We have come a long way since the Clean Air Act Amendments of 1990. Since that last reauthorization effort, we have successfully and economically made major reductions in emissions of air pollutants and tremendously expanded our understanding of the causes and effects of environmental problems such as acid deposition, ozone pollution, decreased visibility, and eutrophication of coastal waters. We can be proud of these accomplishments, but we still have a long way to go. And first on our priority list should be action on the evidence that nitrogen oxides (NOx), which we largely ignored nine years ago, are significant contributors to air quality deficiencies.
The 1990 Amendments did not go far enough to prevent continued human health and ecosystem damage from NOx. In particular, we now know that ozone pollution, caused in large part by NOx emissions, can have a terrible effect on human respiratory functions. A 1996 study of ozone pollution by the Harvard University School of Public Health established a strong link between ground level ozone pollution and 30,000-50,000 emergency room visits
during the high ozone seasons of 1993 and 1994. Nearly 9,000 of those visits occurred in New York City alone, during the summer of 1994. And of course the ecosystem effects of NOx--coastal eutrophcation, acid deposition and nitrogen saturation--are well-documented. Clearly, any serious effort to address this problem must address NOx emissions. Fortunately, we have identified an unusual opportunity to make enormous NOx reductions at a minimal cost--through a simple reduction in gasoline sulfur content.
The Clean Gasoline Act of 1999, and the EPA rule, address "mobile sources" (mainly cars and trucks) of NOx and other tailpipe emissions. Mobile sources account for 50% of US NOx emissions. By establishing a national, year-round cap on the sulfur content of gasoline sold in the United States, the EPA proposal would dramatically and immediately reduce NOx emiqqions from the very largest single source.
And this is how:
The presence of sulfur in gasoline increases vehicle emissions by "poisoning" the catalytic converter used to capture tailpipe emissions. In essence, particles of sulfur coat the surface of the catalytic converter and render it partially ineffective. In the 1970s, we removed lead from gasoline to make possible the introduction of catalytic converters. Now we have learned that sulfur is a catalyst poison in much the same way. All vehicles in the nation with catalytic converters -- virtually all vehicles -- produce higher levels of NOx because of the high levels of sulfur in the gasoline they burn. By reducing the amount of sulfur in gasoline, we will allow our national fleet to immediately realize reductions in tailpipe emissions.
The cost of gasoline would rise under this proposal -- by less than a nickel a gallon at the retail level. For a car driven 15,000 miles per year that achieves IS miles per gallon, the
cost of the proposal would be less than $50 annually. Keep in mind, however, that gasoline prices, adjusted for inflation, are cheaper now than they have been at any time since 1950, the beginning point of our analysis. And the benefits to human health and the environment of reducing gasoline sulfur far outweigh this modest cost.
A recent study by the State and Territorial Air Pollution Program Administrators and the Association of Local Air Pollution Control Officials (STAPPA-ALAPCO) found that reducing gasoline sulfur levels to 40 parts per million, the California standard, will bring an air quality benefit equivalent to removing nearly 54 million vehicles from our national fleet. New York City alone would have a benefit equal to removing 3 million vehicles from its streets. We must not pass up the opportunity to make such large gains in emissions reductions for such a minor cost.