EPA Seeks Tougher SO₂ Rule

EPA proposed new air quality regulations last week for sulfur dioxide emissions, which come primarily from coal-burning power plants and industrial facilities. The proposal would set a national one-hour standard for concentrations of SO₂ in the atmosphere between 50 and 100 ppb. The hourly standard would replace existing 1971 regulations that limit sulfur concentrations to 140 ppb measured over 24 hours and an annual average concentration of 30 ppb. EPA says the new standard will "better protect public health by reducing people's exposure to high short-term concentrations of SO₂," which can aggravate asthma and cause respiratory difficulties. Compliance is expected to cost industries between $1.8 billion and $6.8 billion, the agency estimates. Sen. Thomas R. Carper (D-Del.), chairman of the Senate Clean Air Subcommittee, endorsed the agency's action. "Current federal standards simply fail to protect public health," Carper said in a statement.