Roshan Thapa, MD; Pinky Jha, MD
WMJ. 2026;125(3):333,335. Published August 11, 2026.
To the Editor:
Climate change is increasingly shaping patterns of human disease, and chronic kidney disease of unknown etiology (CKDu) has emerged as a sentinel example of a climate-sensitive illness.1 First recognized among agricultural workers in El Salvador in the 1990s as Mesoamerican nephropathy, CKDu now affects individuals across India, the Middle East, Africa, and the Americas. Unlike conventional kidney disease linked to diabetes or hypertension, CKDu predominantly affects younger workers exposed to extreme heat, dehydration, and intense physical labor. Recurrent heat stress leads to repeated subclinical kidney injury that progresses to chronic kidney failure.2
A similar crisis is affecting migrant workers from Nepal who return from the Middle East. Every year, over 1.5 million people leave Nepal to work in the extreme heat of the Gulf region, where temperatures often hit 45 °C to 50 °C (113 °F to 122 °F). While the money they send home makes up nearly a quarter of Nepal’s entire economy, occupational protections remain limited. Data suggest that over 90% of returnee migrant workers presenting with renal failure have “unknown etiology,” with many requiring dialysis before age 40.3 Similar CKDu clusters have been documented among sugarcane workers in Central America, miners, and agricultural laborers across South Asia and Africa, underscoring that this is a global climate-linked occupational disease.3-5
Pathophysiology is increasingly understood for every 1°C rise in WetBulb Globe Temperature (WBGT); the risk of acute kidney injury increases by approximately 18%. Recurrent heat stress, dehydration, and nonsteroidal anti-inflammatory drug (NSAID) use contribute to subclinical tubular injury and medullary hypoxia, ultimately leading to irreversible renal failure.4 Current safeguards are inadequate, as occupational protections are often clock-based rather than WBGT-based, and migration systems lack mandatory baseline renal screening.
We propose 3 priorities: (1) awareness – recognizing CKDu as a climate-sensitive occupational disease and strengthening surveillance; (2) advocacy – integrating kidney health into climate and labor policy; and (3) accountability: enforcing WBGT-based stop-work laws and evidence-based water–rest–shade protocols. Although these patterns have been described primarily abroad, rising temperatures and frequent heat waves in the United States – including the Midwest – underscore the need for greater clinical awareness of heat-related illness and occupational health risks, especially for our agricultural and construction sectors. Health care providers and educators can contribute by raising awareness, integrating climate considerations into clinical practice and curricula, promoting research, and advocating for policies that protect vulnerable populations. Protecting manual laborers from heat-related kidney disease is both a clinical priority and an issue of climate justice. As climate change alters occupational disease patterns worldwide, the medical community must support evidence-based policies to protect vulnerable migrant workers.
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- Bell ML, Gasparrini A, Benjamin GC. Climate change, extreme heat, and health. N Engl J Med. 2024;390(19):1793–1801. doi:10.1056/NEJMra2210769
- Sorensen C, Garcia-Trabanino R. A new era of climate medicine: addressing heat-triggered renal disease. N Engl J Med. 2019;381:693–696. doi:10.1056/NEJMp1907859
- Aryal N, Regmi PR, Sedhain A, et al. Chronic kidney risk among Nepalese migrant workers in the countries of Gulf and Malaysia: a population-based cross-sectional survey in Nepal. MedRxiv. Preprint posted online May 22, 2025. doi:10.1101/2025.05.15.25327703
- Elinder CG. Heat-induced kidney disease: understanding the impact. J Intern Med. 2025;297(1):101–112. doi:10.1111/joim.20037
- García-Trabanino R, Jarquín E, Wesseling C, et al. Heat stress, dehydration, and kidney function in sugarcane cutters in El Salvador– A cross-shift study of workers at risk of Mesoamerican nephropathy. Environ Res. 2015;142l765-746. doi:10.1016/j.envres.2015.07.007