Mineral nutrients and toxicants in Bangladesh groundwater—do we need a holistic approach to water quality?

Groundwater, a drinking water source for > 95% of inhabitants living in Bangladesh, has received much attention because of its naturally occurring Arsenic (As), but the coupling or decoupling of As toxicity by other water constituents remains unexplored. Although food provides nutrients, in rural settings, where people subsist on a low nutrient diet, drinking-water-nutrients may supply quantities significant for human health thereby preventing diseases. Here, we show, using augmented datasets from Bangladesh, that the content of groundwater is such that in some areas individuals obtain up to 50% or more of the Recommended Daily Intake (RDI) of some nutrients (e.g., calcium, magnesium, iron) from just two litres of drinking water. We also show the spatial association of groundwater nutrients and health outcomes in Bangladesh. We suggest, therefore, that a holistic approach, i.r., considering the entire range of groundwater constituents, should be considered when undertaking health impact studies of groundwater.