By Paul Roberts / For The Herald
Publications on global warming and climate change understandably focus on greenhouse gas emissions, global temperatures, heat, extreme weather events, fires, droughts and sea level rise. Sometimes, the effects on human health are overshadowed by these larger events. Yet, we don’t live in the global climate, we live in communities affected by it. Impacts and risks to human health depend on where we live and shape our experience and perception of climate change.
Of the health risks posed by climate change, extreme heat is by far the most lethal. When our body cannot maintain a stable temperature the result is heat exhaustion, heatstroke and ultimately death (see Eco-Nomics No. 3, Aug. 19,). A warmer world facilitates migration of diseases by the vectors that carry them to new areas, exposing new populations (viruses such as malaria, dengue, chikungunya and West Nile, etc.). Severe weather, floods and fires pose risks of injuries, fatalities and mental health issues associated with displacement.
But the greatest number of people worldwide — and in the Pacific Northwest — are affected by air pollution resulting from fossil fuel exhaust, wildfire smoke and airborne dust. The result is increases in asthma, cardiovascular disease, allergies, chronic obstructive pulmonary disease and exposure to known carcinogens.
Pollution from fossil fuel exhaust is concentrated along major road, rail and shipping corridors ailing those living in close proximity. Poor air quality disproportionately impacts poor and elderly individuals. In Everett, the convergence of I-5, U.S. 2, BNSF’s rail mainline and port facilities all contribute to diminished air quality.
Under federal and state laws, the Environmental Protection Agency, state Department of Ecology and the Puget Sound Clean Air Agency coordinate responsibilities regulating pollution and air quality. This includes six criteria pollutants designated by the EPA under the Clean Air Act: particulates, ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide and lead. These pollutants are the nasty cousins that travel with greenhouse gaes, resulting from burning fossil fuels and wildfires.
These pollutants are ubiquitous, though they are concentrated more in areas near pollution sources or where geography increases concentration. Breathing is not a choice, so it is difficult or impossible to avoid exposure, particularly when the source is wildfire smoke.
The state Ecology Department recently released a report on air quality in Washington state. It found air quality to be poor in some parts of the state including Everett (see Seattle Times and Daily Herald, Jan. 3). Across Washington an estimated 728 deaths were attributabed to air pollution in 2019, according to an analysis by the University of Washington’s Institute for Health Metrics and Evaluation.
In the Puget Sound region, fine particulates and ozone pollution likely pose the greatest health risk and are of greatest concern.
Ozone in the lower atmosphere (not to be confused with ozone in the stratosphere that absorbs UV rays) is a component of smog. It is formed through chemical reactions when contaminants from fossil fuels, industrial pollution and volatile organic compounds interact with sunlight. These gases literally cook in sunlight, forming ozone, and are often concentrated in metropolitan areas during warmer weather. In the Puget Sound region, ozone concentrations may be higher in the foothills of the Cascades where pollution can be trapped or suspended by prevailing winds and geography.
Ozone is a powerful oxidant, comparable to household bleach, and can kill living cells on contact. This includes the lining of the lungs and respiratory tract, causing inflammation and irritation, resulting in symptoms such as coughing, chest tightness and worsening asthma. In addition, ozone causes damage to crops, forests and native plants.
Fine particles less than 10 micrometers in diameter contain tiny specks of pollution. The most hazardous particles are less than 2.5 micrometers, noted as PM2.5. By comparison, the average human hair is about 70 micrometers in diameter.
These particles travel deep inside the lungs and can cross the blood barrier entering the blood stream. They cause an inflammatory response throughout the body. They come in many sizes and shapes and can comprise hundreds of different chemicals.
Sources of these tiny particles vary, however the two most common are exhaust from burning fossil fuels — particularly diesel exhaust — and wildfire smoke. Diesel exhaust is a constant source of PM2.5 pollution. Everett’s air quality was determined to be poor due in part to PM2.5 exposure along congested highways and rail facilities.
Wildfire smoke has emerged as a chronic source of air pollution, including PM2.5. Climate change is extending the wildfire season, and the frequency and intensity of wildfires. In recent years, wildfires across the U.S. and Canada have driven air quality indexes to unhealthy levels. People and workers cannot always find refuge from wildfire smoke. The Puget Sound Clean Air Agency monitors smoke and air quality, issuing real time alerts regarding health risks.
The health and economic impacts of these events is only beginning to be measured. Air pollution from wildfires is emerging as one of the greatest risks to health associated with a warming world.
Consumption of fossil fuels increases air pollution and wildfires as well as other risks to human health. These in turn significantly increase costs for health care and the broader economy. The most effective response is to reduce fossil fuel consumption as quickly as possible.
Paul Roberts is retired and lives in Everett. His career spans over five decades in infrastructure, economics and environmental policy including advising Washington cities on climate change and past chair of the Puget Sound Clean Air Agency board of directors.
Eco-nomics
Eco-nomics is a series of articles exploring issues at the intersection of climate change and economics. Climate change (global warming) is caused by greenhouse gas emissions — carbon dioxide and methane chiefly — generated by human activities, primarily burning fossil fuels and agricultural practices. Global warming poses an existential threat to the planet. Successfully responding to this threat requires urgent actions — clear plans and actionable strategies — to rapidly reduce GHG emissions and adapt to climate-influenced events.
The Eco-nomics series, to be published every other week in The Herald, is focusing on mitigation and adaptation strategies viewed through the twin perspectives of science and economics.
Find links to the series thus far at tinyurl.com/HeraldEco-nomics.
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