High Uranium Concentrations in the Groundwater of the Rio de Janeiro State, Brazil, Mountainous Region

Unexpectedly high uranium concentrations, up to 930 µg L-1, approximately thirty times higher than the World Health Organization (WHO) guidance level, were observed in groundwater samples from the mountainous region near Rio de Janeiro City, the so-called “Região Serrana”, approximately 60 km from the city. This region is characterized by a large number of tourist activities and water-related industries, such as mineral water and breweries that can be impacted by these findings. In addition, the water supplies in small communities of this region are partially or entirely based on groundw...