[EPA press release - April 30, 1971]

William D. Ruckelshaus, Administrator of the Environmental Protection Agency, today announced final publication of National air quality standards for six common classes of pollutants--sulfur oxides, particulate matter, carbon monoxide, photochemical oxidants, nitrogen oxides and hydrocarbons.

The Clean Air Act required him to set pollution limits at levels that protect the public health and provide an adequate margin of safety. States are required to plan to meet the standards by 1975.

"These are tough standards," Ruckelshaus said. "They are based on investigations conducted at the outer limits of our capability to measure connections between levels of pollution and effects on man. In the case of carbon monoxide, one of the most important automobile pollutants, we have set a standard to protect against effects reported by investigations which prompt arguments even among our own scientists. In the case of photochemical oxidants, also largely contributed to by automobiles, our standards approach levels that occur fairly commonly in nature.

The legislative history of the Clean Air Act makes it plain, he added, "that when we talk about protecting the 'public health' against polluted air, we are talking about protecting those citizens who are particularly sensitive to it--in other words, those citizens already afflicted with cardio-respiratory problems. If we have erred at all in setting these standards, we have erred on the side of public health."

Ruckelshaus emphasized that meeting these standards in the time allowed by the law will have a profound effect on U.S. cities. He said the carbon monoxide problem would be difficult to solve. "Of seven major cities where we have good enough data to make accurate predictions, only one--Cincinnati, Ohio--will come close with the presently contemplated automobile controls in the time allowed. And Cincinnati will not actually reach the standard until 1977," he said.

Ruckelshaus said that in the other six cities--Chicago, Denver, Los Angeles, New York, Philadelphia and Washington--the Federal motor vehicle control program would not bring air pollution down to the standard until sometime in the 1980s.

"If we are to meet the legal deadline for carbon monoxide, then, some cities may have to require drastic changes in their commuting habits," he added.

He said most regions of the country can meet the deadline for sulfur oxides and particulates by switching to low sulfur fuels already available to these regions, and by a much more rigorous application of existing methods for controlling particulate matter. He said some increase in electric bills might result, "but the resources are there."

He said seven metropolitan areas might have serious trouble meeting the sulfur oxides and particulate standards. "The problem is particulates, and the most difficult case from a control standpoint is New York," he said. "We estimate that to bring air pollution levels down to the standard for particulates in New York will require a 300 percent increase in natural gas usage in the city. The only encouraging feature in the prognosis is that curing the particulate problem with natural gas will also take care of the sulfur oxides problem." He forecast somewhat less serious difficulties for Chicago, St. Louis, Baltimore, Hartford, Buffalo, and Philadelphia.

"All in all," he explained, "meeting the particulate standard in the time allowed by the law in these seven cities will require increasing our total national use of natural gas by about 15 percent, and almost half that increase would go to New York City alone. Unless other sources of natural gas are developed, such an increase in the use of this fuel might soon reduce what has been considered a desirable balance between reserves and consumption."

Ruckelshaus said the relationship between levels of hydrocarbons and nitrogen oxides in the air and the production of photochemical oxidants is so complex and at this juncture so little understood, that it is difficult to predict whether or not the Nation will meet the standards for these pollutants in the time allowed by the law. "I am advised that the prospects for achieving significant control of existing stationary sources of the nitrogen oxides themselves in the time allowed by the law are bleak," he said. "However, the picture has its promising aspects. The Federal program for reducing emissions of hydrocarbons and nitrogen oxides from new automobiles, plus the regulations that we will soon issue for controlling nitrogen oxide emissions from new and modified electric power plants, should carry us a considerable distance down the road to an air quality that we and our children can enjoy."