Strict Smog Standards Proposed by EPA

The United States Environmental Protection Agency proposed on Thursday the strictest health standards to date for smog. Smog, also known as ground-level ozone, is linked to a number of serious health problems, ranging from aggravation of asthma to increased risk of premature death in people with heart or lung disease. Ozone can even harm healthy people who work and play outdoors. The agency is proposing to replace the standards set by the previous administration, which many believe were not protective enough of human health.

“EPA is stepping up to protect Americans from one of the most persistent and widespread pollutants we face. Smog in the air we breathe poses a very serious health threat, especially to children and individuals suffering from asthma and lung disease. It dirties our air, clouds our cities, and drives up our health care costs across the country,” said EPA Administrator Lisa P. Jackson. “Using the best science to strengthen these standards is a long overdue action that will help millions of Americans breathe easier and live healthier.”

The agency is proposing to set the “primary” standard, which protects public health, at a level between 0.060 and 0.070 parts per million (ppm) measured over eight hours. Children are at the greatest risk from ozone, because their lungs are still developing, they are most likely to be active outdoors, and they are more likely than adults to have asthma. Adults with asthma or other lung diseases, and older adults are also sensitive to ozone.

EPA is also proposing to set a separate “secondary” standard to protect the environment, especially plants and trees. This seasonal standard is designed to protect plants and trees from damage occurring from repeated ozone exposure, which can reduce tree growth, damage leaves, and increase susceptibility to disease.

In September 2009 Administrator Jackson announced that EPA would reconsider the existing ozone standards, set at 0.075 ppm in March 2008. As part of its reconsideration, EPA conducted a review of the science that guided the 2008 decision, including more than 1,700 scientific studies and public comments from the 2008 rulemaking process. EPA also reviewed the findings of the independent Clean Air Scientific Advisory Committee, which recommended standards in the ranges proposed today.

Depending on the level of the final standard, the proposal would yield health benefits between $13 billion and $100 billion. This proposal would help reduce premature deaths, aggravated asthma, bronchitis cases, hospital and emergency room visits and days when people miss work or school because of ozone-related symptoms. Estimated costs of implementing this proposal range from $19 billion to $90 billion.

Ground-level ozone forms when emissions from industrial facilities, power plants, landfills and motor vehicles react in the sun.

More information: http://www.epa.gov/groundlevelozone

Austin May Become Non-attainment Region

Tuesday, August 18th, the Mayor of Austin, air quality officials and environmental groups urged the city's residents to decrease energy use and motor vehicle trips in an effort to control pollution. The city has two months to clean up its act before the EPA designates Austin as an "ozone non-attainment region".

City officials are worried that the EPA designation will have a negative impact on economic growth, darkening Austin's green image.

Ozone levels can be lowered by decreasing energy production and usage, as well as restricting the burning of fossil fuels (fewer road trips). When ozone levels are high it can cause inflammation of the lungs and respiratory infections.

Ozone Can Impair Lung Function

Ozone exposure, even at levels deemed safe by current clean air standards, can have a significant and negative effect on lung function, according to researchers at the University of California Davis.

“The National Ambient Air Quality Standard (NAAQS) for ozone was recently revised to set lower limits for ozone concentrations. Our research indicates that the threshold for decrements in ozone-induced lung function in healthy young subjects is below this standard,” said Edward Schelegle, Ph.D., of the University of California Davis. “Specifically, we found that 6.6 hours exposure to mean ozone concentrations as low as 70 parts per billion have a significant negative effect on lung function, even though the current NAAQS standards allow ozone concentrations to be up to 75 parts per billion (ppb) over an eight-hour period.”

The results we published in the August 1 issue of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

To test whether mean ozone concentrations above and below the new standard induce lung function decrements and to further study the time-course of these decrements, Dr. Schelegle and colleagues recruited 31 healthy nonsmoking individuals to participate in 6.6-hour sessions during which they were exposed to ozone at 60, 70, 80 or 87 ppb or filtered air while undergoing six 50-minute bouts of moderate exercise followed by 10-minute breaks. A 35-minute lunch break separated the third and fourth bouts of exercise.

Lung function for each subject was assessed before, during and after exposure, and each individual answered a questionnaire evaluating their subjective symptoms. Of the four levels of ozone concentration tested, Dr. Schelegle and colleagues found significant decrements in both lung function and subjective respiratory symptoms at 70 ppb and above, beginning at 5.6 hours after exposure.

“These data tells us that even at levels currently below the air quality standard, healthy people may experience decreased lung function after just a few hours of moderate to light exercise such as bicycling or walking,” said Dr. Schelegle. “While these changes were fully reversible within several hours, these findings highlight the need to study susceptible individuals, such as asthmatics, at similar ozone concentrations and durations of exposure. These studies are needed to better understand the acute rise in hospitalizations that often occur in conjunction with high-ozone periods.”

The study also supports the previously reported smooth dose-response curve associated with ozone. That is, the higher the level of ozone, the greater the decrease in lung function. However, the healthy subjects in the study showed a marked individual variability in their responses to ozone, with a few exhibiting strong sensitivity to ozone concentrations. What causes some individuals to respond strongly while others do not is still unknown.

“Schelegle and colleagues do not, nor did they seek to explain the determinants of susceptibility in young, healthy adults,” noted James S. Brown, of the U.S. Environmental Protection Agency, in an accompanying editorial. “Only with continued research efforts will we be able to better characterize the susceptibility in some healthy individuals, to the effects of short-term ozone exposures.”

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California Almanac of Emissions and Air Quality

Air quality Almanac includes state air quality trends San Joaquin Valley and South Coast Air basins show lower PM levels and fewer ozone days

The Air Resources Board released its annual California Almanac of Emissions and Air Quality this month that shows dramatic improvement in air quality in two of the historically troubled areas - Southern California and the Central Valley - despite increased trucking, port activities and population growth.

The almanac indicates pollutants have dropped significantly over the last 20 years in both San Joaquin Valley and the South Coast Air basins. Ozone levels have decreased approximately 10 percent in the San Joaquin Valley and 35 percent in the South Coast Air basins since 1990. Fine particulate matter in the South Coast region has decreased nearly 35 percent and the San Joaquin Valley 20 percent for the period of 1999 to 2007 namely due to regulations aimed at reducing ozone and coarse particulate matter.

Data from the statewide 2009 almanac also shows that over the last 20 years:
• A dramatic decrease of 53 percent in hydrocarbons and 35
percent in NOx emissions that contribute to the formation of ozone and PM;
• The number of unhealthy days with high concentrations of ozone
has decreased an average of 35 percent;
• Exposure to ozone in major urban areas has dropped
approximately 80 percent;
• A number of areas in the state that previously violated the
federal 1-hour ozone standard now meet the standard; and
• All areas of California now meet state and national standards
for nitrogen oxides, carbon monoxide and sulfur dioxide.

"These good statistics covering the past 20 years show a lot of progress simultaneous with growth in population and economy but, there is still more to be done," said ARB Chairman, Mary D.

Nichols. "We will continue to employ innovative approaches to keep California on the right track so we protect public health which will result in a healthier workforce and fewer hospital visits for families."

These air pollution reductions are a result of regulations adopted by ARB and the 35 local air quality districts over the last 40 years. Recent efforts such as the adoption of tougher particulate matter and NOx regulations from big-rig trucks and buses, and equipment enhancements at California service stations are expected to help the state meet more stringent air quality standards.

ARB’s California Almanac of Emissions and Air Quality is produced annually and contains information about historical, current and forecasted emissions trends as well as historic air quality data. The data is collected from over 200 monitoring stations that are operated and maintained in partnership with local air districts.

Each year, more than 10 million air quality measurements are collected from all the stations and are stored in a comprehensive air quality database maintained by the ARB. To ensure the integrity of the data, ARB routinely audits and reviews the monitoring instruments and data.
To view a downloadable version of the almanac, go to:
http://www.arb.ca.gov/aqd/almanac/almanac09/almanac09.htm