Metal exposure and reproductive disorders in indigenous communities living along the Pilcomayo River, Bolivia

The Pilcomayo River is polluted by tailings and effluents from upstream mining activities, which contain high levels of metals. The Weenhayek live along this river and are likely to have elevated exposure. To assess whether the Weenhayek have increased risk of reproductive and developmental disorders related to elevated metal exposure in comparison with a reference population. We assessed reproductive and developmental outcomes, i.e. fertility, fetal loss, congenital anomalies, and walking onset by means of structured interviews. We sampled hair, water and fish to assess the relative exposure of the Weenhayek. Samples were analyzed for Pb and Cd with ICP-MS techniques. The Weenhayek communities studied had a higher prevalence of small families (OR 2.7, 95% CI 1.3–6.0) and delayed walking onset (OR 2.7, 95% CI 1.4–5.1) than the reference population. Median Pb levels in Weenhayek hair were 2–5 times higher than in the reference population, while Cd levels were not elevated. In water and fish, both Pb and Cd levels were increased in the Weenhayek area. We found indications for increased risks of small families and delayed walking onset among the Weenhayek living along the Pilcomayo River. Lactants form a high risk group for lead exposure. ► We assessed selected disorders and metal exposure in two comparable populations. ► Risks of small families and delayed walking onset were increased in the population with elevated lead levels in hair. ► The population with increased risks lives along a river with increased lead and cadmium levels in water and fish.