Integrating QMRA, community perception and geospatial analysis to assess drinking water risks in rural communities of the Brazilian Federal District

ABSTRACT Flowchart detailing four phases: monitoring E. coli in rural water; QMRA showing risks exceed WHO limits; interviews revealing residents' unawareness of risks; and thematic maps identifying fecal contamination sources. This study assessed microbial health risks associated with drinking water consumption in rural areas of the Brazilian Federal District by integrating Quantitative Microbial Risk Assessment (QMRA), community perception surveys, water quality monitoring, and geospatial environmental analysis. QMRA was applied to estimate infection risks from Escherichia coli O157:H7 in water supply sources used by two rural communities. Water quality monitoring revealed noncompliance with potability standards in all seven analyzed sources. Health risk estimates indicated infection probabilities above U.S. Environmental Protection Agency benchmarks in two sources, while Disability-Adjusted Life Years (DALY) exceeded World Health Organization reference values in four sources, implying elevated risks of waterborne diseases. Semi-structured interviews revealed that most residents were unaware of microbial health risks, with perceptions of water quality perception primarily based on organoleptic characteristics. Integration of interview data with geospatial analysis enabled the identification of potential contamination pathways, including wildlife fecal input in surface water sources and sewage effluent infiltration in shallow wells. The integrated approach supports risk-based prioritization of interventions, highlighting the need for systematic water sources monitoring, health risk assessment, environmental education, sanitation infrastructure, treatment, and management solutions by public authorities to ensure safe drinking water in rural communities.