Due to long hours outdoors, interacting with heavy machinery, and exposure to toxic chemicals, farmers and other agricultural workers are already vulnerable to a variety of occupational hazards that can threaten their physical health and well-being. These hazards range from heat-related illness, physical injury, and noise-induced hearing loss to respiratory diseases.

Now, research is unveiling a new threat to the farming sector: climate change. According to the article “An Overview of Occupational Risks from Climate Change,” published by faculty members from the Milken Institute School of Public Health at the George Washington University, rising temperatures will have a detrimental impact on the health of agricultural laborers, especially in the areas of heat stress and vector-borne diseases.

MPH@GW recently created the following graphic to illustrate the findings of this article:

Temperatures on the Rise

Agricultural workers are especially susceptible to heat-related conditions. Spending days in the searing heat and high humidity for hours, combined with intense physical exertion, can lead to painful cramps as well as to heat stroke and heat exhaustion.

Consider these facts about heat exposure on agriculture workers in the United States:

• From 1992 to 2006, 423 worker deaths were attributed to heat exposure in the United States. Roughly a quarter of those originated from the agriculture, forestry, fishing, and hunting industries.

• Between 1992 and 2006, the average annual heat-related death rate among crop workers In the United States was 19.5 times the average civilian worker rate, and the rate for crop workers appears to be increasing.

• In Maricopa County, Arizona, during the period 2002–2009, 35 percent of heat-related deaths in men occurred among outdoor workers in agriculture and construction.

Workers in low- and middle-income countries are especially vulnerable to increased heat exposure. Although data about the risks for workers on a global scale are difficult to collect, studies from numerous countries, including Costa Rica, Ghana, Nicaragua, Taiwan, and Thailand, show that heat exposure is already affecting the health of outdoor workers and farmers. Any increase in global temperatures also could result in an increase in the numbers of workers who are exposed to dangerous levels of heat.

Prolonged exposure to heat not only poses health risks; it also hampers productivity. One study on blueberry pickers in California found that temperatures above 38 degrees Celsius (100 degrees Fahrenheit) lowered productivity by 1.1 kilograms (2.33 pounds) per hour, which represented a 12 percent decrease. Loss of productivity can translate into less income for workers whose salaries are based on output.

Excessive heat also can make workers less alert, leading to safety issues. A 2014 report showed that heat exposure could potentially have a dramatic impact on the productivity of outdoor workers, “particularly those working in construction, utility maintenance, landscaping, and agriculture.” According to this same report, output for workers in these industries “could be reduced by as much as 3 percent by the end of the century.”

Vector-Borne Diseases

According to the World Health Organization, vector-borne diseases—diseases such as Rift Valley Fever that are transmitted through vectors like mosquitoes—are already responsible for one-sixth of disabilities and illnesses suffered worldwide. The warmer temperatures resulting from climate change translate into longer warm seasons and shorter and milder winters—two factors that set a hospitable stage for these disease-carrying organisms.

Agricultural workers that handle animal tissue during slaughtering, butchering, assisting with births, or other tasks are particularly at risk. For example, a markedly higher incidence of Rift Valley Fever has been found in slaughterhouse workers and cattle farmers. More of these workers are expected to be exposed to vector-borne diseases as climate change brings warmer temperatures for prolonged periods of time across a greater number of regions.

What Can Be Done?

By the year 2050, the world’s population is expected to reach 9.1 billion, a 34 percent increase compared to today. According to the United Nations Food and Agriculture Organization, feeding this larger population will require the world’s food production to increase by 70 percent. Given this reality and the predicted continuing trend of global warming, stronger protections against heat, pathogens, and other hazards for agricultural workers are imperative.

Going forward, some potential strategies for protecting the health of agricultural and other at-risk workers include an increase in:

• Research designed to better define worker populations at risk within different geographic regions.

• Occupation-specific surveillance programs that can track patterns of injury and illness as they relate to the effects of climate change.

• Worker safety practices that include modified workday schedules that reduce hazard exposure, increased frequency of breaks, and better access to personal protective gear.

• Safety monitoring technologies, such as sensors that warn workers about impending excessive levels of heat or other hazards.

Employers and safety officials must make it a priority to educate themselves about the emerging hazards related to global warming. After all, keeping in step with global demands across all sectors means protecting the health of the workers that are the lifeblood of these industries.

Julie Potyraj is the Community Manager of MPH@GW and HealthInformatics@GW. She is a student at the Milken Institute School of Public Health at the George Washington University.