Agriculture and EPA's New Air Quality Standards
for Ozone and Particulates

The Ozone and Particulate Issues

Scientific Underpinnings
Implementation Issues
Regulatory Impacts Specific to Agriculture

The Ozone and Particulate Issues

The issues raised by revision of the ozone and particulate standards can be grouped in at least three categories: the adequacy of the science underpinning the standards; questions regarding implementation; and regulatory impacts, including the costs and benefits of the proposals. Only the last of these has any unique agricultural component; nevertheless, because of EPA's mandate under the Clean Air Act, the costs and benefits to agriculture (or any other sector of the economy) did not play a central role in shaping the proposals.

Scientific Underpinnings. Questions concerning the scientific underpinnings of EPA's proposal have assumed a predominant role in the debate. EPA estimates that fine particles cause 40,000 deaths per year, and that the proposed standard will reduce this mortality by 15,000 lives winually. The ozone standards' projected effects are less dramatic: EPA estimates that implementation of the ozone proposal would reduce the risk of significant decrease in children's lung flinctions by 1.5 rnillion to 2 million incidences per year, reduce the risk of moderate to severe respiratory symptoms in children by 200,000 to 400,000 incidences per year, and prevent 1,600 hospital admissions and 5,000 emergency room visits annually. The standards will have many additional effects, both positive and negative, but under the Clean Air Act and its interpretation by the courts, EPA is prohibited from considering effects other than public health in the setting of air quality standards.

Thus, much of the debate has focused on the quality of the scientific data EPA used to reach its conclusions. Representative Larry Combest, chair of the House Agriculture Committee's Subcommittee on Forestry, Resource Conservation, and Research, which held a hearing on the standards April 23, 1997, reflected the views of many in Congress and in the agricultural community in stating:

The science employed in developing this nile is not up to par, and I'm concerned that fiLmiers could bear the brunt of a bad policy based on equally bad Science.... According to much of the testimony we heard today, it appears the EPA's proposed standards do not reflect the science that is available.8

While witnesses at this hearing (including scientific witnesses) offered information to support this conclusion, proponents of the standards have disggreed in other forums. Dr. Morton Lippmann, of New York University's Nelson Institute of Environmental Medicine, a member of every scientific panel that has conducted EPA reviews of the ozone and particulate NAAQS since 1980, concludes that there has never been a proposed standard better supported by the science. He and others note that the particulate panel of the Clean Air Scientific Advisory Committee (CASAC) agreed by a vote of 19-2 that fine particles should be regulated, and that a separate CASAC panel that reviewed the ozone documents reached consensus that "although our understanding of the health effects of ozone is far from complete, the document [EPA's staff paper outlining potential primary standards] provides an adequate scientific basis for making regulatory decisions concerning a primary ozone standard."9

There is, however, a consensus among both proponents and opponents that there is a need for additional research, which might lead EPA to flirther revision of the standards, especially regarding fine particles. There is virtually no monitoring data for PM2.5. Little is known about the biological mechanisms that lead from inhalation of PM2.5 to disease or death. And there is controversy concerning whether PM2.5 (a broad category that includes many different types of particles) or some specific particle type within the broad category is the appropriate pollutant to regulate.

Ultimately, the issue of the adequacy of the science base for EPA's proposed standards could affect agriculture in two ways. First, there is the question of whether EPA has the scientific data to assess correctly the effects of the pollutants. If the standards are too stringent, unnecessary costs of control will be incurred, possibly affecting agriculture adversely. Conversely, if the standards are insufficiently stringent, unnecessary harm from air pollution may result, which for ozone could include adverse effects on agricultural productivity.

Second, there is the question of whether flirther research would implicate agriculture as a source of air pollutants subject to regulation - for example, as discussed below, whether agricultural sources of ammonia contribute to adverse effects attributed to PM2.5 and might be subject to regulation.

The requirement of the Clean Air Act that EPA regularly review the NAAQS makes it clear that EPA must make a decision on the science base available. What is at issue is the level at which the standards should be set given the available science.

Implementation Issues. A number of issues have been raised concerning the consistency of the proposed standards with current provisions of the Clean Air Act and the pace at which air quality improvements would occur under the proposed standards.

The Clean Air Act, as written, specifically references the existing 1-hour, 0.12 ppm ozone standard (Section 181) and the PM10 standard (Section 188) in categorizing nonattainment areas; areas with ozone readings of 0.121 to 0.138 are defined as Marginal and given a 3 -year deadline to reach attainment; 0.138 to 0.160 as Moderate, with a 6-year deadline; 0.160 to 0.180 as Serious, with a 9-year deadline; etc. Section 182 spells out requirements for each of the five ozone noncompliance categories, and Section 185 contains specific enforcement requirements for the two worst categories (Severe and Extreme) if they fail to attain the standard within the deadlines. Similarly, Section 189 spells out requirements for the PM10 noncompliance areas.

When the ozone standard changed from 0.12 ppm to 0.08 ppm, the statutory definition of the 5 nonattainment categories became an anomaly, requiring measured progress toward a standard that no longer exists -- even though virtually all parties concede that the ozone control measures required under the law are the same types of controls one would use to meet the new standard.

Since EPA is proposing to retain the existing PM10 standard, the question of references in the CAA specially to PM10 as the PM standard poses less of a problem. Nevertheless, the measures outlined in Sections 188-190 do not address compliance with the PM2.5 standard.

EPA has set forth an implementation plan for dealing with the transition to new ozone and PM standards, but the implementation plan itself raises questions. The issue is not whether EPA can implement new ozone and PM standards: the Act provides EPA general authorities to implement air quality standards. The issue is whether EPA can disregard specific statutory requirements relating to the existing standards, as implied by the implementation plan.

A related set of questions concerns what all acknowledge is likely to be a lengthy process for implementing the new standards. As noted earlier, after promulgation of the standards, it is 5-8 years before any regulatory decisions affecting industry or other economic sectors are required to be implemented by the states based on the revised ozone standard, and lO-12 years before any regulations are likely to be promulgated implementing the PM2,5 standard. Lawsuits challenging the standards may cause ftirther delay.

With regard to fine particulates, the lengthy schedule for implementation leads some to conclude that conducting fbrther research to obtain greater certainty before regulating would have little impact on public health, particularly as several existing clean air programs, such as Title IV (concerning acid precipitation), will reduce PM2.5 in the interim. The same set of facts prompts others to suggest that the standard needed to be promulgated as soon as possible to shorten what is certain to be a lengthy implementation process. There is general agreement that EPA will still have time to revisit the PM2.5 standard in 5 years, as required by the Act, before any measures are taken to control emissions.

Proponents of acting now argue that the standards can be revised based on additional research, but that without a commitment to move forward with regulations, there will be little impetus to conduct the additional research. Proponents of delay, on the other hand, argue that huge expenditures of limited resources will be set in motion by the setting of a standard, and that there should be greater certainty about the scientific underpinnings before those resources are committed.10

Regulatory Impacts Specific to Agriculture. Even if there were no controversies over the science or implementation issues, there would still be questions about how these proposals would impact the economics of agriculture and other economic sectors. Farmers are less able than many other businesses to pass increased costs along to those who purchase their products because prices are set in commodity markets in which individual producers have negligible influence. That inability, combined with a concern about the potential consequences of these changes, has galvanized the farm community. Critics of the proposals raise the specter of especially severe effects on small farmers with limited incomes. Affected farmers of any size might have any number of controls placed on their actions, according to these critics, from mandating no till days to requiring that the ground be moistened before it is worked. These concerns in some part reflect a situation of uncertainty, as EPA has not stated what guidance it might develop affecting agricultural activities for states to meet the new standards.

Most of the concerns about costs expressed by agricultural stakeholders reflect potential costs, based on assumptions about the implementation of the proposed standards. The uncertainties in the science underlying the standards, as previously noted, and the uncertainties about how the standards would be implemented, since this is a fliture phase in the process, give considerable range to such assumptions about potential costs. However, it is possible to identify factors concerning each proposed standard that place certain boundaries on potential costs and indicate with some specificity which decisions are key to those costs. These boundaries indicate that, to the extent that agricultural stakeholders are concerned about the costs of EPA's proposals, their focus should be on the PM2.5 standard, but that key decisions that could affect those costs will not be made for 10 or more years.

Ozone Issues. Ozone received relatively little attention at any of the Agriculture committee or subconnnittee hearings. Agriculture recognizes that it is adversely affected by ozone. Testimony from the National Audubon Society estimated that ozone can be responsible for up to a 10% loss in crop production. Because the proposed standard would lower ozone concentrations in agricultural areas of the South, Midwest, and Northeast, EPA has estimated a $1 billion annual savings for agriculture based on increased crop yields from this proposal. Agricultural interests challenge the magnitude of these projected savings.

Part of this challenge is based on a concern that ozone measurements are generally taken in urban areas, and agricultural representatives believe that ozone levels are much lower in rural areas. If they are lower, the crop losses and the crop benefits are both likely to be less than the estimates above. If ozone is not as significant a problem in rural areas, these critics argue that agriculture should not be required to address it, as the health benefits would be limited. Some of the characteristics of ozone pollution in rural areas were identified in a recent policy forum.11 The authors concluded that with new regulations in place, large areas of the eastern United States would be in non-attainment and require regional control strategies, with potentially significant costs. The role agriculture might play is unclear.

Proponents of EPA's proposal respond in two ways. First, unlike other polk[tants for which there are National Ambient Air Quality Standards, ozone is not emitted directly into the atmosphere, but forms downwind when sunlight and heat catalyze a chemical reaction between nitrogen oxides NOx) and volatile organic compounds (VOCs). Once formed, ozone can be transported long distances from urban to rural areas. Thus, rural areas are as likely as urban ones to experience high ozone levels, provided that they are downwind of the sources of ozone precursors.12

Second, proponents agree with agricultural interests that farmers do little to generate the nitrogen oxides and volatile organic compounds that cause ozone to form in the atmosphere. As a result, they argue, agriculture is unlikely to be a target of regulation under the ozone proposal. In short, they contend agriculture should benefit from these changes.

The actual measures to be taken to reach attainment would be determined by states through what are called State Implementation Plans. All states model air quality based on current emissions and ambient air quality data, and implement emission control measures sufficient for the models to demonstrate attainment. As EPA notes,

There are thousands of sources of these gases [ozone precursors]. Some of the more common sources are gasoline vapors, chemical solvents, combustion products of various fliels, and consumer products. These products can be frequently found in large industrial fhcilities, gas stations, and small businesses such as bakeries and auto body repair shops. 13

By sector, the major sources of NOx, and VOCs include transportation, electric utilities, petroleum refining and marketing, chemical manufacturing, paints, and architectural coatings. The impacts on agriculture from regulating these sources are most likely to be indirect, primarily the result of engine modifications that could be required of the manufacturers of farm equipment or fuel modifications that might increase the cost of gasoline or diesel fuel.

Endnotes

8 House Committee on Agriculture News Release, April 23, 1997

9 Closure letter from Dr. George T. Wolff, Chairman, Clean Air Scientific Advisory Committee, to EPA Administrator Carol Browner, November 30, 1995, p.1.

10 Bills seeking delay of the standards include HR. 1984 (K'ink) and S. 1084 (Inhofe). Senator Inhote's amendment (S.Amdt. 1687), although substantially different from S. 1084, is considered a substitute for the bill. In discussing the amendment during Senate debate, March 4, Senator Inhofb announced that if the amendment were enacted, he did not intend to bring up any other legislation or amendments affecting the NAAQS.

11 Chamcidcs, W.L., et. Al., Ozonc Pollution in the Rural United States and the New NAAQS. Science. Vol.276, May 9, 1997. P.916.

12 Maine is a good example. With very few sources of pollution, five counties in Maine several with as few as 30,000 - 40,000 people) exceeded the ozone standard in 1995, primarily because of pollutants transported downwind from other states.

13 U.S. EPA, Office of Air Quality Planning and Standards, National Air Quality and Emissions Trends Report, 1995, Report No. EPA 454/R-96-005, Research Triangle Park, NC, October 1996, p.21.