In the 1990s, health officials noticed that chronic kidney disease was on the rise in Central America. An epidemic seemed to be raging among farmworkers who toiled in sugarcane fields on the Pacific Coast in El Salvador and Costa Rica one of the hottest areas in the region. To date, more than 20,000 people have died in the epidemic, and thousands of others have had to go on kidney dialysis to survive.
Researchers are now coming together around a hypothesis about whats driving a little-appreciated epidemic, known as Mesoamerican nephropathy.
One main suspect: global warming. It has become a leading hypothesis to explain not just Mesoamerican nephropathy but a similar uptick in chronic kidney disease in India and Southeast Asia. The victims could be called climate canaries.
Roberto Lucchini, an environmental and public health professor at Mount Sinai whos been studying the phenomenon, calls this the first epidemic thats directly attributable to climate change. It was not recognized before the rise in temperatures, he said, and the epidemic of these cases is currently observed in the countries that are more affected by [global warming] in the last decades, from Central America to India and Southeast Asia.
The epidemic might also be happening closer to home. Recent studies focused on California and Florida suggest the disease may already be afflicting people who work outdoors in the southern US too.
The basic idea: When people are exposed to long stretches of extreme heat, they sweat more. If they dont rehydrate, or dont have access to clean drinking water, the kidneys, which are supposed to filter waste and regulate fluid in the body, get stressed. Over time, that stress can lead to kidney stones and chronic damage.
The hypothesis is that weeks and months of sustained, acute kidney injury [due to heat exposure] could potentially destroy the kidneys ability to function, said Linda McCauley, dean of the nursing school at Emory University, who has been studying kidney failure among farmworkers in Florida.