Docket No. A-95-54, 61 Fed. Reg. 65,637 (December 13, 1996)

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(Lack of scientific evidence)

(Death due to cost)

(Current trends in air quality make the imposition of a new air quality standard unnecessary)

(EPA Has Failed To Comply With The Unfunded Mandates Reform Act)


(Electricity Daily article on these comments)


The Competitive Enterprise Institute (CEI) is a non-profit public interest group committed to advancing the principles of free markets and limited government. CEI has a long-standing interest in issues involving matters of public health and safety, with a particular interest in bringing to light the potentially deleterious consequences of regulations, which are often neglected by federal agencies in their attempts to adopt a regulatory agenda.

As the following comments will elucidate, there is no sound scientific basis for the proposed change in the National Ambient Air Quality Standards for Particulate Matter. Moreover, the EPA has failed to adequately consider likely adverse impacts of imposing a new standard. For these reasons, CEI believes that the proposed rule should either be substantially revised or withdrawn.


The EPA's Clean Air Scientific Advisory Committee concluded that there may be a reasonable basis upon which to establish a National Ambient Air Quality Standard for PM2.5 to accompany the existing standard for PM10. However, "there was no consensus on the level, averaging time, or form" of such a standard among members of the CASAC, due to "many unanswered questions and uncertainties associated with establishing causality of the association between PM2.5 and mortality." Some members of the CASAC opposed setting any PM2.5 standard at this time whatsoever.

The diversity of views among the CASAC members is evidence of the great scientific uncertainty surrounding the impact of ambient concentrations of particulate matter on human health. Given this uncertainty, it is premature for the EPA to impose as stringent a new PM2.5 NAAQS as has been proposed. While the EPA Administrator is seeking . . . to prevent lower pollution levels that she finds may pose an unacceptable risk of harm," ambient levels of particulate matter are declining. This trend is expected to continue, suggesting that there is no need for the Administrator to impose a new standard at this time.

All regulations impose costs, economic and otherwise. In this instance, the EPA has failed to consider whether the proposed standard may actually increase mortality due to reductions in disposable income that compliance efforts may produce. Moreover, there are serious questions as to whether the EPA has fully complied with the Unfunded Mandates Reform Act in proposing this rule.

The proposed standard cannot be supported by the available scientific evidence.

The proposed standard for particulate matter is largely based upon a handful of epidemiological studies that purport to show an association between levels of urban air pollution and mortality. In particular, the proposed standard is based upon two studies that allegedly document a weak association between current levels of particulate matter and mortality. Indeed, such weak associations are rarely the basis for federal rulemaking, nor should they be.

The risk factors these studies report -- 1.17 and 1.26 -- are well below those that are generally accepted to demonstrate a potential cause-and-effect link between an environmental factor and mortality. Most scientific professionals are highly skeptical of studies that purport to demonstrate a cause-and-effect link based upon such a weak association. According to Dr. Lynn Rosenberg of the Boston University School of Medicine, "A relative risk of 1.3 (that is, a 30 percent increase in risk) is in epidemiological terms virtually indistinguishable from a risk of 1.0 (that is, no increase in risk)." This is also the position of the National Cancer Institute: "In epidemiological research, relative risks of less than 2.0 are considered small and are usually difficult to interpret. Such increases may be due to chance, statistical bias, or the effects of confounding factors that are sometimes not evident."

Not only do the studies in question report an exceedingly weak association, they also suffer from methodological flaws that undermine the reliability of their conclusions. These flaws include a reliance upon self-reported data and a failure to measure actual pollution levels to which subjects were exposed. The former is a particular problem because of the potential for smoker misclassification, which could easily account for the small reported increase in mortality.

In addition, the epidemiological studies failed to account for numerous confounding variables that have been associated with mortality in the scientific literature, including marital status, socializing, fitness, and nutrition.

Adjusting for confounding variables is always important when dealing with small relative risks, as a small error or oversight in adjusting for such variables can easily produce or mask small associations. This is particularly true in the current instance as studies of the aforementioned confounding variables have found significantly stronger associations with mortality rates than have the particulate matter studies upon which the EPA bases the proposed standard.

Independent reviews of the available data on the potential relationship between ambient levels of particulate matter and human health dispute the have come to conclusions other than those adopted by the EPA. For instance, one recent review of the costs and benefits of EPA air quality regulations concluded with respect to particulates that:

"the most likely hypothesis that would realistically account for all of the available pertinent evidence is that the principal cause of the excess mortality and morbidity detected in the studies is exposure to airborne biological and chemical allergens emitted indoors, rather than exposure to airborne PM or any other substances emitted from anthropogeic (human) sources into the outdoor air."

In other words, the purported association between particulate levels and mortality observed in the epidemiological studies may be caused by other variables that have not been considered in the EPA's analysis. This suggests that the purported health benefits of establishing a stringent new NAAQS for particulate matter could be significantly less than estimated in the EPA's proposal.

The scientific uncertainty upon which the standard is based is not seriously questioned by the EPA. Indeed, the rulemaking proposal acknowledges that "the relevant toxicological and controlled human studies published to date have not identified an accepted mechanism(s) that would explain how such relatively low concentrations of ambient PM might cause the health effects reported in the economic literature."

Due to the questionable scientific basis, it would be irresponsible for the EPA to impose stringent new standards for particulate matter on the American people.

The EPA has failed to consider the ADVERSE potential consequences of the proposed standard, such as an increase in premature mortalities caused by the Economic cost of COMPLIANCE.

The enactment of regulatory proposals and standards always carries with it the risk of unintended consequences. Changes in resource and energy use produced by regulatory demands can often reduce the intended benefits of the rule.

In the area of public health protection there is always a risk that regulations designed to increase protection of human health may have the opposite effect. In particular, regulations that diminish economic growth and disposable income can have negative consequences for public health. There is a strong correlation between incomes and health status. Across and within populations, as incomes rise, health improves and as income falls, mortality and morbidity increase. In other words, wealthier is healthier and poorer is sicker; "The data on life expectancy and economic level for more recent times all point in the same direction: the lower the income, the higher the death rate at an earlier age."

The wealth-health connection is supported by a significant body of academic research. "The implication of these findings for regulatory analysis is that when national income is spent complying with regulations, there are negative health effects as well as positive health benefits of the regulation." As Judge Stephen Williams of the D.C. Circuit Court of Appeals noted, "[H]igher income can secure better health, and there is no basis for a causal assumption that more stringent regulation will always save lives. . . . Incremental safety regulation reduces incomes and thus may exact a cost in human lives."

Regulations that divert scarce resources away from life-saving and/or growth enhancing investments can result in an increase in mortality. It has been conservatively estimated that "each $7.5 million of costs generated by regulation may, under certain assumptions, induce one fatality." Other studies suggest that an economic loss to the economy of approximately $5 million to $10 million will result in an additional premature fatality.

This same point has been made by Supreme Court Justice Stephen Breyer:

At all times regulation imposes costs that mean less real income to individuals for alternative expenditure. That deprivation of real income itself has adverse health effects, in the form of poorer diet, more heart attacks, more suicides. To obtain an order of magnitude, a sample of academic studies suggests, as a conservative estimate, that every $7.25 million spent on a cleanup regulation will, under certain assumptions, induce one additional fatality through this "income effect"; that a 1 percent increase in unemployment, sustained over five years, means 19,000 more heart attacks and 1,100 more suicides over that time; and that risk varies inversely with family income such that "a 1 percent change in income reduces mortality by about 0.05 percent on average." (citations omitted)

Based upon the EPA's current, albeit incomplete and specualtive, analysis, the proposed standard would result in a net decrease in mortality. Yet this conclusion is far from certain for several reasons. First, as discussed above, the scientific basis for the proposed rule is exceedingly weak, and therefore the presumed benefits of the proposed rule may be ephemeral. Second, there are reasons to question the methodology that the EPA has used to quantify the costs and benefits of air quality regulations. Such concerns were not adequately addressed during the rulemaking process because the Office of Information and Regulatory Affairs had only a few weeks to review the proposed standards, rather than the 90 days called for in Executive Order No. 12866. Third, and perhaps most importantly, the EPA has only estimated the costs and benefits for partial attainment of the new standard. There is no guarantee that the cost-benefit ratio will be so favorable for full implementation. Indeed, as most pollution control efforts experience diminishing marginal returns, the ratio is likely to worsen.

Moreover, there may well be regional disparities in compliance costs and the benefits of pollution reduction. Should a disproportionate regulatory burden be placed upon select communities, one would expect disproportionate concentration of premature mortalities caused by the economic burden of complying with the new standard. The EPA should consider the possibility before enacting the proposed standard.

Potential unintended consequences, including an increase in mortality caused by excessive regulatory expenditures, should be considered by the EPA before imposing a stringent new air quality standard that will impose significant costs in many communities. Indeed, it would be a violation of the Agency's implicit obligation to safeguard human health were such potential impacts not to be considered.

Current trends in air quality make the imposition of a new air quality standard unnecessary.

It is well documented that air quality trends are improving in the vast majority of urban areas throughout the nation. This is as true for particulate matter as it is for other pollutants. In 1996, the EPA reported that "the national average of annual mean PM-10 concentrations decreased 22 percent while PM-10 emissions decreased 17 percent." It is likely that smaller particulates, such as those that would be covered by the proposed PM 2.5 standard, declined as well, and will continue to decline as particulate matter control measures continue to implemented in accordance with existing regulatory and statutory requirements.

Continued improvement in air quality reduces the purported need for imposing a new air quality standard to protect against potential risks to human health. Indeed, because the health benefits of a new standard are speculative and the costs are real, current trends in air quality suggest that the EPA is justified in waiting to impose a new standard until such time when there is sufficient scientific justification for a new standard.

The rulemaking proposal acknowledges that "The Act does not require the Administrator to establish a primary NAAQS at a zero-risk level, but rather at a level that reduces risk sufficiently so as to protect health with an adequate margin of safety." Given current downward trends in urban PM concentrations, withdrawing the current proposal until such time when there is more definitive scientific data on the purported connection between particulate matter and human health would not violate the Administrator's statutory obligations, particularly if ongoing research into the potential effects of particulate matter on human health is maintained.

In the Proposed Change in the National Ambient Air Quality Standards for Particulate Matter, The EPA Has Failed To Comply With The Unfunded Mandates Reform Act

The Unfunded Mandates Reform Act (UMRA) places specific requirements on the Congress and federal agencies in the consideration of laws and rules that impose costs on non-federal governments and the private sector. Subchapter II of the UMRA requires agencies proposing such rules to conduct certain assessments as to their impact, to consult with affected non-federal officials, and to choose the most cost-effective or least burdensome alternative that achieves the objectives of the rule. The proposed rule, if enacted, will result in the imposition of significant costs on state and local governments and private entities, and is precisely the type of federal action for the which the UMRA was created. However, the EPA has failed to conduct the required analyses and is in violation of the UMRA.

The EPA's claim that the proposed rule is exempt from the UMRA is unavailing. First, the agency states that the proposed rule, in and of itself, will not impose costs in excess of the threshold of $100 million because it is merely a standard-setting rule, and that a separate round of subsequent implementing rules will actually impose the costs. The UMRA applies to "any general notice of proposed rulemaking that is likely to result in promulgation of any rule that includes any Federal mandate that may result in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $100,000,000 or more..." (emphasis added). Thus, the EPA's strained attempt to segregate the standard setting phase from the inevitable subsequent implementing phase does not avoid application of the UMRA, as the proposed rule is highly likely to result in the promulgation of these future rules that will indeed impose burdens on non-federal governments and the private sector well in excess of $100 million. The statutory language clearly anticipates and eliminates the possibility of avoiding the UMRA by simply splitting the process of imposing unfunded mandates into several rulemaking steps, as the EPA is attempting to do here.

The EPA also claims that the UMRA does not apply to this proposed rule on the grounds that its requirements are prefaced by the phrase "[u]nless otherwise prohibited by law," and thus the rules promulgated pursuant to Title I of the CAA are exempted because the primary standards are to be based on public health, and not on costs. However, the EPA misinterprets the UMRA. The "unless otherwise prohibited by law" language applies only to statutes that exempt implementing agencies from conducting the analyses required under UMRA. Most of the requirements under UMRA do not conflict with those in the CAA. The agency can, and by law must, comply with UMRA, and doing so will not in any way interfere with its statutory mandate under the CAA.


Imposing stringent new regulatory burdens without a solid scientific foundation is not sound public policy. The Administrator is under legal obligation to impose a new NAAQS for particulate matter, particularly when the questionable nature of the underlying scientific data makes the benefits of such a standard highly uncertain, and a wealth of data connecting income and mortality demonstrates that imposing severe regulatory burdens on the economy can literally have lethal consequences.

Urban air quality in the United States is improving, and should continue to improve for some time irrespective of whether the EPA imposes a new standard for particulate matter. Simply put, there is no sound scientific basis for the EPA's proposed PM 2.5 NAAQS, and ample reason in fact and law not to impose such a standard. For these reasons, CEI believes that the proposed rule should either be substantially revised or withdrawn.

Respectfully Submitted,

Jonathan H. Adler

Director of Environmental Studies

Ben Lieberman

Environmental Research Associate