Rice University analysis of state efforts show dramatic gains in reducing airborne particulate matter
National efforts in the last decade to clear the air of dangerous particulate matter have been so successful that most urban areas have already attained the next benchmark, according to new research by Rice University.
Atmospheric researchers at Rice studied the state implementation plans (SIPs) from 23 regions mandated by the Environmental Protection Agency to reduce particulate matter (PM) smaller than 2.5 microns (PM 2.5) to less than 15 micrograms per cubic meter by 2009.
The Rice analysis appears this week in the Journal of the Air and Waste Management Association.
All but one of the regions studied reported they had met the goal by deadline. States with regions that met the deadline included Connecticut, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee and West Virginia, as well as the District of Columbia. The final region, Alabama, reported attainment in 2010.
PM 2.5 concentrations in the nonattainment regions that filed SIPs to attain the standard by 2009 declined by an average 2.6 micrograms per cubic meter – significantly greater improvement than in regions that had attained the standard from its inception. The study showed PM reductions in the SIP regions were broadly spread, rather than pinpointed at the most polluted monitors.
"One of the things we were most interested in looking at was to see if states were cherry-picking their measures to meet the standard by reducing pollution at their worst monitors, compared with how much they were doing to bring down levels all across the region so that people were breathing cleaner air," said Daniel Cohan, an associate professor of civil and environmental engineering at Rice.
"It was encouraging to find that across the country, we have seen overall particulate-matter levels come down. We found very slight extra improvement at monitors that were targeted the most, but regions that had to develop plans achieved pretty solid controls that didn't just pinpoint the worst monitors. And the large populations of these regions benefited."
Cohan and Rice alumna Ran Chen also documented that air pollution continued to decline even after the 2009 standards were met. The majority of the SIP regions had already attained the mandated 2014 goal of 12 micrograms per cubic meter by 2012.
"We've been on a good trajectory," Cohan said. "This demonstrates that the combination of state and federal controls has been substantially improving air quality in the U.S."
Recent stories about the ongoing crisis in Beijing, where PM has reached hazardous levels, and in rapidly industrializing countries such as India set the U.S. efforts in sharp relief, Cohan said. The World Health Organization announced this month that about 7 million people die each year as a result of air pollution exposure.
Particulate matter consists of microscopic particles spewed into the air by vehicles and industry, as well as particles that form from pollutant gases. "Particulate matter is not a chemical, like ozone; it's a category, and it's a real challenge to figure out the origin of those particles," Cohan said. "Are they sulfates or carbons or nitrates? Each of these needs vastly different control approaches to make a difference."
PM also includes natural emissions from plants, volcanoes, forest fires and desert dust and can be blown across states or even continents.
The health community, Cohan said, has long expressed concerns about particulate matter in the atmosphere and determined in the 1990s that PM 2.5 particles can penetrate deeply into the lungs and cause heart attacks, decrease lung function and even cause premature death. The EPA found healthy people could experience symptoms from exposure to elevated levels of particulate matter and set mandates for regions deemed in 1997 to be in "nonattainment" to file cleanup plans and follow through by 2009.
The study was the first to take a comprehensive, retrospective look at the overall effectiveness of SIPs for PM. A previous study by Cohan and alumnus Andrew Pegues conducted similar analysis of progress by states in achieving ozone standards.
The National Science Foundation and the NASA Air Quality Applied Sciences Team funded the research.
Read the abstract at http://www.tandfonline.com/doi/abs/10.1080/10962247.2014.905509#.UzQw71zbQ7Q
This news release can be found online at http://news.rice.edu/2014/03/27/us-clean-air-efforts-stay-on-target/
Follow Rice News and Media Relations via Twitter @RiceUNews
Cohan Research Group: https://cohan.rice.edu
EPA Particulate Matter page: http://epa.gov/air/particlepollution/
Image for download:
The Environmental Protection Agency regulates inhalable particles that can lodge in lung tissue and affect human health. (Credit: EPA)
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is 6.3-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go here.
David Ruth | EurekAlert!
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy