Environmental lithium exposure in the North of Chile--I. Natural water sources.

Lithium as an essential element for human life is still a subject of controversy. However, it is accepted that it does have profound neurological effects and is a valuable treatment for bipolar disease. Generally, it occurs in barely trace amounts in groundwater with few major exceptions. One of these is the Northern area of Chile where all potable water and many of the food stuffs contain high levels of lithium; between 100 and 10,000 times higher than most rivers in North America. Inevitably, the local population has been exposed to these levels in their drinking water for as long as the region has been populated. The present report details lithium levels in all the surface water sources of Northern Chile with comparison to that elsewhere. The implications for the local population are discussed and their situation compared to those exposed to other sources of lithium pollution.