Climate change and Chronic Kidney Disease in Outdoor Workers in Latin America: a silent epidemic that demands action

Climate change is leading to a rise in global temperatures and an impact on outdoor workers’ kidney health, but employers and healthcare professionals can help prevent the negative effects of extreme heat exposure, argues Dr Magdalena Madero, Chief of Nephrology at Instituto Nacional de Cardiol in Mexico

Chronic Kidney Disease of Non-Traditional Origin (CKDnt) has emerged as a critical public health issue, especially among outdoor workers in Latin America. This disease, which is strongly associated with heat stress and other occupational hazards, disproportionately affects agricultural labourers, construction workers, and others. There is an urgent need for more effective preventive strategies as the impacts of climate change can exacerbate CKDnt.

Understanding CKDnt: A Modern Health Crisis

CKDnt was first identified in Central American agricultural communities, particularly among sugarcane workers, in the 1990s.¹ Unlike traditional CKD, often linked to diabetes or hypertension, CKDnt affects otherwise healthy young adults, predominantly in impoverished settings. Repeated episodes of dehydration and acute kidney injury play a pivotal role in its early onset which can lead to irreversible kidney fibrosis.

Studies from Central America, India, and Sri Lanka are shedding light on the connection between occupational heat stress and CKDnt.^2,3 Agricultural workers exposed to prolonged high temperatures often lack access to proper hydration, rest, or shade - essential protections against the onset of CKDnt, as well as other kidney diseases. As heat waves become more frequent and prolonged due to climate change,⁴ CKDnt will continue to rise if preventive measures are not adopted. 

In Latin America, sugarcane workers are among the most vulnerable, particularly in hotspots like El Salvador, Guatemala, and Mexico’s Veracruz region.⁵ However, CKDnt is not limited to sugarcane farming. This disease also affects construction workers, fishermen, and women in similar conditions. It’s a socioeconomic issue, tightly intertwined with poverty and inadequate worker protections.

Alarmingly, climate change is expected to worsen CKDnt’s impact. Increasingly frequent heatwaves amplify the occupational hazards faced by these workers, potentially expanding the disease’s reach across Latin America and beyond.

The Economic and Healthcare Burden

Policymakers and governments in Latin America need to understand that the ramifications of CKDnt extend beyond individual suffering to encompass broader socioeconomic and healthcare challenges.

The majority of agricultural workers in Central America earn a minimum wage and often do not have health insurance to access care in healthcare facilities. Many patients cannot afford expensive renal replacement therapies such as dialysis, which means in regions without robust publicly-funded healthcare systems, these patients often face premature death.

Out-of-pocket costs for treatments are devastating for low-income families, while healthcare systems struggle to manage the influx of patients requiring these expensive interventions. In some cases, patients which require dialysis three times a week are forced to only one, as costs are prohibitive. Moreover, labour productivity suffers as affected workers—often the economic backbone of rural communities—are sidelined by illness or stigma.

Strategies for Prevention and Intervention

Considering the costs, prevention, rather than treatment, must be the cornerstone of addressing CKDnt. Strategies such as the “Adelante Initiative” in Nicaragua have shown success by incorporating water, shade, and rest programmes into labour routines, significantly reducing kidney injury markers.⁶ It is crucial that employers monitor workers’ hydration status, kidney function, and weight changes to identify at-risk individuals early. Employers should also introduce hydration programmes, the mechanization of field labour, and periodic health screenings.

At a national policy level, governments must introduce and enforce labour protections, provide health insurance to outdoor workers, and train primary care physicians to diagnose and manage CKDnt effectively. There are not enough nephrology specialists in Central America – so there is a need for primary care physicians to be trained in kidney disease diagnosis and treatment. National and regional health authorities can play a critical role by adopting standardized screening protocols and bolstering preventive measures in high-risk populations.

Building momentum in research and awareness

Despite progress, CKDnt remains under-researched and poorly understood. Collaborative initiatives like the National Institutes of Health (NIH) funded “CKDnt Cure” project, which aims to uncover the disease’s underlying mechanisms and risk factors are commended,⁷ but it is important that researchers also address the research gaps in chemical exposure on kidney health and conduct kidney biopsies to better understand CKDnt pathology.

Awareness campaigns targeting employers and the public are equally crucial. Although most industries have started implementing preventive measures, more systemic changes are needed. Local researchers must be involved to ensure trust and culturally relevant solutions as this is not just a medical issue but a societal one.

Early screening and prevention are key. We now have effective therapies for CKD, making early intervention both feasible and cost-effective. Furthermore, the environmental burden of dialysis on water usage and the shift to green nephrology are also other driving factors to push for the prevention agenda.

Conclusion

CKDnt is a silent epidemic that demands urgent action as we grapple with climate change. By addressing its root causes—poverty, heat and occupational hazards, and inadequate healthcare—governments, employers, and the medical community can mitigate its devastating impact. There is a need for comprehensive strategies that prioritize prevention, equity, and sustainability to safeguard the health of outdoor workers in Latin America and beyond.

Magdalena Madero, MD, is a Professor of Medicine and the Chief of Nephrology at the National Heart Institute in Mexico City. She was trained in Internal Medicine at St Elisabeth’s Medical Center in Boston, MA, and then underwent her nephrology training at Tufts Medical Center also in Boston, MA. She went back to Mexico City in 2007 where she joined the nephrology staff at the National Heart Institute and became the Head of the Nephrology Division in 2011. Dr. Madero`s research interests include CKD progression, complications and outcomes, CKD of unknown origin and hemodialysis.  She has over 130 publications and more than 9000 citations. She was awarded with the Miguel Aleman award in 2015, given to the most outstanding young researcher in the country. As part of her educational activities, she runs the largest renal fellowship programs in the country at the National Heart Institute (affiliated to the main National Mexican University [UNAM]) in addition to teaching the nephrology course at the undergraduate Panamerican University medical school. She enjoys patient care and is active in taking care of CKD patients. She was the former President of the Mexican Society of Nephrology (IMIN-2014) , served as International Editor for the American Journal of Kidney Diseases (2016-2021) and as a member of the Kidney Disease Improving Global Outcomes Executive Committee (2018-2021) and chaired the KDIGO executive nominating committee (2022-2023). She served as the Chair for the International Society of Nephrology (ISN)  for Latin America and the Caribbean (2019-2023) and is on council for the International Society of Peritoneal Dialysis (2022-2024). She was part of the KDIGO CKD 2024  guideline writing group and has been part of the steering committee at some KDIGO controversies meetings. She led the Mexican kidney disease project (2022-2024) to grant universal dialysis coverage for the uninsured patients in Mexico City.  She co-chaired the scientific committee for WCN 2024 and ISPD meeting 2024. More recently she became an Associate Editor for the Journal of the American Society of Nephrology (2024-2029).