1 Centro de Hemodiálisis, San Salvador, El Salvador Emergency Social Fund for Health of Tierra Blanca, Tierra Blanca, El Salvador.
2 Section of Occupational and Environmental Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Goteborg, Sweden.
3 Faculty of Chemistry and Pharmacy, Universidad de San Carlos, Guatemala, Guatemala.
4 Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA.
5 Regional Institute for Studies on Toxic Substances (IRET), Program on Health, Work and Environment (SALTRA), Universidad Nacional, Heredia, Costa Rica.
6 Research Department, Cardiovascular Surgery Unit, Guatemala, Guatemala Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
7 Division of Nephrology, Department of Medicine, Instituto Nacional de Cardiologia Ignacio Chavez, Mexico city, Mexico.
8 Research Center on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), León, Nicaragua Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
9 Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
10 Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
11 Department of Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico city, Mexico.