emissions historically have been regulated under the Clean
Air Act because of health concerns. Sulfur dioxide interacts
in the atmosphere to form sulfate aerosol particles which
can be inhaled. In the eastern U. S. sulfate aerosols
constitute about 25 percent of inhalable particles.
These particles account for about half of visibility reduction
in these same areas.
Sulfur is a contaminate in oil
which makes its way into gasoline for motor vehicles.
The federal EPA wants sulfur levels of gasoline sold
in the United States reduced substantially. So,
in December 1999, President Clinton announced a mandated
schedule for a major reduction of gasoline sulfur content.
California has switched to low-sulfur gasoline and the European
Union, Japan, and Canada have decided to follow suit. Calfornia
regulators believe that the move to low-sulfur gasoline
in 1996 was the most important step toward improving air
quality since the 1975 introduction of the catalytic converter.
Haze over national
parks has been a decades-old problem. Sulfur dioxide is
a major culprit. The Clinton administration proposed a rule
to eliminate 90% to 95% of sulfur emissions from 26 industrial
sources, particularly 600 old (1962-1977) coal-fired power
plant boilers. With public opinion polls plummeting due
to hard-line environmental stances, the Bush administration
in 2001 supported the changes.
Last updated on Tuesday, July 24, 2001