Opinion: What the 20th-century war on smog tells us about today’s wildfire smoke

OpinionFirst Opinion What the 20th century war on smog tells us about today’s wildfire smoke The evolution of air pollution policy shows how to respond to the dangerous haze Manage alerts for this article Email this article Share this article By Rebecca Florsheim, Neil Vora, Peter J. Winch, and Connie HoeJuly 17, 2026 Florsheim is an environmental health physician at the NYU Grossman School of Medicine. Vora is a physician and executive director of Preventing Pandemics at the Source. Winch develops and evaluates interventions to promote health behaviors for water, sanitation, infectious diseases, and environmental sustainability. Hoe is a public health researcher who serves as endowed division head for policy and implementation research at the German Cancer Research Center. As wildfires burn millions of acres across Canada, smoke has descended upon cities across the United States, with air quality plummeting to unhealthy levels. In New York City, emergency room visits for asthma exacerbations jumped by 31% by the end of the first day. The timing could not have been worse for a city already in the throes of the second major heat wave of the season. Extreme weather events represent the cyclical and compounding relationship between fossil fuel combustion, a warming climate, natural disasters, and related illnesses. Some may view them as proof the climate crisis has already become insurmountable. However, history teaches us to never let a health-related environmental crisis go to waste.Advertisement Take, for example, the case of air pollution. In the post-World War II era — long before the possibility of a warming climate had even entered the popular imagination — industrialized cities faced a related and similarly overwhelming environmental challenge: air pollution. Regulations for air quality were virtually nonexistent. Garbage was often incinerated rather than transported to landfills. Proliferation of automobiles and coal as an energy source combined with an absence of meaningful emission standards caused dangerously polluted air. Smoke and soot sediment were ubiquitous, with soot often piling up on cars and windowsills. It was known that specific components of air pollution — namely, carbon monoxide, particulate matter, ground-level ozone, sulfur dioxide and nitrogen dioxide, now termed “classical air pollutants” by the World Health Organization or “criteria air pollutants” by the United States Environmental Protection Agency — each had specific associated health risks determined by their chemical properties. Despite this, effective regulations remained elusive for decades. The tipping point for meaningful regulation was finally reached only after cities around the world experienced increasingly severe smog events caused by air pollutants becoming trapped by stagnant atmospheric conditions. The air bronzed, and significant percentages of city dwellers would suddenly fall ill — mostly due to lung or heart conditions — or die. The Great Smog of London in 1952, for example, lasted five days. It caused tens of thousands of illnesses and ultimately 12,000 deaths. It directly led to the passage of the Clean Air Act of 1956 curbing industrial emissions in the United Kingdom.Advertisement In November 1966, New York City also experienced its most alarming smog on record. As levels of sulfur dioxide and carbon monoxide skyrocketed, for the first time, emergency messaging directly appealed to citizens via television, radio, and print media to reduce energy consumption and automobile use. People with pre-existing heart or lung conditions were urged to stay indoors. As municipal incineration services shut down, garbage piled up throughout the city. The irritating and inflammatory nature of the smog caused hundreds of thousands of New Yorkers to become short of breath or to develop symptoms from underlying heart disease. Approximately 200 people died. The tragedy galvanized public demand for environmental stewardship, and legislative response was swift. Within one month, New York City administrative code was updated to expand air pollution surveillance and stifle emissions. Extensive media coverage resonated with vulnerable urbanites across the country. Just two months later, U.S. President Lyndon B. Johnson delivered a landmark special message to Congress, “Protecting Our National Heritage,” specifically referencing the smog event and advocating for the 1967 Air Quality Act enforcing air pollution abatement procedures. The act was passed, followed in 1970 by the Clean Air Act establishing National Ambient Air Quality Standards for smog- and illness-inducing criteria air pollutants. By 2020, as a result of this legislation and its amendments, collective criteria pollutant levels dropped by 78% from 1970 levels (individual pollutant levels dropped as much as 91%), and local emissions no longer cause smog events in the United States. Criteria air pollutants are distinct yet inexorably linked to the greenhouse gases — among them carbon dioxide, methane, nitrous oxide, and tropospheric ozone — now warming our planet. Both result from the combustion processes so ubiquitous in modern life, but the risks they pose occur by different pathways. Criteria air pollutants directly cause illnesses like sinus inflammation, lung and heart disease, cancers, and premature death because of how their physical properties interact with the human body. Excess greenhouse gas emissions generally cause illness less directly by contributing to the climate crisis. A warming climate causes disease and premature death in a number of ways — among them, injuries during extreme weather events, increases in allergen-inducing pollen, smoke from wildfires, and the emergence of infectious diseases.Advertisement More than 50 years after the passage of Clean Air Acts, another one of our most pressing environmental crises is now impossible to ignore. Much like the smog events of the past century did for the problem of local air pollution, the increasing frequency and severity of natural disasters — wildfires, hurricanes, floods, heat waves and droughts — has promoted climate change from an abstract threat to a tangible phenomenon for hundreds of millions of people. Even for those not directly affected by these catastrophes, the indirect effects — a migrating haze from Canada descending on metropolises across the United States, as one example — are now palpable. And the science shows this is useful. Pew Research Center reporting indicates 67% of individuals across 25 countries now view climate change as a major threat. More than 80% who experience extreme weather recognize climate change as a contributing factor. In fact, research shows those who personally endure extreme weather events are more than twice as likely to view climate change as a crisis compared to those who have not. . Every extreme weather event and its true underlying root cause must be brought to the forefront of public discussions. Highlighting health risks related to extreme weather events and their costs is a particularly important opportunity to engage and motivate those who may be less trusting of climate science. The link to these effects must be emphasized clearly, efficiently, and unapologetically. Every time. If we make and follow through on this commitment, this moment in history could be notable not only for alarming escalations in environmental disasters fueled by a changing climate, but for how we used them to ultimately secure our sustainable future. Rebecca Florsheim is an environmental health physician at the NYU Grossman School of Medicine. Neil Vora is a physician and executive director of Preventing Pandemics at the Source. Peter J. Winch, M.D., M.P.H., develops and evaluates interventions to promote health behaviors for water, sanitation, infectious diseases, and environmental sustainability. Connie Hoe is a public health researcher who serves as endowed division head for policy and implementation research at the German Cancer Research Center and as adjunct associate professor at the Johns Hopkins Bloomberg School of Public Health.Advertisement Letter to the editor Have an opinion on this essay? 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