Extreme Heat Due to Climate Crisis Increases Risk of Kidney Disease, Study Shows

At a dialysis center in Atlanta, Lauren Kasper, a nurse practitioner, was struck by how many young people in their 20s and 30s were suffering from kidney disease, typically associated with older patients. Her observations led her to co-author a study on the work histories of these patients, many of whom had worked in jobs like landscaping, roofing, and agriculture, exposing them to harsh chemicals and extreme heat.

The study suggests that rising global temperatures are putting workers in heat-stressed environments at heightened risk of developing kidney disease. Kasper points out that it's not just the heat but also humidity that poses a severe threat, as this combination can be particularly dehydrating and damaging to the body.

The summer of 2023 saw record-breaking heat across much of the U.S., and while heat exposure is commonly associated with acute emergencies, researchers are uncovering that prolonged exposure can lead to chronic issues like heart disease, cognitive impairment, and kidney failure. When the body is exposed to high temperatures, the cardiovascular system works overtime to regulate body temperature, and over time, this added strain can cause long-term damage to organs such as the heart and kidneys, particularly for those who labor outdoors.

Kristie Ebi, a professor at the University of Washington’s Center for Health and the Global Environment, noted that outdoor workers, especially those in agricultural settings, are at a high risk of developing chronic kidney disease, a condition that is increasingly being reported in young people in various parts of the world, including Sri Lanka, Central America, India, and the U.S. These patients often lack the usual risk factors like diabetes or high blood pressure, making the connection between heat exposure and kidney disease more concerning.

The causes of this kidney disease are not fully understood, but dehydration from extreme heat exposure is believed to be one of the main factors. Roxana Chicas, a registered nurse and professor at Emory University, describes the situation as a “perfect storm,” where multiple factors, including heat, dehydration, pesticide exposure, and contaminated drinking water, come together to cause severe kidney damage in farm workers.

Kidneys play a vital role in filtering blood, removing waste, and balancing fluid levels in the body. However, extreme heat and dehydration reduce blood flow to the kidneys, depriving them of oxygen and causing inflammation. Over time, this repeated stress can lead to kidney failure. According to Shuchi Anand, a nephrologist at Stanford University, heat acts as an "accelerator" for kidney injuries, pushing workers to the brink of chronic kidney disease.

Farm workers, particularly those who are immigrants and often face limited labor protections, are among the most vulnerable. Many are paid based on how much they pick, rather than by the hour, which incentivizes them to skip water breaks to meet quotas. Chicas’ recent study found that workers who are paid a piece rate had higher rates of acute kidney injury compared to those paid by the hour. These workers often describe their working conditions as akin to being inside an oven, battling extreme heat and humidity while pushing their bodies to the limit to earn a living.

One of the greatest challenges these workers face is accessing healthcare. Many return to their home countries once kidney disease takes hold, as they lack access to medical treatment in the U.S. and rely on family support back home.

In the U.S., heat protections for workers are inconsistent. While some states have implemented standards to protect workers from extreme heat, others, like Florida and Texas, have actively blocked local governments from enacting such protections. The Biden administration proposed a national heat standard in July 2023, which could affect millions of workers, aiming to prevent heat-related illnesses and deaths as climate change continues to worsen heatwaves.

Researchers are still working to understand the long-term effects of living in a hotter world. Although humans have historically adapted to various climates, the rapid rise in temperatures due to the climate crisis is unprecedented. Chicas warns that farmworkers, who are on the frontlines of climate change, are already showing signs of the dangers extreme heat poses. Their experiences could serve as a warning for the general population, as rising global temperatures put everyone at risk for heat-related kidney dysfunction and other health issues.

In conclusion, extreme heat, driven by the climate crisis, is emerging as a major health threat. For outdoor workers, especially in agriculture, the combination of intense heat, dehydration, and long hours of physical labor is contributing to an increase in kidney disease. As global temperatures continue to rise, the risk of heat-related illnesses is likely to extend beyond farmworkers, threatening the health of vulnerable populations across the globe.