環保署是在聽取「清淨空氣科學諮詢委員會」(Clean Air Scientific Advisory
環保署這次的行動起源於四年前的一場訴訟，當時密蘇里州瓦頓夫婦（Leslie and Jack
Co.）所營運、美國當時唯一的鉛冶煉廠。當時，鎮上已有工作場地和街道受鉛污染，許多兒童出現鉛中毒徵狀。 瓦頓訴訟案指控政府並未按照清淨空氣法（Clean Air
Association of Clear Aire Agencies）執行長貝克（Bill
Resources Defence Council）資深科學家所羅門博士（Gina
Today, for the first time in 30 years, the U.S. EPA strengthened the nation's air quality standards for lead, improving public health protection, especially for children, who are particularly vulnerable to lead poisoning.
Lead is a pollutant that can cause organ, brain and nerve damage, lower intelligence, suppress the immune system, cause high blood pressure and increase heart disease. The major sources of lead emissions have been motor vehicles and lead smelters, waste incinerators, utilities, and lead-acid battery manufacturers.
The new standards reduce the allowable lead level 10 times to 0.15 micrograms of lead per cubic meter (ug/m3) of air. The previous standards, set in 1978, were 1.5 micrograms of lead per cubic meter of air.
EPA strengthened the standards after a review of the science on lead, advice from the Clean Air Scientific Advisory Committee, and consideration of public comments.
EPA's action sets two standards: a primary standard at 0.15 ug/m3 to protect health and a secondary standard at the same level to protect the public welfare, including the environment.
The EPA action results from a lawsuit filed four years ago by Leslie and Jack Warden, Missouri residents who sought to get the federal government to consider tougher standards for lead in the air.
The Wardens used to live in Herculaneum, which is near the nation's only primary lead smelter, run by the Doe Run Co. Many Herculaneum children have suffered from lead poisoning, and lead has contaminated yards and streets of the town.
The Wardens' lawsuit alleged, and a federal judge agreed, that the Clean Air Act requires the air quality standard for lead to be reviewed every five years, and the government had not done so. The EPA first set the standard in 1978 and it has not changed since.
The new air lead standard is only as strong as its enforcement, and concerns were expressed today that the EPA's monitoring capacity is not up to the job.
Bill Becker, executive director of the National Association of Clean Air Agencies, said, "We commend EPA for setting the primary and secondary lead standards at 0.15 micrograms per cubic meter, which is within the range recommended by the agency's science advisors on the Clean Air Scientific Advisory Committee. However, we are disappointed that the rule has obstructed the public's ability to know whether the air they breathe is safe."
The EPA acknowledged today that the existing monitoring network for lead is not sufficient to determine whether many areas of the country would meet the revised standards.
In the new regulation, the EPA changed the calculation method for the averaging time to use a "rolling" three month period with a maximum not-to-be-exceeded form, evaluated over a three-year period. This replaces the current approach of using calendar quarters.
But environmentalists warn that represents a loophole in the new standards through which lead can enter the environment.
"I am disappointed that EPA will allow averaging of lead exposures over a three-month period," Solomon said. "That means that large but brief 'spikes' of lead emissions from smelters and other polluters could contaminate the soil of playgrounds and backyards even in some areas that are in attainment of the new standard."