title: Chemical quality of tap water in Madrid: multicase control cancer study in Spain (MCC-Spain).
abstract: Chronic consumption of water, which contains contaminants, may give rise to adverse health effects. The Madrid region, covered by the population-based multicase-control (MCC-Spain) study, includes two drinking water supply areas. The different sources of the water, coupled together with the possible differences in water management, mean that there may be differences in drinking water quality. In the context of the MCC study, our aims were to describe contaminant concentrations in tap water drawn from various sampling points distributed around the region, assess these concentrations by reference to guideline values and study possible differences between the two supply areas. Tap water samples were collected from 34 sampling points in 7 towns in the Madrid region (19-29 April 2010), and 23 contaminants (metals, nitrates, disinfection by-product and Mutagen X levels) were quantified. We undertook a descriptive analysis of the contaminant concentrations in the water and compared them between the two water supply areas (Wilcoxon test). We created maps representing the distribution of the concentrations observed at water sampling points and assessed the correlations (Spearman's coefficient) between the different parameters measured. The concentrations of the contaminants were below guideline values. There were differences between the two supply areas in concentration of nitrates (p value = 0.0051) and certain disinfection by-products. While there were positive correlations (rho >0.70) among some disinfection by-products, no correlations were found in metals or nitrates. The differences in nitrate levels could be linked to differences in farming/industrial activities in the catchment areas and in disinfection by-products might be related to the existence of different treatment systems or bromine content in source waters.
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain. pfernandezn@isciii.es.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain. pfernandezn@isciii.es.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain. pfernandezn@isciii.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fernández-Navarro
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.|Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Villanueva
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: García-Pérez
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Boldo
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Laboratory of Public Health of Gipuzkoa, Avda. de Navarra, 4, 20013, Donostia-San Sebastián, Spain.|Biodonostia Health Research Institute, San Sebastian, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Goñi-Irigoyen
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Laboratory of Public Health of Gipuzkoa, Avda. de Navarra, 4, 20013, Donostia-San Sebastián, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Ulibarrena
authors.affiliation: National Institute for Health and Welfare (THL), Chemicals and Health Unit, P.O. Box 95, 70701, Kuopio, FI, Finland.
authors.forename: Panu
authors.initials: P
authors.lastname: Rantakokko
authors.affiliation: Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Departamento de Medicina Preventiva y Salud Pública, Universidad Autónoma de Madrid, IdiPaz, Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: García-Esquinas
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pérez-Gómez
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Pollán
authors.affiliation: Cancer and Environmental Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, Avda. Monforte de Lemos, 5, 28029, Madrid, Spain.|Consortium for Biomedical Research in Epidemiology and Public Health (CIBER en Epidemiología y Salud Pública-CIBERESP), Madrid, Spain.|Cancer Epidemiology Research Group, Oncology and Hematology Area, IIS Puerta de Hierro (IDIPHIM), Madrid, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Aragonés
mesh_terms: D004203:Disinfection; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology*; D013030:Spain / Q000453:epidemiology; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water
keywords: Disinfection by-products; MCC-Spain; Madrid; Nitrates; Tap water; Water pollutants