Public health journal Environmental Research last week published study results from a groundbreaking epidemiological investigation into the causes of Chronic Kidney Disease of nontraditional causes (CKDu) in Central America.

This disease, also known as Mesoamerican Nephropathy (MeN), has killed over 20,000 people, most of them sugarcane workers.

The study, which took place at Salvadoran sugar mill El Angel, examined 189 sugarcane cutters before and after work shifts, or “cross shift,” measuring biomarkers indicative of hydration and kidney function. “It is the first time that an investigation of this kind (cross shift) has been realized among cane cutters susceptible to developing [CKDu],” said Dr. Ramón Garcia-Trabanino, a nephrologist and principal investigator of the study.

Results showed physiological damage to the kidneys over the course of the workday due to heat stress and dehydration. These findings support the leading hypothesis of the causes of CKDu, which identifies workload with repeated heat stress and dehydration as the principal driver of disease. “[The study] succeeded in demonstrating an association between heat stress and kidney damage,” García-Trabanino said. “We observed once again that the disease is more frequent in coastal regions and that it is associated directly with levels of heat stress.”

These results provide a scientific basis for intervening in working conditions to provide workers with better access to water, rest, and shade, according to researchers. “With the exception of climate change, all other risk factors observed in this study (dehydration, [excess uric acid], etc.) are modifiable factors through relatively simple interventions and therefore we must intervene as soon as possible to stop the damage,” García-Trabanino said.

During its last harvest, the El Angel mill opened its doors to host the Worker Health and Efficiency (WE) Program, the first-ever concerted workplace intervention targeting CKDu prevention. The WE Program is an ongoing collaboration between research institutions Karolinska Institutet, Lund University, Gothenburg University, London School of Health and Tropical Medicine, Imperial College London, University of Birmingham, SALTRA, and the US Occupational Health and Safety Agency with consultation from the Centers for Disease Control and Prevention (CDC)-NIOSH and the US Army Research Institute of Environmental Medicine.

Both the study published last week and the WE Program intervention were facilitated by La Isla Foundation (LIF) and Solidaridad Network with funding from the Dutch National Postcode Lottery.

Read and download the open source study in full here.