Reductions in air pollution yielded fast and dramatic impacts on health-outcomes

Reductions in air pollution yielded fast and dramatic impacts on health-outcomes, as well as decreases in all-cause morbidity, according to findings in “Health Benefits of Air Pollution Reduction,” new research published in the American Thoracic Society’s journal, Annals of the American Thoracic Society.

The study by the Environmental Committee of the Forum of International Respiratory Societies (FIRS) reviewed interventions that have reduced air pollution at its source. It looked for outcomes and time to achieve those outcomes in several settings, finding that the improvements in health were striking. Starting at week one of a ban on smoking in Ireland, for example, there was a 13 percent drop in all-cause mortality, a 26 percent reduction in ischemic heart disease, a 32 percent reduction in stroke, and a 38 percent reduction in chronic obstructive pulmonary disease (COPD). Interestingly, the greatest benefits in that case occurred among non-smokers.

“We knew there were benefits from pollution control, but the magnitude and relatively short time duration to accomplish them were impressive,” said lead author of the report, Dean Schraufnagel, MD, ATSF. “Our findings indicate almost immediate and substantial effects on health outcomes followed reduced exposure to air pollution. It’s critical that governments adopt and enforce WHO guidelines for air pollution immediately.”

In the United States, a 13-month closure of a steel mill in Utah resulted in reducing hospitalizations for pneumonia, pleurisy, bronchitis and asthma by half. School absenteeism decreased by 40 percent, and daily mortality fell by 16 percent for every 100 ?g/m3 PM10 (a pollutant) decrease. Women who were pregnant during the mill closing were less likely to have premature births.

A 17-day “transportation strategy,” in Atlanta, Georgia during the 1996 Olympic Games involved closing parts of the city to help athletes make it to their events on time, but also greatly decreased air pollution. In the following four weeks, children’s visits for asthma to clinics dropped by more than 40 percent and trips to emergency departments by 11 percent. Hospitalizations for asthma decreased by 19 percent. Similarly, when China imposed factory and travel restrictions for the Beijing Olympics, lung function improved within two months, with fewer asthma-related physician visits and less cardiovascular mortality.

In addition to city-wide polices, reducing air pollution within the home also led to health benefits. In Nigeria, families who had clean cook stoves that reduced indoor air pollution during a nine-month pregnancy term saw higher birthweights, greater gestational age at delivery, and less perinatal mortality.

The report also examines the impact of environmental policies economically. It highlights that 25 years after enactment of the Clean Air Act, the U.S. EPA estimated that the health benefits exceeded the cost by 32:1, saving 2 trillion dollars, and has been heralded as one of the most effective public health policies of all time in the United States. Emissions of the major pollutants (particulate matter [PM], sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, and lead) were reduced by 73 percent between 1990 and 2015 while the U.S. gross domestic product grew by more than 250 percent.

Given these findings, Dr. Schraufnagel has hope. “Air pollution is largely an avoidable health risk that affects everyone. Urban growth, expanding industrialization, global warming, and new knowledge of the harm of air pollution raise the degree of urgency for pollution control and stress the consequences of inaction,” he says. “Fortunately, reducing air pollution can result in prompt and substantial health gains. Sweeping policies affecting a whole country can reduce all-cause mortality within weeks. Local programs, such as reducing traffic, have also promptly improved many health measures.”

Story Source:

Materials provided by American Thoracic SocietyNote: Content may be edited for style and length.

Journal Reference:

  1. Dean E. Schraufnagel, John R. Balmes, Sara De Matteis, Barbara Hoffman, Woo Jin Kim, Rogelio Perez-Padilla, Mary Rice, Akshay Sood, Aneesa Vanker, Donald J. Wuebbles. Health Benefits of Air Pollution ReductionAnnals of the American Thoracic Society, 2019; 16 (12): 1478 DOI: 10.1513/AnnalsATS.201907-538CME

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American Thoracic Society. “Dramatic health benefits following air pollution reduction.” ScienceDaily. ScienceDaily, 6 December 2019. <>.


Living in a more polluted area is associated with a greater likelihood of having glaucoma, a debilitating eye condition that can cause blindness, finds a new UCL-led study in the UK.

People in neighbourhoods with higher amounts of fine particulate matter pollution were at least 6% more likely to report having glaucoma than those in the least-polluted areas, according to the findings published in Investigative Ophthalmology & Visual Science.

“We have found yet another reason why air pollution should be addressed as a public health priority, and that avoiding sources of air pollution could be worthwhile for eye health alongside other health concerns,” said the study’s lead author, Professor Paul Foster (UCL Institute of Ophthalmology and Moorfields Eye Hospital).

“While we cannot confirm yet that the association is causal, we hope to continue our research to determine whether air pollution does indeed cause glaucoma, and to find out if there are any avoidance strategies that could help people reduce their exposure to air pollution to mitigate the health risks.”

Glaucoma is the leading global cause of irreversible blindness and affects over 60 million people worldwide. It most commonly results from a build-up of pressure from fluid in the eye, causing damage to the optic nerve that connects the eye to the brain. Glaucoma is a neurodegenerative disease.

“Most risk factors for glaucoma are out of our control, such as older age or genetics. It’s promising that we may have now identified a second risk factor for glaucoma, after eye pressure, that can be modified by lifestyle, treatment or policy changes,” added Professor Foster.

The findings were based on 111,370 participants of the UK Biobank study cohort, who underwent eye tests from 2006 to 2010 at sites across Britain. The participants were asked whether they had glaucoma, and they underwent ocular testing to measure intraocular pressure, and spectral-domain optical coherence tomography imaging (a laser scan of the retina) to measure thickness of their eye’s macula (central area of the retina).

The participants’ data was linked to air pollution measures for their home addresses, from the Small Area Health Statistics Unit, with the researchers focusing on fine particulate matter (equal or less than 2.5 micrometres in diameter, or PM2.5).

The research team found that people in the most-polluted 25% of areas were at least 6% more likely to report having glaucoma than those in the least-polluted quartile, and they were also significantly more likely to have a thinner retina, one of the changes typical of glaucoma progression. Eye pressure was not associated with air pollution, which the researchers say suggests that air pollution may affect glaucoma risk through a different mechanism.

“Air pollution may be contributing to glaucoma due to the constriction of blood vessels, which ties into air pollution’s links to an increased risk of heart problems. Another possibility is that particulates may have a direct toxic effect damaging the nervous system and contributing to inflammation,” said the study’s first author, Dr Sharon Chua (UCL Institute of Ophthalmology and Moorfields Eye Hospital).

Air pollution has been implicated in elevated risk of pulmonary and cardiovascular disease as well as brain conditions such as Alzheimer’s disease, Parkinson’s disease and stroke. Particulate matter exposure is one of the strongest predictors of mortality among air pollutants.

This study adds to previous evidence that people in urban areas are 50% more likely to have glaucoma than those in rural areas, suggesting now that air pollution may be a key contributor to that pattern.

“We found a striking correlation between particulate matter exposure and glaucoma. Given that this was in the UK, which has relatively low particulate matter pollution on the global scale, glaucoma may be even more strongly impacted by air pollution elsewhere in the world. And as we did not include indoor air pollution and workplace exposure in our analysis, the real effect may be even greater,” said Professor Foster.


Breathing dirty air can make you sick. But according to new research, it can also make you more aggressive.

That’s the conclusion from a set of studies recently authored by Colorado State University researchers in economics, atmospheric science and statistics. Together, the team found strong links between short-term exposure to air pollution and aggressive behavior, in the form of aggravated assaults and other violent crimes across the continental United States.

The results, derived from daily Federal Bureau of Investigation crime statistics and an eight-year, detailed map of daily U.S. air pollution, will be published in a forthcoming edition of the Journal of Environmental Economics and Management.

The paper’s lead author is Jesse Burkhardt, assistant professor in the Department of Agricultural and Resource Economics, who teamed up with fellow economist Jude Bayham in the same department; Ander Wilson in the Department of Statistics; and several air pollution experts in civil engineering and atmospheric science.

The CSU researchers cross-analyzed three highly detailed datasets: daily criminal activity from the National Incident-Based Reporting System managed by the FBI; daily, county-level air pollution from 2006-2013 collected by U.S. Environmental Protection Agency monitors; and daily data on wildfire smoke plumes from satellite imagery provided by the National Oceanic and Atmospheric Administration’s Hazard Mapping System.

Air pollution scientists typically measure rates of pollution through concentrations of ozone, as well as of “PM2.5,” or breathable particulate matter 2.5 microns in diameter or smaller, which has documented associations with health effects.

Eighty-three percent of crimes considered “violent” by the FBI are categorized as assaults in crime databases. In the researchers’ study, they observed whether crimes occurred inside or outside the home; they found that 56 percent of violent crimes and 60 percent of assaults occurred within the home, which is an indication that many such crimes are tied to domestic violence.

The research results show a 10 microgram-per-cubic-meter increase in same-day exposure to PM2.5 is associated with a 1.4% increase in violent crimes, nearly all of which is driven by crimes categorized as assaults. Researchers also found that a 0.01 parts-per-million increase in same-day exposure to ozone is associated with a 0.97% increase in violent crime, or a 1.15% increase in assaults. Changes in these air pollution measures had no statistically significant effect on any other category of crime.

“We’re talking about crimes that might not even be physical — you can assault someone verbally,” co-author Bayham said. “The story is, when you’re exposed to more pollution, you become marginally more aggressive, so those altercations — some things that may not have escalated — do escalate.”

The researchers made no claims on the physiological, mechanistic relationship of how exposure to pollution leads someone to become more aggressive; their results only show a strong correlative relationship between such crimes and levels of air pollution.

The researchers were careful to correct for other possible explanations, including weather, heat waves, precipitation, or more general, county-specific confounding factors.

The team published a companion paper in the Journal of Environmental Economics and Policy with similar results that used monthly crime statistics. A third paper in Epidemiology, with lead author Jesse Berman at University of Minnesota and co-authors from CSU, used EPA pollution monitor databases and different statistical techniques and came to similar conclusions.

The tool that allowed the team to overlay crime data with pollution data was originally used in collaboration with CSU epidemiologist Sheryl Magazmen to study health effects from air pollution, explained co-author Jeff Pierce, associate professor in the Department of Atmospheric Science and a Monfort Professor. Pierce, associate professor Emily Fischer and researchers Kate O’Dell and Bonne Ford, had previously worked with Magzamen to detail how smoke and particulate matter exposure correlated with things like hospitalizations and asthma inhaler refills.

Burkhardt had been wanting to study whether breathing smoke could enact behavioral change when he met atmopsheric scientist Pierce.

“Several years ago, Fort Collins experienced a fairly severe wildfire season,” Burkhardt said. “The smoke was so bad that after a few days, I started to get frustrated, and I wondered if frustration and aggression would show up in aggregate crime data.”

Pierce recognized that the pollution-concentration product he and colleagues had designed, which provided detailed concentrations of total particulate matter and the fraction from smoke, would be useful for Burkhardt’s desired application.

“The results are fascinating, and also scary,” Pierce said. “When you have more air pollution, this specific type of crime, domestic violent crime in particular, increases quite significantly.”

The economists calculated that a 10 percent reduction in daily PM2.5 could save $1.1 million in crime costs per year, which they called a “previously overlooked cost associated with pollution.”

The authors remain interested in the relationships between pollution and cognitive outcomes, Burkhardt said. They are now working with a large online chess platform to determine if increased pollution exposure is correlated with worse chess performance.

The results are just one outcome of CSU’s philosophy around “cluster hiring” faculty from disparate fields to study interdisciplinary problems. In this case, several of the researchers came to CSU under the Partnership for Air Quality, Climate and Health initiative launched several years ago by the Office of the Vice President for Research.

Jesse Burkhardt, Jude Bayham, Ander Wilson, Ellison Carter, Jesse D. Berman, Katelyn O’Dell, Bonne Ford, Emily V. Fischer, Jeffrey R. Pierce. The effect of pollution on crime: Evidence from data on particulate matter and ozoneJournal of Environmental Economics and Management, 2019; 102267 DOI: 10.1016/j.jeem.2019.102267

Colorado State University. “Exposure to air pollution increases violent crime rates.” ScienceDaily. ScienceDaily, 3 October 2019. <>.