WASHINGTON, DC, November 17, 2009 (ENS) – For the first time in nearly 40 years, the U.S. Environmental Protection Agency is proposing to strengthen the nation’s sulfur dioxide air quality standard to protect public health.
Power plants and other industrial facilities emit sulfur dioxide, SO2, directly into the air where it forms fine particles and acid rain. Exposure to SO2 can aggravate asthma, cause respiratory difficulties, and result in emergency room visits and hospitalization. People with asthma, children, and the elderly are especially vulnerable to exposure to this gas.
“Short-term exposures to peak SO2 levels can have significant health effects – especially for children and the elderly – and leave our families and taxpayers saddled with high health care costs,” said EPA Administrator Lisa Jackson. “We’re strengthening clean air standards, stepping up monitoring and reporting in communities most in need, and providing the American people with protections they rightly deserve.”
EPA is taking public comment on a proposal to establish a new national one-hour SO2 standard, between 50 and 100 parts per billion may be present in the air during in any one hour period.
This standard is designed to protect against short-term exposures ranging from five minutes to 24 hours.
The existing standards are 140 parts per billion measured over 24 hours, and 30 ppb measured over an entire year.
Because the revised standards would be more protective, EPA is proposing to revoke the current 24-hour and annual SO2 health standards.
The EPA estimates that the revised standards would yield health benefits valued between $16 billion and $100 billion. Those benefits would include reduced hospital admissions, emergency room visits, work days lost, cases of aggravated asthma and chronic bronchitis.
The Miami Fort coal-burning power plant on the Ohio River 15 miles west of Cincinnati. (Photo credit unknown)
Sulfur dioxide is a gas composed of sulfur and oxygen that forms when sulfur-containing fuel such as coal, oil, or diesel is burned. Sulfur dioxide converts in the atmosphere to sulfates, a prime component of fine particle pollution in the eastern United States. Spikes in SO2 occur in areas near coal-fired power plants.
The EPA also is proposing changes to monitoring and reporting requirements for sulfur dioxide. Monitors would be placed in areas with high SO2 emission levels as well as in urban areas.
The proposal also would change the Air Quality Index to reflect the revised SO2 standards. This change would improve states’ ability to alert the public when short-term SO2 levels may affect their health, Jackson said.
The proposal addresses only the SO2 primary standards, which are designed to protect public health. Jackson says EPA will address the secondary standard – designed to protect the public welfare, including the environment – as part of a separate proposal in 2011.
EPA first set National Ambient Air Quality Standards for sulfur dioxide in 1971, establishing both a primary standard to protect health and a secondary standard to protect the public welfare. Annual average SO2 concentrations have decreased by more than 71 percent since 1980.
The public comment period will be open for 60 days after the proposal is published in the Federal Register. The agency will hold a public hearing on January 5, 2010 in Atlanta. EPA must issue final standards by June 2, 2010.
The American Lung Association called the action “long overdue” and urged EPA to set a standard at a level that truly protects public health.
“The American Lung Association recommends EPA adopt a standard of 50 parts per billion – the most protective level under consideration,” the group said in a statement.
In Texas, Neil Carman, speaking for the Lone Star Chapter of the Sierra Club, applauded the EPA proposal.
“Sierra Club fully supports today’s EPA proposal to require a significantly improved national protective standard on sulfur dioxide, one of the worst coal plant pollutants for human respiratory systems,” said Carman, who directs the Clean Air Program for the Lone Star Chapter.
“Sierra Club has strived to reduce sulfur dioxide from coal plants and this ruling will require that coal plants add the necessary new scrubbers,” he said. “Texas lignite is a wetter and dirtier fuel, so the proposed new EPA sulfur dioxide standard will also definitely reduce the use of lignite.”
The 17 coal plants in Texas emit 492,456 tons of SO2 annually and cause 1,105 hospital admissions, 1,791 heart attacks, and 1,160 deaths every year in Texas, according to 2004 report by the Sierra Club.
“The need to protect the public health definitely underscores the fact that coal plants are not a good way to meet our energy needs,” Carman said. “It’s vitally important that we’re improving our protective standards and coal companies have to deal with the serious costs to society of burning coal for electricity.”