Statistical Smog Clouds Air Debate

The U.S. Environmental Protection Agency’s deadline for public comment on its proposed new air quality standards ended March 12. The agency wants to tighten the standard for ground-level ozone (smog) and create a new standard for particulate matter (soot) with a diameter of 2.5 microns or less (hundreds of such particles could fit into the period at the end of this sentence). Although there has been no shortage of public comment during the past three months, it is not clear how all these viewpoints will be (or should be) taken into account.

To facilitate the public comment process, EPA set up a telephone hot line and electronic mail addresses. The American Lung Association, environmental groups, and organizations like Parents of Asthmatic Children have large bases of grassroots support that can be easily mobilized to make a quick phone call to EPA. This type of support is making a large impact on EPA’s tally sheet; so far, the agency’s hot line has received six comments in support of new air quality standards for every one comment against them.

But in what sense are these “quick and easy” comments meaningful? The public comment phase has turned out to be more of a popularity contest than an opportunity for concerned and informed parties to offer intelligent observations.

Moreover, the average citizen has been misled by the packaging and PR spin that EPA has applied to the standard-setting process. The agency is on a court-ordered schedule to finalize a particulate matter standard by July 19. Although it is not under such a deadline for the ozone standard, it has chosen to propose new standards for the two air pollutants simultaneously. The agency defends its decision by claiming that the two pollutants have many contributing air emissions in common, thus warranting an integrated approach.

Another explanation is that linking the two proposals allows EPA to mask the shortcomings of each with the strong points of the other.

Ozone medical research is extensive and the pollutant’s physical effects relatively well documented. Its health effects are generally mild and reversible, and the public health benefit that would result from the proposed standard is correspondingly small. For example, asthmatic hospital admissions in the New York City area would likely be cut by only about six tenths of one percent as a result of reaching the proposed standard relative to attaining the current standard.

But the costs of the ozone standard would be very high. EPA’s own Regulatory Impact Analysis (which grossly understates costs by not including many cities with the worst smog problems, i.e. New York and Los Angeles) indicates that the costs of partially attaining the proposed standards likely would exceed the health benefits projected.

In contrast to ozone, the scientific evidence on fine particulate matter is far from compelling. EPA officials make statements about the hundreds of peer reviewed scientific research studies that have gone into their review, but these statements are misleading. In fact, EPA has documented far fewer studies to support the fine particle standard. Only ten studies show health effects from the pollutant that the agency has targeted - particles which measure 2.5 microns or less. Indeed, only two studies show an association between fine particles and mortality.

Nonetheless, the agency maintains that it has conclusive evidence that fine particulate matter causes mortality. EPA has based its estimate of preventing 20,000 premature deaths each year on just these two studies. These tenuous estimates of lives saved, in turn, drive the agency’s high benefit estimates for the fine particle standard. At $5,000,000 per life saved (EPA’s assumed value, independent of length of the prolongation of life or the age or health of the person whose life is extended), the benefits easily swamp what would otherwise be considered significant costs - $120 billion in benefits versus $6 billion to $7 billion in costs.

The ozone and particulate matter proposals packaged together are not unlike two drunks leaning on each other as they stagger down the sidewalk. The scientific evidence of ozone-induced health effects is reasonably well developed, but the proposed ozone standard flunks a cost-benefit test. For particulate matter, the science is in its infancy and is still rife with uncertainties, but the figure for hypothetical lives saved drives high benefit estimates.

The two proposals, which do not stand on their own, together form an attractive bundle. The “popular vote” public comment process can be easily manipulated by promoting this regulatory package and calling on concerned individuals to rally to the cause.

Is this any way to craft clean air policy?

The American people rightly expect to be protected from levels of air pollution that could significantly impair public health. However, they do not expect to pay higher prices for products, face fewer employment opportunities, or change their lifestyles as a result of environmental standards that are unnecessarily costly or scientifically flawed.

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