Long-Term Cognitive Health Outcomes Among Villagers with Improved Sanitation Practices in India

Poor sanitation has large negative impacts on environmental quality, health, and well-being. Sanitation infrastructure is particularly lacking in India, where in 2011, 66% of households practiced open defecation, which is a major contributor to the global burden of disease. Previous studies have shown that access to improved sanitation lowers the risk of fecal exposure, which in turn decreases the rate of infection and illness, thus improving cognitive development. In this study, we explored the extent to which access to improved sanitation in early childhood can affect long-term cognitive development. We build on literature linking child health improvements to cognitive development and labor market outcomes and show that improvements in sanitation coverage can have large human capital returns.

We assessed individuals ten years after they had participated in an experimental sanitation campaign in rural Odisha, India and found that higher rates of village-level latrine coverage in one’s childhood have large long-term positive impacts on cognitive development. These results are largely concentrated in girls, and we present the first evidence of cognitive returns from sanitation improvement disaggregated by gender. Potential mechanisms that could explain the differences in outcomes between genders include differences in how boys and girls interact with the village, boys receiving more early-life health investments overall, and potential differences in educational attainment between boys and girls.

Our findings suggest that widespread open defecation practices in India have significant human capital costs, given the links between cognitive development and labor market outcomes. While previous analyses showed that latrines are highly cost-effective investments, they may have understated the benefits of improved sanitation by not accounting for long-term potential human capital gains, which make latrines an even more attractive investment. While the Indian government is devoting large amounts of resources to make India ‘‘open defecation free” through its Swachh Bharat Mission, previous national efforts (such as the Total Sanitation Campaign) proved unsuccessful in significantly changing sanitation practices. Thus, more research investigating barriers to latrine adoption and sustained use is critical if these long-term human capital benefits are to be realized on a large scale.

The intervention took place within the Bhadrak district, Odisha, India. In total, 40 villages were selected to participate in the study. Out of those 40, half were randomly assigned to receive the community-led total sanitation (CLTS) treatment, which is an intensive community-level behavioral intervention to increase the adoption of individual household latrines. The treatment group had a 28.7% higher rate of latrine adoption than the control groups one year after the intervention. Additionally, children in treatment villages showed significant health improvements, suggesting that the CLTS intervention both increased latrine adoption and improved child health outcomes in the short term. To measure long-term human capital impacts of early-life exposure to an improved sanitation environment, children completed an abbreviated version of the Raven’s Colored Progressive Matrices (RCPM) test ten years after the intervention. We find that children who belonged to a village with higher latrine coverage scored significantly higher on a cognitive test measuring analytic ability ten years later.

Additional findings included that sanitation improvements in population-dense areas lead to larger cognitive gains for boys, while similar improvements in less population-dense areas lead to larger cognitive gains for girls. We did not find that the treatment impacted short-term school enrollment, though we did not collect data on short-term school attendance where there might have been an impact. Similarly, we did not find that the treatment had an impact on long-term school enrollment or attendance. Additional research is needed to explore the effect of population density.





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