title: Assessing exposure and health consequences of chemicals in drinking water: current state of knowledge and research needs.
abstract: BACKGROUND
  Safe drinking water is essential for well-being. Although microbiological contamination remains the largest cause of water-related morbidity and mortality globally, chemicals in water supplies may also cause disease, and evidence of the human health consequences is limited or lacking for many of them.
  
  
  OBJECTIVE
  We aimed to summarize the state of knowledge, identify gaps in understanding, and provide recommendations for epidemiological research relating to chemicals occurring in drinking water.
  
  
  CONCLUSIONS
  Assessing exposure and the health consequences of chemicals in drinking water is challenging. Exposures are typically at low concentrations, measurements in water are frequently insufficient, chemicals are present in mixtures, exposure periods are usually long, multiple exposure routes may be involved, and valid biomarkers reflecting the relevant exposure period are scarce. In addition, the magnitude of the relative risks tends to be small.
  
  
  CONCLUSIONS
  Research should include well-designed epidemiological studies covering regions with contrasting contaminant levels and sufficient sample size; comprehensive evaluation of contaminant occurrence in combination with bioassays integrating the effect of complex mixtures; sufficient numbers of measurements in water to evaluate geographical and temporal variability; detailed information on personal habits resulting in exposure (e.g., ingestion, showering, swimming, diet); collection of biological samples to measure relevant biomarkers; and advanced statistical models to estimate exposure and relative risks, considering methods to address measurement error. Last, the incorporation of molecular markers of early biological effects and genetic susceptibility is essential to understand the mechanisms of action. There is a particular knowledge gap and need to evaluate human exposure and the risks of a wide range of emerging contaminants.
  
  
  BACKGROUND
  Villanueva CM, Kogevinas M, Cordier S, Templeton MR, Vermeulen R, Nuckols JR, Nieuwenhuijsen MJ, Levallois P. 2014. Assessing exposure and health consequences of chemicals in drinking water: current state of knowledge and research needs. Environ Health Perspect 122:213–221; http://dx.doi.org/10.1289/ehp.1206229
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Villanueva
authors.forename: Manolis
authors.initials: M
authors.lastname: Kogevinas
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Cordier
authors.forename: Michael R
authors.initials: MR
authors.lastname: Templeton
authors.forename: Roel
authors.initials: R
authors.lastname: Vermeulen
authors.forename: John R
authors.initials: JR
authors.lastname: Nuckols
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
authors.forename: Patrick
authors.initials: P
authors.lastname: Levallois
mesh_terms: D060766:Drinking Water / Q000009:adverse effects / Q000032:analysis*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D006801:Humans; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000009:adverse effects / Q000032:analysis*
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical