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How Climate Change Intensifies the Social and Environmental Determinants of Worker Health

A home damaged by a climate disaster


A.3.2 The frequency and intensity of heavy precipitation events have increased since the 1950s over most land area for which observational data are sufficient for trend analysis (high confidence), and human-induced climate change is likely the main driver. -2021 IPCC Report1


Ernesto Moreno Aguirre worked two jobs, as a construction worker and dishwasher, to make ends meet, in the borough of Queens in New York City.  His family of four was living in an illegal basement unit, one of the few apartments that he could manage to rent without paperwork. When the remnants of Hurricane Ida hit New York City, Moreno Aguirre’s home – and all his family’s possessions, all he had brought from his home country of Colombia, and all they had in the US -- was under several feet of water in minutes.2

The record-breaking deluge from Hurricane Ida found the weak points in an aging stormwater infrastructure that resulted in deaths in flooded basement apartments. Such high volumes of rain are becoming more common as the climate crisis intensifies. There have been more intense hurricanes in recent years. Hurricanes gather more water from climate-change-warmed oceans and seas, then move more slowly than in the past as they release torrents of this warmer water.345 The combination of slower storm movement and greater water capacity in these storms results in more damage.

Most of the basement apartments that were affected were unpermitted. Families like Moreno Aguirre’s -- immigrants, people lacking documentation or financial stability to rent better apartments, newly arrived migrants with few resources to find better accommodation – were swept underwater.  In New York City, 11 of the 13 deaths from Hurricane Ida-related flooding were in basement apartments.

After the storm, the Federal Emergency Management Agency (FEMA) began providing $10 million of aid to qualifying residents whose homes were damaged or destroyed. Immigrants who lack authorization to live in the US, however, are ineligible for this aid.

Families like Moreno Aguirre’s bear double setbacks to this climate-induced disaster: damaged or unlivable housing, plus few resources to move forward. Some may be displaced and lose their jobs, jeopardizing their food security, which leads to food-related health issues like malnutrition, diabetes, and obesity.67 Others may move back into water-damaged homes and may suffer short- and long-term health consequences of exposure to molds.

These are just a few of the heightened and compounding social determinants of health (SDOH) that vulnerable workers across the country face during and after a disaster. SDOHs are the conditions in a person’s environments – the home, the neighborhood, the workplace – that may influence that person’s health and quality of life. For many low-income workers around the country, a climate disaster amplifies the negative impacts of SDOHs related to their work and home.

Disaster-influenced SDOHs are not restricted to metropolitan areas. In rural eastern North Carolina, agricultural workers in farm housing were displaced for months and many lost their jobs when unprecedented flood waters destroyed crops, concentrated animal feeding operations, and farm housing during Hurricane Florence in 2018.8 The floodwater itself was tainted with swine and human waste, which remained in the mud that coated the walls of agricultural worker housing after floodwaters receded. A month after the hurricane, local waterways still had dangerous levels of E. Coli and other bacteria.9 Like in New York City, those without authorization to live and work in the US had fewer resources to recover from the disaster and few employment opportunities that could provide better housing. Many lost their jobs as damaged crops were unsuitable for harvest. As climate change progresses, such displacement of low-income marginalized workers is anticipated to occur with increased frequency.


§5141.1 Protection from Wildfire Smoke. (1) This section applies to workplaces where: (A) The current Air Quality Index (current AQI) for PM2.5 is 151 or greater, regardless of the AQI for other pollutants; and (B) The employer should reasonably anticipate that employees may be exposed to wildfire smoke. -California OSHA Smoke Standard10

In California, years in which megafires burned through a combined million acres of forest used to be extremely rare.11 In the last five years, however, they have occurred every year. In 2020, CAL FIRE recorded over 3,600,00 acres burned and as of mid-September 2021 the agency had already tallied over 2,300,000 acres burned.12 This increase in acreage burned follows the predictions of climate scientists that a drier and hotter climate would increase the frequency and intensity of wildfires. Climate change’s impact is intensified by historical forest management; fire suppression was the dominant strategy, and prescribed burns to reduce undergrowth in mature forests had been largely underutilized as a strategy to slow megafires until recent years.13

The agricultural sector is one of the largest industries in California, and hundreds of thousands of agricultural workers fuel this industry.14 Many of these workers lack authorization to live and work in the US. Others arrive in the US temporarily on H2-A work visas. Both sets of workers lack agency in their workplaces to report unsafe working conditions or mistreatment, despite the work being one of the most hazardous and lowest paying positions in the country.15

Disasters intensify these work-related SDOHs. Megafires blow smoke across the state, and workers hundreds of miles away from a fire may be impacted by its smoke. The fine particles in wildfire smoke are especially harmful to agricultural workers, whose SDOHs increase their risk for pre-existing conditions that are related to their profession. Pesticide exposure and dust from tilling and other farm equipment increase agricultural workers’ risk of respiratory illness. Chronic obstructive pulmonary disease is another lung condition associated with farm work.16

California regulators recognized the increased risk of occupational exposure to smoke for outdoor workers, like those of agricultural workers, unconditioned warehouse workers, construction workers, and day laborers. In response, California’s Occupational Safety and Health (CalOSHA) enacted an emergency wildfire smoke standard when the Air Quality Index (AQI) for particulate matter 2.5 micrometers or smaller (PM2.5) is 151 or greater.17 

When air quality reaches 151 to 500, employers must provide approved respirators to employees. At minimum, employers must increase the number of rest periods for workers, if relocation and/or rescheduling are unfeasible. When the AQI exceeds 500, respirators are required to be used by the employees.  The regulation also requires employers to provide training on health issues like the effects of a smoke event and the proper use of a respirator.

Such regulations are a critical first step in reducing the negative effects of the occupational SDOHs that agricultural workers are facing as the climate crisis deepens, and as the climate crisis is overlayed with other disasters, such as the coronavirus pandemic. In 2020, researchers linked wildfire smoke to thousands of additional COVID-19 cases and deaths.18 Agricultural workers continue to be at a high risk for COVID-19 exposure and illness due to their determinants of health like low economic stability, substandard housing, and poor access to health care and health education. Many agricultural workers who contracted a COVID-19 infection at work found themselves battling the virus with reduced lung function due to ongoing smoke exposure. Such workers may struggle to isolate themselves from family members or other workers in crowded housing, may be unable to easily access or afford sufficient health care, and may not have financial security to leave work for a period of time. This demonstrates that overlapping crises may magnify the negative determinants that workers like agricultural workers face.

In August 2021, Washington followed California’s lead and implemented its own emergency standard on wildfire smoke. As of September 2021, while many states across the US are experiencing significant wildfires, California and Washington remain the only states with a smoke standard, leaving hundreds of thousands of outdoor workers and indoor workers in unconditioned warehouses unprotected.


Of course, the most notable direct impact of climate change is increased temperatures. According to the CDC, agricultural workers’ risk of dying because of heat exposure is 20 to 35 times higher than workers in other industries.19 20 As climate change advances, the health risks accelerate.

Agricultural workers’ risk of heat stress may increase due to their occupational SDOHs: fear of retaliation may prevent them from asking for rest or water breaks. Those who have rest and water breaks available may forgo them, as many are paid a piece rate, which encourages workers to move quickly without breaks. Substandard unconditioned housing result in many workers coming to work already dehydrated, positioning them poorly for the hot day ahead. In one recent study, half of workers started their day dehydrated.21

Some health concerns from climate change overlap. A heat wave may occur during a smoke episode. The cumulative impact of heat and smoke is a new concern among clinicians serving agricultural workers, and is highlighted as a special concern in Clinician’s Guide to Heat Stress, produced by Farmworker Justice and Migrant Clinicians Network, and released earlier this year. The guide notes that the use of personal protective equipment like respirators, to reduce exposure to smoke or pesticides, may also increase a worker’s risk of heat illness.

The guide also highlights chronic kidney disease of nontraditional origin (CKDnt), which may be associated with chronic heat stress. CKDnt is prevalent among agricultural workers in Central America and the success of water/rest/shade interventions in farms there indicate that the CKDnt epidemic among workers is primarily driven by occupational heat stress.22

As the climate crisis increases heat events around the US, workers who work outdoors or in unconditioned warehouses are, once again, at greater health risk because of their unique determinant of health related to their occupation, which are exacerbated in a hotter world.

At present, there is no federal heat standard to protect outdoor workers. California’s heat standard is no longer the only one; Washington, Oregon, and Minnesota have standards (although Minnesota’s only covers indoor workers), and Maryland is presently drafting a standard. However, in September 2021, the White House launched an interagency effort to respond to extreme heat, including an OSHA notice that begins the process of advancing a workplace heat standard.23 


Taken as a whole, marginalized workers are clearly on the frontlines of the climate crisis. Clinicians need additional training to increase awareness about the new and overlapping health concerns that such workers are encountering. Additionally, national strategies to reduce the impact of the climate crisis on such populations need to be adopted. At the federal level, the new Health and Human Services Office of Climate Change and Health Equity does just that, seeking to identify communities with disproportionate exposures to climate hazards and vulnerable populations, addressing health disparities exacerbated by climate impacts, and providing training opportunities to the health workforce, among other important goals.26 Such commitments to health equity, however, must be matched by rapid, worldwide implementation of efforts to reduce the pace of climate change through the reduction of greenhouse gases, if we wish to impactfully lessen the threats to health that climate change currently poses.



Clinician’s Guide to Heat Stress:

“It’s So Hot and It’s Dangerous,” MCN’s webinar on the role of community health workers in preventing heat-related illness, is archived on our website in English:

“¡Hace mucho calor y es peligroso!” The webinar was repeated in Spanish and is archived as well:

“Explorando la salud mental y el impacto de la crisis climática en las comunidades agrícolas,” or “Exploring the mental health and the impact of the climate crisis on agricultural communities,” is another MCN webinar that is archived:

“Why Farmworkers Need More Than New Laws for Protection From Heat-Related Illness,” an article in the Journal of the American Medical Association (JAMA), features MCN’s Amy K. Liebman, Director of Occupational and Environmental Health.

Read MCN’s comments on heat stress and details about what heat standards need to include to protect outdoor worker health, in our September comments to the Maryland Occupational Safety and Health:

Read the IPCC’s executive summary of their Sixth Assessment Report to learn more about the physical changes from climate change:  Watch for the IPCC’s February 2022 report on the impact of these changes on marginalized populations.

MCN is a signatory of Clinicians for Planetary Health. Read more about C4PH’s work and about planetary health:

Read The Lancet’s 2019 issue focused on planetary health, including the health consequences of climate change and environmental change, and the push for global action by clinicians:

The Lancet Countdown, an annual publication of The Lancet focuses on health and climate change from an international and multidisciplinary approach, recently came out with their 2021 report:




1 Masson-Delmotte VP et. al. IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. 7 August 2021. In Press. Available at:

2 Lai S, Sadeque S, and Fisher M. Life and death underground: N.Y. immigrants perish in flooded basements. The Washington Post. 4 September 2021. Available at:

3 Miller B et. al. Hurricanes are becoming more dangerous. Here’s why. CNN. 3 December 2020. Available at:

4 Knutson T. Global Warming and Hurricanes: An Overview of Current Research Results. Geophysical Fluid Dynamics Laboratory. 9 August 2021. Available at:

5 Masson-Delmotte VP et. al. IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. 7 August 2021. In Press. Available at:

6 Gucciardi E, Vahabi M, Norris N, Del Monte JP, Farnum C. The Intersection between Food Insecurity and Diabetes: A Review. Curr Nutr Rep. 2014;3(4):324-332. doi:10.1007/s13668-014-0104-4. Available at:

7 Pan L, Sherry B, Njai R, Blanck HM. Food insecurity is associated with obesity among US adults in 12 states. J Acad Nutr Diet. 2012;112(9):1403-1409. doi:10.1016/j.jand.2012.06.011. Available at:

8 Ramchandani A. Hurricane Season Is Especially Hard for Farmworkers. The Atlantic. 25 September 2018. Available at:

9 Harris A et. al. Microbial Contamination in Environmental Waters of Rural and Agriculturally-Dominated Landscapes Following Hurricane Florence. ACS EST Water. 2021, 1, 9, 2012–2019

 23 August 2021

10 California Department of Industrial Relations. 5141.1 Protection from Wildfire Smoke. Subchapter 7. General Industry Safety Orders. Group 16. Control of Hazardous Substances. Article 107. Dusts, Fumes, Mists, Vapors and Gases. Available at:

11 CalFire. California Wildfires and Acres for all Jurisdictions. 24 August 2020. Available at:

12 CalFire. Stats and Events: Current Year Statistics. Available at:

13 Braxton Little J. Fighting Fire with Fire: California Turns to Prescribed Burning. Yale Environment 360. 5 September 2018. Available at:

14 Agricultural Employment in California. Employment Development Department, State of California. Available at:

15 Costa D, Martin P, and Rutledge Z. Federal labor standards enforcement in agriculture. Economic Policy Institute. 15 December 2020. Available at:

16 Silver SR, Alarcon WA, Li J. Jobs and Exposures That Increase Risk for Developing COPD Later in Life. NIOSH Science Blog. Available at:

17 California Department of Industrial Relations. Worker Protection from Wildfire Smoke. Available at:

18 Wildfire smoke may have contributed to thousands of extra COVID-19 cases and deaths in western U.S. in 2020. Harvard T.H. Chan School of Public Health. 13 August 2021. Available at:

19 Heat-Related Deaths Among Crop Workers --- United States, 1992--2006. Centers for Disease Control and Prevention. 19 June 2008. Available at:

20 Gubernot DM, Anderson GB, Hunting KL. Characterizing occupational heat-related mortality in the United States, 2000-2010: an analysis using the Census of Fatal Occupational Injuries database. Am J Ind Med. 2015;58(2):203-211. doi:10.1002/ajim.22381

21 Mac VV, Tovar-Aguilar JA, Flocks J, Economos E, Hertzberg VS, McCauley LA. Heat Exposure in Central Florida Fernery Workers: Results of a Feasibility Study. J Agromedicine. 2017;22(2):89-99. doi:10.1080/1059924X.2017.1282906.

22 Migrant Clinicians Network. Heat-Related Illness Clinician’s Guide. June 2021. Available at:

23 FACT SHEET: Biden Administration Mobilizes to Protect Workers and Communities from Extreme Heat. White House Briefing Room. 20 September 2021. Available at:

24 Irfan U. Valley Fever on the Rise in U.S. Southwest, with Links to Climate Change. Scientific American. 14 September 2012. Available at:

25 Browne E. What Is Valley Fever and What Are the Symptoms as Cases Rise in Southwest U.S. Newsweek. 27 September 2021. Available at:

26 HHS Establishes Office of Climate Change and Health Equity. US Health and Human Services. 30 August 2021. Available at:


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Associate Director of Communications