title: Overview of Disinfection By-products and Associated Health Effects.
abstract: The presence of chemical compounds formed as disinfection by-products (DBPs) is widespread in developed countries, and virtually whole populations are exposed to these chemicals through ingestion, inhalation, or dermal absorption from drinking water and swimming pools. Epidemiological evidence has shown a consistent association between long-term exposure to trihalomethanes and the risk of bladder cancer, although the causal nature of the association is not conclusive. Evidence concerning other cancer sites is insufficient or mixed. Numerous studies have evaluated reproductive implications, including sperm quality, time to pregnancy, menstrual cycle, and pregnancy outcomes such as fetal loss, fetal growth, preterm delivery, and congenital malformation. The body of evidence suggests only minor effects from high exposure during pregnancy on fetal growth indices such as small for gestational age (SGA) at birth. Populations highly exposed to swimming pools such as pool workers and professional swimmers show a higher prevalence of respiratory symptoms and asthma, respectively, although the direction of the association, and thus causality, is not clear among professional swimmers. The risk of asthma, wheezing, eczema, and other respiratory outcomes among children attending swimming pools has been the object of extensive research. Early studies suggested a positive association, while subsequent larger studies found no correlations or showed a protective association. Future research should develop methods to evaluate the effects of the DBP mixture and the interaction with personal characteristics (e.g., genetics, lifestyle), clarify the association between swimming pools and respiratory health, evaluate the occurrence of DBPs in low- and middle-income countries, and evaluate outcomes suggested by animal studies that have not been considered in epidemiological investigations.
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona Biomedical Research Park (PRBB), Doctor Aiguader 88, 08003, Barcelona, Spain, cvillanueva@creal.cat.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Villanueva
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Cordier
authors.forename: Laia
authors.initials: L
authors.lastname: Font-Ribera
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Salas
authors.forename: Patrick
authors.initials: P
authors.lastname: Levallois
mesh_terms: D000818:Animals; D001249:Asthma / Q000139:chemically induced; D004202:Disinfectants / Q000009:adverse effects* / Q000032:analysis; D060766:Drinking Water / Q000737:chemistry*; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000139:chemically induced; D011634:Public Health; D012140:Respiratory Tract Diseases / Q000139:chemically induced; D013551:Swimming Pools; D022882:Trihalomethanes / Q000009:adverse effects / Q000737:chemistry
chemical_list: D004202:Disinfectants; D060766:Drinking Water; D022882:Trihalomethanes