Climate change poses a two-pronged threat to workers. Rising temperatures can induce injuries and illnesses for outdoor workers and those responding to natural disasters. Increasingly hotter temperatures indoors and out can also amplify existing injuries and illnesses for workers with chronic conditions such as cardiovascular disease and kidney disease.
The World Health Organization has declared climate change as the greatest public health threat of the 21st century. On October 11, 2022, a group of researchers and practitioners hosted a workshop, “Climate Impacts and Solutions for Outdoor Workers” at the 3rd International Symposium for Total Worker Health® in Bethesda, MD.
Mike Van Dyke, PhD, CIH, associate professor and director of interdisciplinary education at the Center for Health, Work & Environment at the Colorado School of Public Health presented a comprehension review of heat stress and its impact on outdoor work. Rises in global average temperatures affect some locations in the world more than others. Increased average temperatures mean more hot days and therefore more days when heat stress may be an issue.
"There is crossover here with sports science,
the things we do to protect our athletes,
we should also be considering to protect our workers.”
- Mike Van Dyke, PhD, CIH
Individualized risk of heat stress
The U.S. Bureau of Labor Statistics reports 344 fatalities among U.S. workers due to heat stress from 2011-2019. Heat stress is caused by a rise in core body temperature, which is different than skin temperature, and very individualized. Core body temperature can be difficult to measure but is affected by outdoor temperatures and the effects of heat transfer through conduction, convection and radiation. Heat stress disorders include heat exhaustion and heat stroke. Like frostbite, people who have previously experienced heat stress are at an increased risk of experiencing it again.
Van Dyke suggested several strategies to address heat stress at work including (1) work practice controls such as acclimatization and required rest during periods of high temperatures; (2) close observation of especially vigorous work during high temperatures; and (3) frequent hydration breaks for outdoor workers.
“Acclimatization for workers is the best thing we can do to prevent and manage heat stress,” Van Dyke said. This may mean starting workers with two hours of lower intensity work per shift during high temperatures and building up individual capacity. “On average, it takes 7-14 days to properly acclimatize workers,” Van Dyke said. “It’s time to consider our outdoor workers as ‘athletes.’ There is crossover here with sports science, the things we do to protect our athletes, we should also be considering to protect our workers.”
Workers and water
Roxana Chicas, PhD, RN, assistant professor at the School of Nursing at Emory University, discussed the impact of heat stress on specific injuries. Agricultural workers such as farmers are 35 times more likely to die of a heat related injury or illness than the general working public. Construction workers are 14 times more likely. Chicas focuses her research and occupational and environmental health practices on these high-risk industries.
“We only water our grass at certain times of the day because it is healthier for our lawns,” Chicas said. “Why don’t we treat our outdoor workers the same?” Healthier practices for workers include moving physically demanding activities to cooler times of the day; providing rest breaks in cooled, shaded areas; and making cool or cold drinking water accessible at the job site. Chicas also expressed a need for worker training on how to identify the signs of heat stress so that people know what to do when someone is getting sick.
The Washington State Department of Labor & Industries has comprehensive standards in place and free training resources to protect workers in extreme heat. The relationship between our climate and how we work may look different, but the importance of understanding that relationship and developing strategies to mitigate potential harmful health effects holds true, no matter where we are located.
April 23, 2024