Kidney disease hotspots and water balance in a warming world.

Purpose of review: Geographically localized areas with a high prevalence of kidney disease exist currently in several regions of the world. Although the exact cause is unclear, environmental exposures accelerated by climate change, particularly heat exposure and ground water contamination, are hypothesized as putative risk factors. Aiming to inform investigations of water-related exposures as risk factors for kidney disease, we excavate the history of major water sources in three regions that are described as hotspots of kidney disease: the low-lying coastal regions in El Salvador and Nicaragua, the dry central region in Sri Lanka, and the Central Valley of California.

Recent findings: Historic data indicate that these regions have experienced water scarcity to which several human-engineered solutions were applied; these solutions could be hypothesized to increase residents' exposure to putative kidney toxins including arsenic, fluoride, pesticides, and cyanobacteria. Combined with heat stress experienced in context of climate change, there is potential for multistressor effects on kidney function. Climate change will also amplify water scarcity, and even if regional water sources are not a direct risk factor for development of kidney disease, their scarcity will complicate the treatment of the relatively larger numbers of persons with kidney disease living in these hotspots.

Summary: Nephrologists and kidney disease researchers need to engage in systematic considerations of environmental exposures as potential risk factors for kidney disease, including water sources, their increasing scarcity, and threats to their quality due to changing climate.