Heat exposure of U.S. agricultural workers in a warming climate
Abstract
Heat has historically resulted in more mortality than any other severe
weather-related phenomenon in the United States, with the U.S. Centers
for Disease Control attributing more than six hundred deaths to extreme
heat each year. Agricultural workers are particularly vulnerable to
environmental heat exposure: mortality rates due to heat amongst crop
workers are twenty times higher than in the general worker population.
The vulnerability of this group of workers to heat is exacerbated by
factors such as economic vulnerability, immigration status, language
barriers, access to health care, and the absence of worker heat
standards in all but three of the fifty United States. Climate change
threatens to increase the risk of heat-related illness in agricultural
workers, but so far there has been no nation-wide evaluation of the
expected change in heat exposure in a warmer climate for this group of
workers. Here, we estimate baseline and future exposure of agricultural
workers in the main growing regions of the continental U.S. to extreme
heat. Given the diverse health impacts of different types of heat
events, we compare metrics for both single day extremes and multi-day
heat waves, and calculate how these statistics will change at the county
level with 2 and 4 degrees Celsius of global warming. Our findings serve
as a guideline for determining regionally appropriate heat standards,
and underscore the need for agencies in all agricultural states to make
preparations for a warmer climate.