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Newsweek
5 days ago
- Health
- Newsweek
Map Shows States With Highest Levels of Tiny, Toxic Air Pollution
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. California and Oregon are among the U.S. hotspots for dangerous submicron (PM1) air pollution—those with particles less than a micron, or a millionth of a meter wide—according to new research. Researchers at Washington University of St. Louis have been quantifying the amount of submicron particles in the air across the country over the last 25 years. The data, which calculated submicron estimates based on known rations of what makes up PM 2.5 particles (those less than 2.5 microns wide), suggest that many areas in the east of the contiguous U.S. contain hotspots. Because PM1 pollution is much smaller than PM2.5 (and at least six times smaller than human blood cells), it has the potential to lead to even worse health effects, as it is small enough to slip past the body's defenses. Parts of Arizona, California, Idaho, New Mexico, Oregon and Texas all appear to have higher concentrations of submicron particulate matter, shown by darker red areas on the researchers' map, as below. A map of the U.S. showing the concentration of submicron particulate matter, with higher concentrations shown by darker red areas. A map of the U.S. showing the concentration of submicron particulate matter, with higher concentrations shown by darker red areas. Atmospheric Composition Analysis Group Conversely, parts of Colorado, Montana, Utah, and Wyoming appear to have far fewer dark patches on the map, suggesting much lower levels of submicron particulate matter. Parts of Arizona and New Mexico showed high concentration levels in some areas, and much lower levels among other regions of their respective state. Higher concentrations of PM1 were found in major urban and industrial areas and areas affected by wildfires, highlighting the role of combustion sources in producing harmful particles. This contrasts with lower concentrations being prevalent across the arid west. The World Health Organization (WHO) suggests that 99 percent of the global population breathes in air containing high levels of pollutants and exceeds the WHO guidelines. The combined effects of ambient air pollution with household air pollution are associated with 7 million premature deaths every year. Both outdoor and indoor air pollution can cause respiratory diseases, as the small particles are able to get deep into the lungs or potentially even into the bloodstream. Exposure to particle pollution can cause heart attacks, irregular heartbeat, aggravated asthma, decreased lung function, and difficulty breathing, according to the Environmental Protection Agency. According to Chi Li, assistant research professor and first author of the study, the small particles identified tend to come from direct air emissions, such as black carbon particles from diesel engines, or the smoke from wildfires. PM1 can also form through secondary processes however, when sulfur dioxide or nitrogen oxides are spit out through fuel combustion and burning coal, Li noted. The significance of pollution regulation should not be overlooked, as the dataset reveals that PM1 levels dropped sharply from 1998 to 2022, as a result of regulations such as the Clean Air Act of 1970. Newsweek has contacted Li via email for comment. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about air pollution? Let us know via science@ Reference Li, C., Martin, R. V., Donkelaar, A. van, Jimenez, J. L., Zhang, Q., Turner, J. R., Liu, X., Rowe, M., Meng, J., Yu, W., & Thurston, G. D. (2025). Estimates of submicron particulate matter (PM1) concentrations for 1998–2022 across the contiguous USA: Leveraging measurements of PM1 with nationwide PM2·5 component data. The Lancet Planetary Health, 9(6).
Yahoo
7 days ago
- Health
- Yahoo
Scientists track 25 years of submicron air pollution particles across US skies
Air pollution is a serious and often underestimated health threat in the U.S. It is linked to over 50,000 premature deaths each year. Tiny particles in the air, like PM2.5, can get embedded into a person's lungs and bloodstream, leading to chronic heart and lung problems. PM2.5 refers to particulate matter that is smaller than 2.5 micron. While scientists have studied these particles for decades, far less is known about PM1— even smaller at under 1 micron—whose effect on human health could be equally lethal, if not more. A new study from Washington University in St. Louis, published in The Lancet Planetary Health, has mapped 25 years of PM1 air pollution across the United States. The findings offer a starting point for identifying which pollutants regulators should target to improve public health. The research also builds on the university's expertise in satellite sensing and atmospheric modeling. According to Chi Li, research assistant professor at the university's Atmospheric Composition Analysis Group and lead author of the study, the new estimates will help researchers better understand the impact of submicron particles. These tiny particles often come from direct emissions, like black carbon from diesel engines or smoke from wildfires. They can also form indirectly when pollutants such as sulfur dioxide or nitrogen oxides are released from fuel combustion and coal burning. Rather than being made of a single substance, air particles are usually mixtures of various materials layered together. Li noted that larger particles are often dominated by components like mineral dust, which are more difficult to regulate or reduce. The researchers estimated PM1 levels by analyzing the known composition of PM2.5 particles, which include seven main components such as sulfate, nitrate, and mineral dust. By combining these elements, the team was able to calculate PM1 concentrations across the US. The study lays the groundwork for deeper analysis of where these tiny particles tend to concentrate, how they form, and what impacts they have on both human health and the environment. PM1 pollution particles may be more harmful because they can penetrate deeper into the body, slipping past natural defenses. These submicron particles are at least six times smaller than a blood cell. According to Jay Turner, the James McKelvey Professor of Engineering Education and co-author of the study, when the United States Environmental Protection Agency (EPA) first set air quality standards for fine particulate matter in 1997, there was significant debate over whether to regulate PM1 or PM2.5. Due to limited health impact research on PM1 compared to PM2.5, the EPA chose to focus on PM2.5. However, the new dataset revealed encouraging insights: pollution regulation has significantly reduced PM1 levels across the contiguous U.S. from 1998 to 2022, largely due to environmental policies like the Clean Air Act. But this progress has slowed since 2010, mainly because of increasing wildfire activity. Although countries like China have gotten a head start in tracking PM1, U.S. can catch up with the help of this comprehensive nationwide dataset. The next step will entail collaboration with epidemiologists to assess how exposure to these tiny particles relates to various health outcomes.
