Climate Change and Industrial Hygiene
What does climate change have to do with industrial hygiene? Well, the guiding tenets of our profession are “anticipation, recognition, evaluation, control, and confirmation,” and these certainly apply to emerging issues such as the impact of climate change on worker safety and health. A report released in May 2014 by the U.S. Global Change Research Program concluded that weather and climate patterns are changing, causing increasingly frequent and severe heat waves, wildland fires, drought, flooding, and extreme weather events, as well as a rise in sea levels. What was a theoretical possibility some 20 or so years ago has now become a recognized public health threat. Global climate change ha​s become one of the most visible environmental concerns of the 21st century, and it has the potential to affect worker health and safety both directly and indirectly. The purpose of this article is not to debate the potential causes of climate change, but to discuss what we can do as safety and health professionals in response to a changing climate. It is important that we educate and position ourselves so we can proactively address the associated worker safety and health issues, and identify controls for mitigating hazards and adapting to our changing climate. OCCUPATIONAL HAZARDS OF A CHANGING CLIMATE What do we know about how climate change affects worker safety and health, and how should we respond? What information and tools do we need to protect workers? How do we respond to current and anticipated h​ealth impacts?
In general, we can look at how climate change can affect workers from these perspectives:
  • amplification of known safety and health hazards such as severe weather events, heat, wildland fire, and infectious disease
  • new, unanticipated, or unrecognized hazards (increased infectious disease vector ranges, increase in pesticide use)
  • hazards that result from our response to climate change such as the development of renewable energy, recycling, carbon sequestration, and material substitution
During the last decade, more than 300 civilian workers died on the job due to environmental heat exposure. In addition, heat could be a contributing factor to many other severe or fatal injuries or illnesses.
RESOURCES​ American Journal of Epidemiology: “A focus of lyme disease in Monmoutei County, New Jersey” (September 1984). American Journal of Epidemiology: “Lyme disease in outdoor workers: risk factors, preventive measures, and tick removal methods” (May 1990). American Journal of Public Health: “Lyme disea​se in New Jersey outdoor workers: a statewide survey of seroprevalence and tick exposure” (October 1990). American Journal of Public Health: “Workers: the Climate Canaries” (October 2014). CDC: “Chikungunya virus” (2014). CDC: “Climate change and occupational safety and health” (2014). CDC: “Lyme Disease” (2011). Economic Policy Institute: “Counting Up To Green, Assessing the green economy and its implications for growth and equity” (2012). Industrial Health: “Making green jobs safe” (August 2010). International Journal of Biometeorology: “The epidemiology of occupational heat exposure in the United States: a review of the literature and assessment of research needs in a changing climate” (October 2014). International Journal of Industrial Ergonomics: “Effects of work in a hot environment on repeated performances of multiple types of simple mental tasks,” (January 2010). Institute of Medicine: Climate Change, the Indoor Environment, and Health (2011). Institute of Medicine: The influence of global environmental change on infectious disease dynamics (2014). Intergovernmental Panel on Climate Change: “Climate Change 2013: The Physical Science Basis” (2013). ​ JAMA: “Chikungunya virus transmission found in the United States: US health authorities brace for wider spread” (August 2014). Journal of Occupational and Environmental Hygiene: “Climate change and occupational safety and health: establishing a preliminary framework” (September 2009). Journal of Occupational and Environmental Medicine: “Occupational coccidioidomycosis in California: outbreak investigation, respirator recommendations, and surveillance findings” (May 2012). Morbidity and Mortality Weekly Report: Coccidioidomycosis among cast and crew members at an outdoor television filming event—California” (April 2014). ​ National Council for Occupational Safety and Health: “Sustainable and Safe Recycling” (PDF, 2015). National Interagency Fire Center (NIFC): Fire information and statistics. ​​ NIOSH: “Fighting Wildfires” (2014).
NIOSH: “Hazard evaluation and technical assistance report: Evaluation of Coccidioides Exposures and Coccidioidomycosis Infections among Prison Employees” (2014). Science: “Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity” (August 2006). U.S. Global Change Research Program: “Climate Change Impacts in the United States: The Third National Climate Assessment” (2014).
A number of worker populations may be particularly vulnerable to threats from climate change, including outdoor workers, emergency responders, commercial fishermen, healthcare workers, firefighters, farmers, transportation workers, and workers in hot indoor environments such as warehouses and factories. It is also likely that the variety of occupations and number of workers exposed will increase. The effect of climate change on workers is of particular concern because workers may be exposed to conditions that the general public can elect to avoid (a situation not unique to climate change) and because employment increases are predicted for the most at-risk workers (for example, wildland firefighters). Potential health consequences to workers who may be affected by a changing climate include asthma, respiratory allergies, and airway diseases; cancer; cardiovascular disease and stroke; heat-related morbidity and mortality; mental health and stress-related disorders; neurological diseases and disorders; waterborne diseases; weather-related morbidity and mortality; and vector-borne, zoonotic, and other infectious diseases such as Lyme disease, Valley Fever (coccidioidomycosis), chikungunya, and dengue. Climate change directly affects workers through hazards such as increased ambient temperatures, air pollution, extreme weather, and increased prevalence and geographic range of vector-borne and other infectious diseases. Occupational hazards resulting from the indirect effects of climate change are likely to occur from industrial transitions, emerging “green” industries (renewable energy, recycling, and carbon sequestration, for example), increased use of pesticides, changes to the work force resulting from altered economic activities, and changes in the built environment. Higher temperatures or longer, more frequent periods of heat may result in greater occupational heat stress, potentially leading to more cases of heat-related illnesses (heat stroke, heat exhaustion, and so on), decreased chemical tolerance, and fatigue. Exposure to increased temperature can also result in reduced vigilance and increased risk of injury or lapses in safety. Thousands of heat-related illnesses occur each year in the United States. During the last decade, more than 300 civilian workers died on the job due to environmental heat exposure. In addition, heat could be a contributing factor to many other severe or fatal injuries or illnesses, such as those caused by falls or myocardial infarctions. With a warming climate and more frequent extreme weather events predicted, heat exposure and heat stress are becoming a prominent employee safety issue. Even small changes in average temperature can potentially translate into a substantial increase in the number of deaths and cases of severe illness. Air pollution is affected by climate change, and outdoor workers have longer exposure to air pollutants, which may be linked to chronic health effects such as respiratory diseases and allergic disorders. For example, elevated temperatures can increase levels of air pollution (including ground-level ozone) and wildfire smoke, which contains particulate matter, carbon monoxide, nitrogen oxides, and various volatile organic compounds and can significantly reduce air quality, both locally and in areas downwind of fires. Extreme weather events or natural disasters such as floods, landslides, storms, lightning, droughts, and wildfires are becoming more frequent and intense. As the frequency and intensity of these events increases, there will be a need for more emergency responders. Workers involved in rescue and cleanup will have more exposure to the risky conditions created by weather disasters. For example, climate change is currently increasing the vulnerability of many forests to wildfire. Since 1983, the National Interagency Fire Center (NIFC) has documented an average of 72,000 wildfires per year. The data do not show an obvious trend during this time, but the extent of area burned by wildfires each year appears to have increased since the 1980s. According to NIFC data, of the 10 years with the largest acreage burned, nine have occurred since 2000. This period coincides with many of the warmest years on record. And there is something of a synergistic effect: climate change influences fire, and fire activity can influence climate. The fire season varies depending on location but has historically been from mid-April through October in the U.S. In the last 25 years, the fire season has increased by an average of 78 days. Thus firefighters will have longer durations of exposures and less recovery time between fire seasons. The increase in wildfires will require response from an ever-increasing number of firefighters, including volunteers. Statistics from the Federal Emergency Management Agency indicate that from 2000 to 2013, almost 300 wildland firefighters died while on duty. Common hazards faced by wildland firefighters can include burns, heat-related illnesses, smoke inhalation, and injuries from slips, trips, and falls. In addition, due to prolonged intense physical exertion, wildland firefighters are at risk for rhabdomyolysis, a condition resulting from an increase in core body temperature and subsequent breakdown of muscle cells and the release of their contents into the bloodstream. Extreme weather events may also cause damage to infrastructure (power lines, roads, and transportation) and buildings. Workers could be put in new or unfamiliar circumstances leading to a high risk of traumatic injury. Some workers may be at increased risk of violence if mobility, electricity, communication, food, and shelter become compromised. In summary, extreme weather events and weather disasters are expected to lead to an increased risk for occupational fatalities, injuries, diseases, and mental stress. Changing temperatures and shifting rainfall can affect habitats of vectors, pathogens, hosts, and allergens. Increased prevalence and distribution of water-borne and food-borne pathogens could affect outdoor, emergency response, and healthcare workers. Pollen may increase from earlier flowering and longer pollen seasons. Increasing numbers of hurricanes and floods could lead to more houses with mold and more remediation and construction workers exposed. Increasing temperatures and atmospheric carbon dioxide may increase the growth and spread of poison ivy and other poisonous plants.
Figure 1. Longer, more frequent periods of heat may result in greater occupational heat stress.
Figure 2. Global temperature change: decade averages (source: National Oceanic and Atmospheric Administration).
Temperature changes affect insect vectors, increasing their populations, extending their transmission seasons, and expanding their distribution seasonally and spatially. Outdoor workers may be at increased risk for mosquito-borne diseases (such as West Nile) and tick-borne diseases (such as Lyme disease). Previous research has found that outdoor workers were five times more likely to acquire Lyme disease than indoor workers. Vector ranges will continue to expand, and new diseases not previously prevalent in the U.S. (dengue and chikungunya Virus are examples) will be introduced. Valley Fever has increasingly been found to be an occupational hazard—archeologists are among the exposed worker populations—and its endemic range could increase with a changing climate. THE IH RESPONSE As our society responds to climate change, “green” industries such as renewable energy production and recycling are projected to grow, and some traditional industries are expected to transition toward activities such as retrofitting buildings for energy conservation. These changes present opportunities for industrial hygieni​sts to apply their knowledge of well-understood hazards such as slips, trips, and falls; musculoskeletal disorders; and chemical exposures in new environments. Vigilance is required to identify unanticipated hazards resulting from new work practices, or use of alternative chemicals and materials. What can we do as industrial hygienists? Staying informed about emerging issues and hazards associated with climate change will help us to respond and implement effective prevention strategies. There is much we can do using established tools and strategies for hazards that we routinely deal with (temperature extremes, pesticide use, and so on) that may be exacerbated as our climate changes. As we identify emerging issues we can alert researchers, regulators, and PPE manufacturers of specific worker safety and health needs. We can also educate others, including company executives and safety professionals, about how to prepare and respond. Industrial hygienists have the skills and knowledge needed to develop specific company-level plans to address this emerging threat to worker safety and health. Please check the NIOSH climate change topic page for additional information and to stay informed of climate change and work-related issues. MAX KIEFER, MS, CIH, is the interim associate director for science in the NIOSH Western States Division. He can be reached at JOANNA WATSON, MSC, DPHIL, is an epidemiologist in the NIOSH Western States Division and project officer for the NIOSH Climate Change Initiative. She can be reached at