Printed for the use of the Committee on Public Works

U.S. GOVERNMENT PRINTING OFFICE

COMMITTEE ON PUBLIC WORKS

JENNINGS RANDOLPH, West Virginia, Chairman

STEPHEN M. YOUNG, Ohio
EDMUND S. MUSKIE, Maine

ERNEST GRUENING, Alaska

B. EVERETT JORDAN, North Carolina
DANIEL K, INOUYE, Hawaii
BIRCH BAYH, Indiana

JOSEPH M. MONTOYA, New Mexico
JOSEPH D. TYDINGS, Maryland
WILLIAM B. SPONG, JR., Virginia

JOHN SHERMAN COOPER, Kentucky
HIRAM L. FONG, Hawaii

J. CALEB BOGGS, Delaware
GEORGE MURPHY, California
LEN B. JORDAN, Idaho

HOWARD H. BAKER, JR., Tennessee

RICHARD B. ROYCE, Chief Clerk and Staff Director
M. BARRY MEYER, Counsel

BAILEY GUARD, Assistant Chief Clerk (Minority)

JOSEPH F. VAN VLADRICKEN, LEON G. BILLINGS, J. B. HUYETT, Jr.,
and RICHARD D. GRUNDY, Professional Staff Members

(II)

LETTER OF TRANSMITTAL

U.S. SENATE,

Hon. JENNINGS RANDOLPH,

Washington, D.C., July 23, 1968.

Chairman, Committee on Public Works,

U.S. Senate, Washington, D.C.

DEAR MR. CHAIRMAN: I hereby transmit a staff report on Air Quality Criteria, prepared for the use of the Subcommittee on Air and Water Pollution in connection with its review of the air pollution control program.

The document is, insofar as possible, an objective analysis of the factors relevant to the development of such criteria in line with the policies established by the Air Quality Act of 1967 (Public Law 90148). It represents an exhaustive and impressive amount of research by the staff of the subcommittee, particularly Mr. Richard D. Grundy, which should make a valuable contribution to the work of our committee.

Sincerely,

EDMUND S. MUSKIE,

Chairman, Subcommittee on Air and Water Pollution.

(III)

PREFACE

Air pollution levels cannot be allowed to continue to rise indefinitely. The health implications of such lack of control and abatement measures are dramatic and manifold. The question that must be resolved is: when and to what degree should control be exercised?

There is ample quantitative evidence of acute air pollution effects on public health and welfare during air pollution episodes in which persons with chronic bronchitis, lung cancer, and other respiratory and cardiopulmonary diseases have suffered aggravated distress or death. There is evidence that air pollution decreases the performance of otherwise healthy individuals. On the other hand, there is limited knowledge on the effects of long-term exposure to relatively low concentrations of contaminants over periods of 10, 20, or 30 years.

Still less attention has been paid to the effects of contaminants which are accumulated in human organs. It has been shown that there are a number of contaminants in the environment that can be accumulated in the human body and have potential adverse health effects if absorbed or accumulated in sufficient quantities. These effects are characterized by changes in the biochemical system and various body functions.

Limited knowledge exists concerning human toxicology for many of the contaminants found in the atmosphere under conditions of chronic exposure. Under these conditions the critical effects appear to be carcinogenic, mutagenic, as well as other systemic effects. It is quite clear that protection of public health requires quantitative answers regarding the effects of such chronic exposures. These answers are best derived from prospective studies. Without an answer to the above question there is no assurance that the control and abatement established for protection against acute conditions (for example, air pollution episodes) will provide adequate protection of public health and welfare against chronic long-term exposures at less than acute levels.

In the interim public health standards must be established on the basis of the best available evidence while continually expanding the knowledge base. It must be remembered that cause-effect relations involving health are studied by empirical tools and empirical methods. There are no sharp lines defining cause and effect.

The suggestion that "threshold effects" exist is deceiving. Many effects are not observed because study techniques are either insensitive or the effects unsuspected. As knowledge improves on the cause-effect relation, new and more refined techniques will be required to better delineate dose-response relationships. The techniques used 10 years ago are not good enough today and there is no reason to assume that analytical methods and techniques used today will suffice tomorrow. Both new and more positive research methods combined with new and constantly broadening scientific and social concepts are needed.