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This study examined the relationship between proximity to brick kilns and child health outcomes in Bangladesh by analyzing satellite data on 6,978 kilns and health data from 23,357 children under five years old. Contrary to expectations, researchers found no association between living near brick kilns and elevated blood lead levels in children, and only weak, inconsistent associations with respiratory symptoms that did not align with peak firing seasons. The findings suggest that observed health patterns may reflect geographical confounding rather than direct effects of kiln emissions.
Why it matters
Brick kilns are major sources of air pollution in Bangladesh and similar South Asian countries, affecting millions of children. These findings challenge assumptions about their health impacts and suggest that policy interventions may need more localized assessment, as health effects may be concentrated within 1-2 km of kilns rather than the 5 km radius studied here.
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⚠️ Preprint – Noch nicht peer-reviewed
Dieser Artikel wurde noch nicht von unabhängigen Experten begutachtet. Die Ergebnisse sind vorläufig und sollten mit Vorsicht interpretiert werden.
Background: Brick kilns are a major source of air pollution in Bangladesh. Their effects on child respiratory health and lead exposure have not been studied nationally with blood measures. Methods: We linked a 2018 to 2019 satellite map of 6,978 kilns to the 3,149 displaced clusters of the Bangladesh Multiple Indicator Cluster Survey 2025. Exposure was the number of kilns within 5 km. Outcomes were cough and acute respiratory infection (ARI) symptoms in 23,357 children under 5 years, and venous blood lead in 10,622 children aged 12 to 59 months. We fitted survey-weighted modified Poisson models with district fixed effects. Diarrhoea and interview timing relative to the firing season served as negative controls. Findings: Three in four children (75.4%, 95% CI 73.6 to 77.1) lived within 5 km of a kiln, and 20.3% (18.7 to 22.0) had ten or more. Exposure rose with wealth. Compared with no kiln, ten or more kilns were not associated with cough (adjusted prevalence ratio [PR] 1.05, 0.96 to 1.16), ARI symptoms (1.21, 0.90 to 1.62) or blood lead of 5 microgram/dL or more (0.94, 0.85 to 1.03; crude PR 1.27, 1.14 to 1.41). Per 10 kilns, the ARI PR was 1.11 (1.01 to 1.21), but a spline showed no association (P=0.153). Cough was not associated with kiln density at the peak of firing (PR per 10 kilns 1.00, 0.96 to 1.05) but was in May and June (1.10, 1.04 to 1.17). The lead result held in all sensitivity analyses. Interpretation: At survey resolution, living among more kilns was not linked to blood lead. Weak respiratory associations, absent at peak firing, fit confounding by place better than an acute effect of kiln smoke. Studies with exact locations should measure effects within 1 to 2 km of kilns.