[Water, sanitation, and hygiene (WASH): a study of Brazilian rural public elementary schools].

This study investigated the lack of access to water, sanitation, and hygiene (WASH) at Brazilian rural public elementary schools through a cross-sectional comparative study of the years 2011 and 2023. The distribution, temporal evolution, and determinant factors of this lack were assessed through descriptive analysis and binomial logistic regression, using the School Census of Basic Education as the main database. The results reveal persistent regional inequalities: the North region had the highest odds ratios for the absence of all WASH services in both years analyzed. Schools located on indigenous lands, with less than 10 students or with high dropout rates and low passing rates, had a greater likelihood of health exclusion. On the municipal level, the high proportion of the rural population and low Municipal Human Development Index - Income stood out as determinants. Despite occasional advances in access to water, setbacks in other services indicate stagnation or the worsening of inequalities. The results reveal that, after more than ten years, rural Brazil is still far from meeting the 4.a.1 target of the Sustainable Development Goals, which stipulates universal access to WASH in the school environment. By revealing the main institutional and regional obstacles, this study contributes to the planning of public policies that are more equitable and sensitive to the specificities of rural areas in Brazil.