors.initials: B
authors.lastname: Ritz
mesh_terms: D000328:Adult; D004202:Disinfectants / Q000737:chemistry / Q000633:toxicity*; D016021:Epidemiologic Studies; D005260:Female; D005317:Fetal Growth Retardation / Q000139:chemically induced; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008404:Massachusetts; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000187:drug effects; D017150:Public Sector; D018570:Risk Assessment; D012307:Risk Factors; D022882:Trihalomethanes / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification
chemical_list: D004202:Disinfectants; D022882:Trihalomethanes