For the roughly 2.4 million agricultural workers who labor outdoors across America, the intersection of occupational heat exposure and underlying cardiovascular disease risk is not an abstract concern — it is a daily physiological stress with potentially fatal consequences. Understanding just how widespread that dual burden has become, across two decades and the full geographic sweep of U.S. farming regions, matters enormously for occupational medicine and public health policy alike.
Drawing on 44,388 farmworker records from the National Agricultural Workers Survey spanning 1999 to 2020, this large-scale analysis quantified both temperature exposures — using four absolute heat thresholds ranging from 32.2°C to 40.6°C — and the prevalence of cardiovascular disease and its key precursors: diabetes, hypertension, and elevated cholesterol. The cohort was predominantly Hispanic (81%) and male (73%), with a substantial share living below the poverty line. Joinpoint regression identified temporal trends in heat intensity across six U.S. agricultural regions alongside shifts in CVD-related outcomes, while multivariate logistic modeling probed which farmworker characteristics most strongly predicted cardiovascular risk.
This study stands out for its scale and duration — most prior heat-vulnerability research in this population relied on small, short-term samples that couldn't capture secular trends. The 21-year window is particularly valuable because it overlaps with documented regional warming trends, allowing researchers to connect worsening thermal conditions to evolving health profiles in a workforce with notoriously limited healthcare access. Physiologically, the compounding effect is well-established: hypertension and diabetes impair thermoregulatory capacity, raising core temperature faster under exertion and heat stress. From a practical standpoint, the findings arrive as the United States still lacks a federal occupational heat standard — a regulatory gap this dataset implicitly underscores. The limitation is inherent to the design: repeated cross-sectional surveys cannot establish individual-level causality between heat exposure and cardiovascular outcomes. Still, for epidemiologists and occupational health advocates, this is among the most comprehensive baseline portraits of heat-CVD co-burden in American farmworkers to date — and a clear call for targeted intervention.