[en] The Matanza River Basin, in Argentina, is the site of the most notorius environmental problem in the country, with high levels of organic contamination from the discharge of untreated sewage and toxic chemicals, such as hydrocarbons and heavy metals, from petrochemical factories, tanneries, and refrigerators. Almost one million socially vulnerable people who are exposed to environmental threats live in the so-called "emerging development zones (urbanizaciones emergentes, or UREM)." This study describes the methodology for drawing an Environmental Health Risk Map (MaRSA) by weighting environmental health determinants (threats and vulnerabilities),in order to characterize the 593 UREM in the Matanza River Basin according to their risk level (very high, high, moderate, low, and very low) and to prioritize the taking of evaluation and management actions. Fifty variables were selected from secondary sources, and prioritization factors and a weighting system interrelating the former by means of the application of the Analytical Hierarchy Process (AHP) were established. Out of the 593 UREM, 71 were classified as being at very high risk (where 170 977 people live), 138 at high risk, 136 at moderate risk, 139 at low risk, and 109 at very low risk.High-risk Zand very-high-risk UREM were selected as a priority to under go Comprehensive Assessments of the Environmental Health in Risk Areas by conducting surveys of households, homes and people and toxicological evaluations of the soil and water and the biomarkers of human exposure to toxic chemicals in each UREM, while identifying and implementing management mechanisms to minimize the risks.

[pt] A bacia Matanza-Riachuelo, na Argentina, é o problema ambiental mais visível do país, com elevados níveis de contaminação orgânica proveniente da descarga de águas residuais não tratadas e compostos químicos tóxicos, tais como hidrocarbonetos e metais pesados, provenientes da indústria petroquímica, da indústria de curtumes e frigoríficos. Nas designadas "urbanizações emergentes (UREM)" reside quase um milhão de pessoas socialmente vulneráveis e expostas a ameaças ambientais. Este trabalho descreve a metodologia para a construção de um mapa de Risco Sanitário Ambiental (MaRSA) ponderando determinantes ambientais de saúde (ameaças e vulnerabilidades), para caracterizar as 593 UREM identificadas na bacia Matanza-Riachuelo de acordo com risco (muito alto, alto, moderado, baixo e muito baixo) e priorizar a implementação de ações de avaliação-gestão. Foram selecionadas 50 variáveis de fontes secundárias e foram estabelecidos fatores de priorização e um sistema de ponderação relacionando-os entre si, utilizando o método do Processo Analítico Hierárquico. Das 593 UREM, 71 foram classificadas como de risco muito alto (onde vivem 170 977 pessoas), 138 com risco alto, risco moderado 136, 139 risco baixo e 109 como risco muito baixo.As UREM com risco alto e muito alto, foram selecionadas prioritariamente para realizar Avaliações Integrais de Saúde Ambiental em Áreas de Risco, através de questionários por edifício, casa e pessoa e através de avaliação toxicológica do solo e da água, e biomarcadores de exposição humana a agentes químicos tóxicos em cada UREM, concomitantemente foram identificados e implementados os mecanismos de gestão para minimizar os riscos.