January 8, 2021
U.S. Global Change Research Program
Intergovernmental Panel on Climate Change
To Whom It May Concern:
The American College of Occupational and Environmental Medicine is pleased to offer the following comments on Chapter 7: Health, wellbeing, and the changing structure of communities
of the Intergovernmental Panel on Climate Change (IPCC) Working Group II Contribution to the Sixth Assessment Report.
Occupational and envronmental medicine (OEM) is the medical specialty that identifies, prevents, and mitigates adverse effects of hazardous agents and conditions in the workplace and environment. ACOEM is a national medical society representing 4,000 occupational medicine physicians and other health care professionals devoted to promoting optimal health and safety of workers, workplaces, and environments. ACOEM is dedicated to improving the care and well-being of workers through science and the sharing of knowledge. ACOEM and its members are committed to the applications of sound science and rigorous research to improve the lives of the American people and all others around the world.
We applaud the extraordinary work of the IPCC and aim to support the science-based assessment and recommendations through our unique perspective as physicians and other healthcare professionals focused on workers, workplaces, and the environment. We found Chapter 7 to be complete in some areas but lacking in detail in others, in particular those related to worker health and chemical exposure. We focus our comments on these areas but wish to clarify that our overall assessment of Chapter 7 is positive.
The following are locations in the Chapter where we recommend work and workers health be included:
- Executive Summary (7-3 line24), Labour capacity is mentioned in line 21, but workers will be affected beyond their “capacity.” We recommend including this sentence “Outdoor workers and emergency workers are also likely to experience disproportionate adverse health impacts in association with their work-related exposure to extreme weather and climate events.”
- Executive Summary (7-3 line 55-57) In its current form, this point is vague and we recommend inserting ‘including loss of work and displacement’ after temperatures in this sentence. These are two important drivers of mental health impact as described later in the document.
- Executive Summary (7-5 line 43-44) We support the statement about gender equality work. However, it seems a missed opportunity to not simply state “Educating girls through puberty has been shown to have a robust impact on their health, the health of their families and improved climate change metrics.” This point is made clearly in the adaptation section and deserves to be in the executive summary considering the large number of people affected and the large impact of the solution.
- 7.1.6 (7-10 line 6-10) ‘‘work availability” is a very important indirect pathway that should be inserted in this sentence.
- Table CCB COVID.1: Pathways, synergies and trade-offs between pandemic responses and climate responses. Under Risk Reduction, we recommend an additional category of “Occupational vulnerabilities” (Moda et al., 2019). In the adjacent box for Pandemic responses including COVID-19 action, we recommend “Assessment of unique vulnerabilities of occupational populations and provision of education regarding risk reduction and personal protective equipment.” In the adjacent box, “Reducing the risk of exposure to COVID-19 at work through education and the proper use of personal protective equipment will enhance health resilience to other climate related exposures through a better informed and equipped worker population.”
- 220.127.116.11 Cardiovascular diseases (7-25 line 47-50) Wildfire firefighters generally use no respiratory personal protective equipment. Despite their work outside, their exposures can be significant and their cumulative lifetime exposure to particulates and carbon monoxide, known drivers of cardiovascular disease, and human carcinogens will increase with climate change and increased time fighting fires. A recent study by Navarro modeled exposure to wildfire smoke among firefighters. Even working just 49 days/year for only 5 years increased cardiovascular disease risk by 16% and lung cancer by 8%. We recommend that this section incorporate this biologically plausible risk to a vulnerable occupational population.
- 7-27 line 38-40 “socio-economic vulnerability” does not adequately include the occupational constraints that some outdoor workers experience that put them at increased risk for extreme heat related medical conditions. We recommend adding ‘occupational constraints’ after socio-economic vulnerability.
- 7-28 line 19 This section does not acknowledge the impact of adverse birth outcomes due to air pollution. We recommend the following sentence ‘ Air pollution, expected to increase in some places due to extremes in weather conditions, has been associated with adverse birth outcomes (Lavigne et al., 2016). Outdoor workers who are pregnant would be particularly vulnerable.’
- 7-29 line 50 It is important to acknowledge the unique vulnerability of certain outside workers to impacts on mental health. We recommend including after structural inequities “or lack of control over one’s environment such as experienced by some outside workers” (Hanna et al., 2011).
The following are locations in the chapter where we recommend the consideration of health impacts from chemical exposure be expanded:
- Executive Summary (7-3 line 34-41), Cancer should be included in this section. Increased energy use will increase air pollution, an IARC determined known human carcinogen. In addition, in regions that will experience less rainfall, ultraviolet radiation exposure will increase leading to more skin cancer.
- 7.1.5 (7-9 line 28-29) the phrase “linkages between indicators of health, wellbeing and environmental impacts from climate change remain patchy” understates the current situation of siloed knowledge. We recommend “A comprehensive framework that fully integrates health, wellbeing and environmental impacts from climate change allowing for the cumulative assessment of their impact is not in place.”
- Table Box 7.2.1: Pathways between climate hazard and waterborne disease outcomes, we recommend adding “and chemicals” to Storm runoff mobilizes and transports pathogens.
- 18.104.22.168 Observed impacts on other risks in food chain should include the inorganic, organic and radiologic contaminants that will also be impacted by climate change storm surge, concentrated rain events and flooding. Strong seasonal variations in precipitation found in ecosystems like the Amazon reveal contamination of fish that may be expected to occur in other areas as the climate changes. Mercury levels in fish are higher in the Brazilian Amazon during the water rising season, when runoff is occurring, increasing the risk for populations relying on the consumption of fish (Azevedo, 2019). Microplastics were found to increase 14-fold after multiple floods in the Mersin Bay of the Mediterranean in Turkey between 2016 and 2017 (Gündoğdu, 2018). Multiple species of crustaceans and swimming fish in the Mediterranean Sea used for human consumption have been found to contain microplastics (Llorca et al., 2020). This is an emerging problem for human health that climate change is expected to worsen with increasing flooding.
- We recommend the addition of the following to the end of the paragraph ( 7-24 line 19), “Although the literature on quantifiable health impacts due to increased chemical exposure due to climate change may currently be less than robust , environmental health scientists have long identified this risk and urged enhanced attention to it (Balbus et al., 2013). More recently, scientists have identified key gaps in the calculation of the global burden of disease due to environmental health factors (Shaffer, 2019).”
- 7-25, line 8. We recommend the addition of a section: Burden of chemical toxicant exposure may increase due to climate change. In the United States where a process exists to characterize sites containing hazardous materials, estimates of potential contaminant redistribution considering cities with >100,000 population only, reveal 712 US census tracts with a high flood probability and a known site of hazardous chemicals (Marcantonio, 2019). Hurricanes Sandy and Harvey led to the redistribution of toxic materials in New York and Houston (Kiaghadi, 2019, Mandigo, 2016). These materials were not exclusively derived from legacy waste sites, but also from off-site migration due to flooding of chemical contaminants from currently operating manufacturing and processing plants. Extrapolating these risks globally should warrant further discussion and consideration of proactive measures. Flood waters that enter homes have been shown to carry chemical contaminants that have health impacts (Eurididou, 2004). Flooding can cause waste water from storage tanks and containment dikes to overflow and contaminate the surrounding community including drinking water sources (Cruz and Krausman, 2013). Coal ash impoundments have been shown to spill into waterways near them during hurricanes depositing heavy metals in concentrations higher than ecological screening standards. A large number of impoundments exist in the southeastern US in areas vulnerable to flooding (Vengosh et al., 2019). Winds and flooding as a result of increasing intensity and frequency of storms can also disrupt pipelines and ground transportation systems causing further exposure to hazardous substances in nearby communities. A 2019 review by Erickson describes the toxic effects of floods and storms.
- 22.214.171.124 Cancer. We find this section to be particularly brief, such that it does not convey enough information to be useful to readers. We recommend the inclusion of some pathway examples that will elucidate the cumulative exposure pathways that are likely to occur with increasing climate change. Flood plains around the world reveal the mobility of industrial chemicals. In Spain, sediments in the Mar Menor lagoon revealed increased levels of polychlorinated biphenyls (PCBs) in zones where runoff came from industrial and urban areas (Leon et al., 2015). Studies in the Philippines after a large flood in 2009 revealed that the high flood water flow in main river tributaries resulted in the purging of PCB contaminated sediments into Laguna Lake (Santiago et al., 2012). PCBs are ubiquitous in the global environment. They are persistent and bioaccumulate. Some PCBs are carcinogenic to humans as determined by the International Agency for Research on Cancer. This determination was driven by the clear evidence in humans of increased rates of malignant melanoma in occupational and general populations with increasing serum levels of PCBs (Lauby-Secretan, 2013). Climate change may increase the risk for malignant melanoma through two mechanisms, increasing ultraviolet radiation and increasing exposure to PCBs in food. Outdoor workers are particularly vulnerable to skin cancer due to enhanced solar radiation in areas with decreasing precipitation (Modenese, 2018). Wildfires will increase the burning of buildings and other structures in some areas which has been shown to routinely produce carcinogens such as benzene while burning which continue to be emitted long after extinguishment of the fire (Lam et al., 2019). Numerous other carcinogens may be emitted in fires depending on the construction and building content materials.
- 7-50 line 24. We recommend the inclusion of the following in this section “About half of the world’s population uses surface water as their drinking water source. The WHO-UNICEF Joint Monitoring Programme on Water Supply and Sanitation considers surface waters ‘not improved drinking water sources.” The impacts of flooding on surface water used for drinking water are related to the ground over which the flooding has occurred. Studies of fluvial floods in Australia reveal high heavy metal deposition in sediment deposited from overland runoff and direct urban stormwater discharge (Lintern et al., 2016). Flood plains around the world reveal the mobility of agricultural pesticides and industrial chemicals, some of which are endocrine disrupting chemicals, neurotoxins, and/or carcinogens. In Cameroon, 30 pesticides with 17 active ingredients were identified in flood waters (Fai et al., 2019). In Spain, sediments in the Mar Menor lagoon revealed increased levels of organochlorine pesticides (e.g., DDE, DDD) in zones near agricultural runoff and polychlorinated biphenyls (PCBs) in zones where runoff came from industrial and urban areas (Leon et al., 2015). Use of these contaminated waters as drinking water sources would increase exposure to these biologically active chemicals.
We appreciate the opportunity to submit these comments for your review and would be pleased to answer questions or provide additional input as needed. Thank you.
Beth A. Baker, MD, MPH, FACOEM