Climate Change Impacts on Regional Air Quality Report Just Released by EPA

(Washington, D.C. – April 17, 2009) The U.S. Environmental Protection Agency has released a report on the potential impacts of climate change on regional U.S. air quality. The information contained in the report will enhance our ability as a nation to protect air quality and human health.

The report, “Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground-Level Ozone,” concludes that there is a potential for climate change to make ozone pollution worse in some regions and that future ozone management decisions may need to account for the possible impacts of climate change.

Climate change has the potential to produce increases in ground-level ozone in many regions. Ground-level ozone is formed in the presence of sunlight by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOCs), which are emitted from sources like motor vehicles and industrial facilities. Climate change also could increase the number of days with weather conditions conducive to forming ozone, potentially causing air quality alerts earlier in the spring and later in the fall.

The Global Change Research Program in EPA’s Office of Research and Development led the development of the peer-reviewed report, which was done in partnership with EPA’s Office of Air and Radiation. The report combines the results of new EPA-funded and existing scientific research and acknowledges that uncertainty remains over the specific regional patterns of climate change induced ground-level ozone changes.

More information on the report: http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=203459

More information on EPA Office of Research and Development’s Global Change Research Program: http://www.epa.gov/ord/npd/globalresearch-intro.htm

UN Climate Organization Warns Link Between Pollution, Weather, Climate Impact Health

GENEVA (RPRN)23 March 2009- The United Nations’ World Meteorological Organization says there is a close relationship between weather-climate systems and global pollution. The organization says these relationships also affect people’s health.

The World Meteorological Organization says 90 percent of all natural disasters are related to weather, water and climate events. It says air quality is an important factor as well.

The World Health Organization estimates about two million people die prematurely every year due to air pollution, more than half in developing countries. WHO says declining air quality worsens illnesses and deaths from asthma, heart disease, and lung cancer.

The relationship between climate, weather, air quality and health is the theme of this year’s World Meteorological Day, which is observed Monday.WMO Secretary-General, Michel Jarraud, says the scientific community is becoming increasingly aware of the inter-connection.

“For the air quality, what we are talking about is not only the sort of traditional pollutants as you could imagine them,” he noted. “But, it is also many of the gases, which are the greenhouse gases that are also influencing the quality of the air when they are abundant in the lower atmosphere.”

WMO scientists assess and monitor air pollutants such as ground-level ozone, smog, particulate matter, sulfur dioxide and carbon monoxide. Most of these substances directly result from the industrial, urban and vehicular combustion of fossil fuels.

Jarraud says an analysis of this data enables scientists to better forecast the distribution of potentially harmful pollutants in the atmosphere. He says it is increasingly important to do this analysis in connection with urbanization because more than half of the world population lives in urban areas.

“The pollution issues are even more acute in the big urban areas,” he said. “Something else, which we hope does not happen very often, but which happens from time to time are the accidents which can release huge amounts of chemicals or radioactive-during Chernobyl, the radioactive things. We also provide forecasts in order to predict where these things will go, which are the areas which are the most likely affected.”

WMO says a warming climate can exacerbate air pollution. For example, it says climate change and land use are expected to increase desertification worldwide, increasing the risk of sand and dust storms.

It says climate change models show particle-producing fires will continue to increase in both frequency and intensity with rising global temperatures. Drought also is likely to increase, leading to more fires.

About the author: Voice of America. The Voice of America, which first went on the air in 1942, is a multimedia international broadcasting service funded by the U.S. Government through the Broadcasting Board of Governors.

Long-Term Ozone Exposure Linked to Higher Risk of Death, Finds Nationwide Study

BERKELEY — Long-term exposure to ground-level ozone, a major component of smog, is associated with an increased risk of death from respiratory ailments, according to a new nationwide study led by a researcher at the University of California, Berkeley.

The study, to be published in the March 12 issue of the New England Journal of Medicine, analyzed the risk of death for both ozone and fine particulate matter, two of the most prevalent components of air pollution. The study followed nearly 450,000 people for two decades and covered 96 metropolitan regions in the United States.

A new study finds that long-term exposure to ozone is linked to a higher risk of death from respiratory causes. The researchers found that people living in areas with the highest concentrations of ozone, such as the Los Angeles metropolitan area and California's Central Valley, had a 25 to 30 percent greater annual risk of dying from respiratory diseases compared with people from regions with the lowest levels of the pollutant. Those locations included the Great Plains area and regions near San Francisco and Seattle.

"This is the first time we've been able to connect chronic exposure to ozone, one of the most widespread pollutants in the world, with the risk of death, arguably the most important outcome in health impact studies used to justify air quality regulations," said study lead author Michael Jerrett, UC Berkeley associate professor of environmental health sciences. "Previous research has connected short-term or acute ozone exposure to impaired lung function, aggravated asthma symptoms, increased emergency room visits and hospitalizations, but the impact of long-term exposure to ozone on mortality had not been pinned down until now."

The study found that for every 10 parts-per-billion (ppb) increase in ozone level, there is a 4 percent increase in risk of death from respiratory causes, primarily pneumonia and chronic obstructive pulmonary disease.

"World Health Organization data indicate that about 240,000 people die each year from respiratory causes in the United States," said Jerrett. "Even a 4 percent increase can translate into thousands of excess deaths each year. Globally, some 7.7 million people die from respiratory causes, so worldwide the impact of ozone pollution could be very large."

The findings come a year after the U.S. Environmental Protection Agency (EPA) strengthened its National Ambient Air Quality Standards for ground-level ozone from an annual average of 80 ppb to 75 ppb to reflect growing evidence of the harmful health effects of ozone. A group of leading scientists appointed to advise the EPA had actually recommended stricter health standards for ozone levels - from 60 to 70 ppb.

A month after the EPA released its new standards, a National Research Council report concluded that premature deaths related to ozone exposure of less than 24 hours are more likely among those with pre-existing diseases. The report called for more research on the link between mortality and ozone exposure over a period of weeks and years.

Ozone - gas made up of three oxygen atoms - forms a protective layer from the sun's ultraviolet radiation when located in the Earth's upper atmosphere. However, that same gas is toxic at ground level where it can be breathed by humans. Ground level ozone is formed through a complex chemical reaction in sunlight between nitrogen oxides (NOx), commonly spewed from vehicle exhaust, and industrial factory emissions.

The Intergovernmental Panel on Climate Change considers ground-level ozone, along with carbon dioxide and methane, to be one of the primary greenhouse gases in the Earth's atmosphere.

"Ozone levels outdoors are not always highly correlated to ozone levels indoors, making it difficult to fully evaluate associations between ozone and health outcomes using ambient site monitors," said study co-author C. Arden Pope III, professor of economics at Brigham Young University. "The reality is that most of us spend the majority of our time indoors. But this study suggests that repeated exposures to elevated ozone levels over time have cumulative effects on respiratory health."

The new study analyzed data from 448,850 adults ages 30 and older enrolled in 1982 and 1983 in the American Cancer Society Cancer Prevention Study II.

The researchers correlated the information from that study with data from EPA air pollution monitors while controlling for potentially confounding factors such as a participant's age, race, education, occupational exposures, smoking history and diet. The study also factored in other variables such as unemployment rates in the metropolitan and zip code area levels.

Ozone data were obtained from 1977 through 2000 between the months of April and September. Those months were chosen because ozone levels are typically higher when it's warmer and because insufficient data was available during the cooler months.

Researchers included EPA measurements of fine particulate matter – particles equal to or smaller than 2.5 micrometers in diameter and typically found in smoke and haze – when they became available in 1999 and 2000. Because fine particle levels had already been linked to increased risk of premature death in previous studies, the researchers included them in the analysis to distinguish the effects of the two pollutants.

In an 18-year follow-up period, 48,884 of the people in the study died from cardiovascular causes such as heart disease and strokes, and 9,891 died from respiratory causes.

As has been observed in previous studies, the researchers found that fine particulate matter was linked to an increased risk of death from cardiovascular causes when analyzed alone and with ozone. The new finding was that the effects of ozone remained strongly linked to risk of death from respiratory problems, even after fine particle pollution was taken into account.

Not surprisingly, highly populated regions such as the Los Angeles, Riverside and Houston areas, where the climate is sunny for much of the year and the air mass is relatively stable, had the highest average concentrations of ozone, ranging from 62.5 to 104 ppb. The regions with the lowest ozone levels had average concentrations of 33.3 to 53.1 ppb.

"Places like the Pacific Northwest and the Minneapolis St. Paul region are cooler and see more rain in the summer, which keeps the ozone levels in check," said Jerrett. "Similarly, the San Francisco Bay Area's infamous summertime fog blocks the sun and helps protect the region from high ozone levels."

Because ozone formation depends on a complex interaction of multiple factors, it is challenging to regulate, the study authors said. "Our study for the first time presents evidence suggesting that long-term exposure to ozone and fine particle pollution have separate, independent effects on mortality, and that they seem to impact different parts of the body," said Jerrett. "With this research, we now know that controlling ozone is not only beneficial for mitigating global warming, but that it could also have near-term benefits in the reduction of deaths from respiratory causes."

Other co-authors of the paper are Richard Burnett from Health Canada, the federal health department headquartered in Ottawa; Kaz Ito and George Thurston from the New York University School of Medicine; Daniel Krewski and Dr. Yuanli Shi from the University of Ottawa; and Eugenia Calle and Dr. Michael Thun from the American Cancer Society.

The Health Effects Institute, a non-profit research organization based in Boston, Mass., helped support this research.

An EPA list of where U.S. counties stand in compliance with the current federal ozone standards is available at: http://epa.gov/air/ozonepollution/pdfs/2008_03_design_values_2004_2006.pdf.

WildEarth Guardians Calls on EPA to Slash Smog Pollution in the American West, Safeguard Public Health

Clean Air Act Petition Filed to Fix Flawed Clean Air Regulations in 16 Western States, Tackle Interstate Transport of Air Pollution

DENVER—WildEarth Guardians today petitioned the Administrator of the U.S. Environmental Protection Agency to take aggressive action to safeguard public health and the environment and cut ozone air pollution throughout the American West.

“The American West is facing an unprecedented challenge in addressing the impacts of ozone air pollution,” said Jeremy Nichols, Climate and Energy Program Director for WildEarth Guardians. “For the sake of public health, we’re calling on the Environmental Protection Agency to help us meet this challenge head on.”

Ozone air pollution—the key ingredient of smog—is a poisonous gas that forms when sunlight reacts with pollution from tailpipes, smokestacks, and industrial operations, such as oil and gas drilling. It can scar the lungs of children, trigger asthma attacks, and cause premature death. Federal standards limit ozone concentrations in the air to no more than 0.075 parts per million over an eight-hour period, a very small concentration, reflecting the danger of this pollutant.

The petition comes as mounting evidence shows the American West will be blanketed in smog by 2018. Already, many areas suffering from harmful levels of ozone air pollution. Denver, Salt Lake City, Phoenix, Las Vegas, Los Angeles, and other cities have violated federal clean air standards limiting ozone. However the problem is spreading, even affecting rural communities.

Air quality in northwestern New Mexico and western Wyoming violated ozone limits this year, while hazardous ozone days were reported from remote areas like southern Utah’s Zion National Park and Nevada’s Great Basin National Park.

Recent modeling projects further clean air declines in the American West. By 2018, all or portions of 16 Western States are expected to exceed ozone air pollution limits. The modeling, prepared for the Western Regional Air Partnership, which is associated with the Western Governors’ Association, projects ozone levels will be highest over much of the Southwestern United States and Southern Idaho.

The modeling also shows that ozone is a regional problem in the American West due to interstate transport of pollution. A draft white paper prepared for the Western Regional Air Partnership stated, “[C]ontrary to assessments of the impacts of the new ozone standards based on EPA’s model predictions, WRAP’s modeling efforts highlight the regional nature of the ozone air quality problem throughout the Western US.” The white paper continued, “Within the WRAP region, the ozone air quality problem is clearly a regional issue, as evidenced by regional [ozone] modeling results[.]”

Transport of ozone air pollution is a widely known problem the Eastern United States, but has largely been overlooked in the American West. Mounting evidence shows that slashing smog will require regional solutions that address transport among the Western States.

“With air quality projected to worsen throughout the West, we need regional solutions, not piecemeal plans or fingerpointing,” said Nichols. “The Environmental Protection Agency can provide the leadership and direction needed to put the West on the path toward clean air.”

WildEarth Guardians’ petition today is an urgent call on the U.S. Environmental Protection Agency to take an aggressive, comprehensive, and expeditious approach to tackling ozone air pollution in the American West, as required by the Clean Air Act. The petition calls on the agency to:

• Force 16 Western States to revise their air quality regulations to strengthen ozone air pollution safeguards by 2013. Modeling shows that air quality regulations in the West are failing or will soon exceed limits on ozone air pollution.

• Designate a Western States Interstate Transport Region within 18 months. The designation of an Interstate Transport Region will prioritize the development of regional solutions to tackle ozone air pollution.

• Create a Western States Ozone Interstate Transport Commission. Interstate Transport Commissions are charged with assessing the degree of transport, assessing strategies for combating interstate transport, and recommending strategies for adoption by the EPA.

The petition will also help to focus attention on identifying the key sources of ozone forming pollution and on cutting emissions from sources that contribute most significantly to the regional problem. It is likely that coal-fired power plants, oil and gas drilling operations, cars and trucks, and other industrial sources will be targeted for emission cuts.

“Ultimately, this is about clean energy and smart growth,” said Nichols. “We need to chart a sustainable path forward for the West, that means shifting away from fossil fuels and unchecked growth, and shifting toward renewable energy, efficiency, and smarter planning.”

The petition ultimately requests the Administrator of the Environmental Protection Agency to follow through with basic legal obligations under the Clean Air Act, the nation’s fundamental law protecting public health and welfare from air pollution.

WildEarth Guardians is a nonprofit dedicated to protecting and restoring the American West and is based in Santa Fe, New Mexico with offices in Denver, Phoenix, Bozeman, and Oakland, CA.

See Petition
WildEarth Guardians

New England Experienced More Smog Days During Recent Summer, But Long-Term Trend is Still Toward Cleaner Air

As the 2007 summer ozone season comes to an end, EPA today confirmed that New Englanders experienced a modest increase in the number of poor air quality days this year, compared to 2006. The increase in number of days with reduced air quality is related to hot weather experienced throughout the region during the summer.

Based on preliminary data collected between May and September, there were 26 days when ozone monitors in New England recorded concentrations above levels considered healthy. By contrast, in 2006 there were a total of 16 unhealthy ozone days. Over the longer term, however, the air quality in New England continues to improve.

The number of unhealthy ozone days in each state this summer were as follows: 17 days in Connecticut (compared to 13 in 2006); 20 days in Massachusetts (11 in 2006); 8 days in Rhode Island (3 in 2006); 8 days in Maine (2 in 2006); 6 days in New Hampshire (2 in 2006); and 1 day in Vermont (none in 2006). Ground-level ozone, the main ingredient of smog, is unhealthy when average concentrations exceed 0.08 parts per million over an 8-hour period.

The increase in the number of days with unhealthy air this year was directly related to the increase in the number of hot days this year. Sunlight and high temperatures speed the formation of ground-level ozone smog; many areas of New England had more days exceeding 90 degrees this summer than during last summer. August and September were especially hot, dry and sunny for much of New England.

Although warm temperatures this summer led to an increase in unhealthy days, over the long-term New England has experienced a decreasing number of unhealthy ozone days. Also, peak ozone concentrations have decreased significantly over the last 30 years. In 1983, New England had 90 unhealthy days, compared with 26 this summer. Overall, peak ozone concentrations in New England have decreased by more than 20 percent since 1980.

Another measure of air quality in New England is the geographic extent of the unhealthy air quality. This is determined by counting the number of air quality monitors that recorded exceedances of EPA’s health-protective 8-hour ozone standard. A higher number of monitor exceedances means a more extensive area of unhealthy air quality. When comparing the 2007 ozone season to the 2001 ozone season, a New England summer with temperature data similar to this summer, the total number of monitored exceedances dropped from 349 in 2001 to 175 this past summer. This is an approximately 50 percent decrease in the number of areas exceeding the standard over this six year period.

“When we look back to the air quality conditions a generation ago, we can feel proud of the advances we have made in reducing pollution,” said Robert Varney, regional administrator of EPA’s New England regional office. “The unhealthy days we experienced this summer, however, remind us that our efforts to use cleaner cars and our commitment to reducing industrial emissions and conserving energy in our own daily lives, all measures that lower air pollution, must continue.”

Ground-level ozone (smog) is formed when volatile organic compounds (VOC) and oxides of nitrogen (NOx) chemically react in the presence of sunlight. Cars, trucks and buses give off the majority of the pollution that makes smog. Fossil fuel burning at electric power plants, which run at high capacities on hot days, gives off significant amounts of smog-making pollution. Gas stations, print shops, household products like paints and cleaners, as well as gasoline-powered lawn and garden equipment, also contribute to smog formation.

Exposure to elevated ozone levels can cause serious breathing problems, and aggravate asthma and other pre-existing lung diseases. It can also make people who are vulnerable more susceptible to respiratory infection.

EPA has taken a number of steps to further reduce air pollution. Since model year 2004, new cars, sport utility vehicles, pickup trucks, and minivans are meeting stringent new emission standards. The requirements are being phased in between 2004 and 2009 resulting in vehicles that are 77 to 95 percent cleaner than older models. The program also requires a 90 percent reduction in the sulfur content of gasoline, which is helping reduce emissions from all vehicles new and old. Also, beginning in 2007, EPA’s standards for new diesel engines for trucks and buses will reduce NOx and particulate matter emissions by 90 percent.

In addition, EPA has issued the Clean Air Interstate Rule to help reduce the transport of air pollution from power plants across state boundaries. When fully implemented, this rule will reduce power plant NOx emissions by over 60 percent and sulfur dioxide by over 70 percent from 2003 levels.

Although the 2007 ozone season is ending, pollution from small particles in the air is a year-round concern. The daily air quality index forecast will continue to be available at www.epa.gov/ne/aqi/. New Englanders can also sign up at this address to receive air quality alerts. These alerts are issued by e-mail, whenever necessary, to notify program participants when high concentrations of ground-level ozone or fine particles are predicted to occur, in their area.

Historical charts of unhealthy air days from 1983 through 2007 are available for each state on EPA New England’s web site at: www.epa.gov/ne/airquality/standard.html. A preliminary list of the unhealthy readings recorded this summer by date and monitor location, and corresponding air quality maps for each day, can be found at: www.epa.gov/region1/airquality/o3exceed-07.html.

See the Source:
EPA

Find out:
How to reduce NOx emissions from stationary engines using selective catalytic reduction.

air pollution
NOx emissions

Ozone Controversy – Science vs. EPA vs. Industry

On June 21st, the EPA proposed that it was time to strengthen the nation's air quality standards for ground-level ozone, revising the standards set in 1997. According to the EPA, the new proposal is based on the most recent scientific evidence available about the health effects of ozone, which is the primary component of smog."Advances in science are leading to cleaner skies and healthier lives," said EPA Administrator Stephen L. Johnson. "America's science is progressing and our air quality is improving. By strengthening the ozone standard, EPA is keeping our clean air momentum moving into the future. I have concluded the current standard is insufficient to protect public health."

But environmentalists and scientific experts say the proposed regulations are not enough and fall short of standards recommend by the EPA’s own Clean Air Scientific Advisory Committee (CASAC). According to scientific documents provided to the EPA, lowering emissions standards to 0.064 parts per million rather than EPA’s proposed 0.07-0.075 ppm, would decrease ozone-related deaths by a possible 75 percent. The current regulatory level is .08 ppm.

“The law says use the science, the science says lower the standard to safe levels,” commented Francesco Grifo, director of the Scientific Integrity Program for the Union of Concerned Scientists. “In disregarding its own scientists’ analysis, the EPA is risking the health of millions of Americans.”

Ozone is a health concern for individuals with asthma or other lung diseases, as well as those who spend a lot of time outside, such as children. Ozone exposure can aggravate asthma and increase susceptibility to respiratory infections. Environmentalists believe the new proposed standard is not enough to protect the public’s health, with the higher regulation level being the result of pressure from industrial concerns and the current White House administration.

“The science is clear,” said David H. Ingbar MD, president of the American Thoracic Society, “ozone pollution is causing unnecessary, illnesses and death in America. The proposed EPA standards fall short of providing the protection needed to keep Americans safe from ozone air pollution.” Dr. Ingbar also commented that the proposed standards are “unhealthy for America’s kids, unhealthy for America’s seniors, and unhealthy for America.”

However, the National Center for Policy Analysis’ E-Team, a group of exports who offer analysis based on the concept that science, the environment and the economy should form government policies, issued another perspective to the proposed standards. They stated that reducing smog emissions standards from the current level to the level suggested by the EPA, is virtually impossible, according to Joel Schwarz, an adjunct scholar with the NCPA E-Team. Schwarz continued that even if the proposed reduction were possible, it would do nothing to improve American’s overall health. He continued “These new proposed standards would turn most of the nation into a Clean Air Act ‘non-attainment area.”

Ground-level ozone is not emitted directly into the air, but is created through a reaction of nitrogen oxides (NOx) and volatile organic compound (VOC) emissions in the presence of sunlight. Emissions from industrial facilities, electric utilities, on- and off-road vehicles, gasoline vapors, and chemical solvents are the major man-made sources of NOx and VOCs - ozone precursors.

The EPA says that the United States has made significant progress reducing ground-level ozone in the past quarter century. Since 1980, ozone levels have dropped 21 percent nationwide. Currently 104 US counties are not in compliance with today’s ozone levels. Based on the EPA’s new data and questionable proposed standard, 533 US counties would not be in compliance. Depending on the seriousness of a county’s ozone problems, they would need to comply with the new measures as soon as 2013, with possibly extensions to 2030.

The estimated health benefits of meeting a range of alternative ozone standards based on published scientific studies and the opinion of outside experts will be detailed in a Regulatory Impact Analysis issued by the EPA to be released this summer. Final adoption of the proposed regulations would go into effect by March 12, 2008, after public comment has been heard for 90 days prior to this date.

See the Source:
EPA's proposal to strengthen standards for ground-level ozone
Union of Concerned Scientists
NewsWise
NCPA E-Team

Find out:
How to lower NOx emissions for lean burn engines and gas turbines using selective catalytic reduction.

clean air
NOx emissions

Murky Results for Ethanol Emissions

An environmental engineer from Stanford University using computer modeling software, has compared US air pollution levels in 2020 produced by gasoline fueled-vehicles vs. a fleet that burns an ethanol/gasoline blend of 85/15.

The study indicates that ethanol could potentially add more smog-forming pollutants to the atmosphere than gasoline, by increasing hydrocarbons by 22 percent. This would increase surface ozone, as well as ozone-related deaths. Currently 4,700 people die yearly from respiratory problems related to smog. According to the study, 200 more people would die each year if ethanol use was increased.

In the study published in Environmental Science & Technology, Stanford engineer Mark Jacobson writes: “Due to its ozone effects, future E85 may be a greater overall public health risk than gasoline. It can be concluded with confidence only that E85 is unlikely to improve air quality over future gasoline vehicles."

See the Source:
Scientific American
Environmental Science and Technology
Environmental and Urban Economics

Find out:
How to reduce hydrocarbons using oxidation converters from CleanAIR Systems

air pollution
current issues

EPA Completes Second Step in Ongoing Ground-Level Ozone Air Quality Standards Review

A key document in EPA's review of national air quality standards for ozone will recommend the administrator consider strengthening the current ozone standards to better protect public health. The document, known as the "final staff paper," contains staff recommendations for the administrator to consider in upcoming decisions about revising the agency's ozone standards.

The Clean Air Act requires EPA to periodically review its air quality standards to ensure they continue to protect health and the environment, and to update the standards if necessary. EPA last updated the standards for ozone in 1997.

The final ozone staff paper addresses a primary standard, designed to protect public health; and a secondary standard, set to protect the public welfare, including crop health.

· Primary standard: The final staff paper concludes that the current primary standard is not adequate to protect public health. Staff made this conclusion based on an expanded body of scientific evidence that shows significant ozone health effects occur even in areas with ozone levels below the current standard.

Staff recommends a range of levels for the administrator to consider in setting the ozone standard. That range extends from below 0.080 ppm down to 0.060 ppm. The previous draft of the staff paper identified options that included retaining the current standard of 0.084 ppm, along with a range of alternative levels down to 0.064 (the lowest level analyzed), with a focus on a level of 0.07 ppm.

The final staff paper also recommends specifying the level of the standard to three decimal places. Ozone air quality measurements have advanced sufficiently to now reflect that level of precision.

· Secondary Standard: The final staff paper recommends the administrator set a secondary standard to protect against ozone damage to welfare, including damage to plants. This includes damage to natural vegetation, forests and commercial crops. Staff recommended a standard that is a cumulative, weighted total of daily 12-hour exposures over a three-month period within the growing season. It would give greater weight to exposures at higher ozone concentrations.

Staff also recommended a range for this standard, from 21 parts per million-hours to 7 parts per million-hours.

EPA will make the final ozone staff paper available on the web on Wednesday, Jan. 31, 2007. Also this week, the agency will release technical documents used in developing the staff paper. These documents include a health risk assessment for meeting the current ozone standards along with potential alternative standards, and an assessment of the effects of ozone on vegetation.

The assessments, conclusions and recommendations included in the staff paper are staff judgments. They do not represent agency decisions on the ozone standards. EPA will propose action on the ozone standards by June 20, 2007 and take final action by March 12, 2008.

EPA recently changed the process for reviewing the National Ambient Air Quality Standards to streamline future such reviews to ensure the agency meets its five-year deadlines for reviewing the standards.

Emissions of the pollutants that contribute to ground-level ozone have decreased by nearly 50 percent since 1970, and EPA, and state and local agencies have a number of programs in place to continue this progress.

See the Source:
Final Ozone Staff Paper and Fact Sheet
Technical Support Documents

Find out:
The impact of NOx, a major contributor to ground-level ozone, and how to decrease NOx emissions by up to 95% using CleanAIR's selective catalytic reduction.