Wednesday May 12 3:12 AM ET

Gas Additive May Not Ease Pollution

By H. JOSEF HEBERT Associated Press Writer

WASHINGTON (AP) - New questions are being raised about the required use of reformulated gasoline in many parts of the country after a group of scientists concluded that the fuel's high oxygen content does little to stem urban smog.

A panel of the National Academy of Sciences said in a report Tuesday that the oxygen-boosting additives used in the gasoline are believed to reduce peak ozone levels ``by only a few percent'' in urban areas with serious smog problems.

Ground-level ozone, or smog, has declined more than 10 percent since 1986 in urban centers and continues to decline. But the 11-member panel said ``it is not certain that any part of these trends can be significantly attributed to the use of reformulated gasoline.''

The study, which had been requested by the Environmental Protection Agency, said reformulated gasoline does have a number of characteristics, other than higher oxygen levels, that do lower pollution from automobiles and light trucks. The group made no recommendation on whether to continue the program.

Reformulated gasoline has been required by the EPA since 1995 in areas that have severe smog, including in all or parts of 17 states from New England to Texas and Wisconsin, as well as California.

But the most widely used oxygenate, MTBE, has been the focus of controversy as critics argue that it has its own environmental and health risks. Maine this month stopped requiring the special gasoline and has asked to get out of the federal program. California reversed course and said it would ban the additive beginning in 2002 because MTBE has been found in lakes and streams.

The addition of MTBE or ethanol to gasoline, in itself, ``is likely to have little air quality impact in terms of ozone reduction,'' the study by the Academy's National Research Council said. It said reductions in volatile organic compounds and carbon monoxide from cars ``appears to be quite small'' and that the additive may lead to more nitrogen oxide being released.

Ozone, or smog, is the result of sunlight interacting with a number of pollutants including hydrocarbons and nitrogen oxides from tailpipe or evaporation from motor vehicles. At high levels, especially in summer, it is a severe irritant that can damage lung tissues and aggravate respiratory problems.

While the EPA said it supports the technical findings of the report, it said the study should not dissuade the continued use of the reformulated blends of gasoline. The agency in a statement that the report confirms that the gasoline additive reduces toxic emissions and that it has the potential of cutting smog-causing chemicals from cars as much as 20 percent.

``Cleaner gasoline are an important tool for achieving cleaner air and protecting public health and we expect that some form of cleaner gasoline will always be in demand,'' EPA spokesman David Cohen said.

William Chameides, the science panel's chairman and a professor at the Georgia Institute of Technology, also said the report should not be interpreted to suggest reformulated gasoline be abandoned.

``Not at all,'' Chameides said in a telephone interview. ``We are simply looking at the impact.'' He said that overall reformulated gasoline may be environmentally beneficial, but that ``it is not possible to attribute a significant portion of past reductions in smog to the use of these gasoline additives.''

The Oxygenated Fuels Association, a trade group, said the report ``is completely at odds with a host of real world findings ... which show that (reformulated gasoline) with oxygenates is working effectively in helping clean up our air.''

The EPA directed in 1993 that reformulated gasoline, containing an oxygen additive, be used in nine urban areas with the most severe smog problems. Other states were allowed to begin requiring the fuel is some counties if they wanted to.

Currently the cleaner gasoline is used in all or part of 16 states: California, Connecticut, Delaware, Illinois, Indiana, Kentucky, Massachusetts, Maryland, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Texas, Virginia and Wisconsin.

While Maine is still formally part of the program, awaiting EPA approval to leave it, the special gasoline stopped being sold in the state this month.