Is living in a region with high groundwater arsenic contamination associated with adverse reproductive health outcomes? An analysis using nationally representative data from India.

BACKGROUND

Exposure to groundwater arsenic via drinking water is common in certain geographies, such as parts of India, and causes a range of negative health effects, potentially including adverse reproductive health outcomes.

METHODS

We conducted an ecological analysis of self-reported rates of stillbirth, recurrent pregnancy loss, and infertility in relation to groundwater arsenic levels in India. We used a gridded, modeled dataset of the probability of groundwater arsenic exceeding 10 μg/L (World Health Organization drinking water limit) to calculate mean probabilities at the district level (n = 599 districts). A spatial integration approach was used to merge these estimates with the third India District-Level Health Survey (DLHS-3) conducted in 2007-08 (n = 643,944 women of reproductive age). Maps of district level arsenic levels and rates of each of the three outcomes were created to visualize the patterns across India. To adjust for significant spatial autocorrelation, spatial error models were fit.

FINDINGS

District-level analysis showed that the average level of stillbirth was 4.3%, recurrent pregnancy loss was 3.3%, and infertility was 8.1%. The average district-level probability of groundwater arsenic levels exceeding 10 μg/L was 42%. After adjustment for sociodemographic factors, and accounting for spatial dependence, at the district level, for each percentage point increase in predicted arsenic levels exceeding 10 μg/L increased, the rates of stillbirths was 4.5% higher (95% confidence interval (CI) 2.4-6.6, p < 0.0001), the rates of RPL are 4.2% higher (95% CI 2.5-5.9, p < 0.0001), and the rates of infertility are 4.4% higher (95% CI 1.2-7.7, p=<0.0001).).

CONCLUSIONS

While arsenic exposure has been implicated with a range of adverse health outcomes, this is one of the first population-level studies to document an association between arsenic and three adverse reproductive pregnancy outcomes. The high levels of spatial correlation suggest that further and targeted efforts to mitigate arsenic in groundwater are needed.