State and Community Reactions to the Federal Air Pollution Program

The Federal Air Pollution Program is growing rapidly. Its activities are affecting state and local programs both directly and indirectly. Some of these activities are discussed and suggestions are made for developing closer cooperation in the areas of program grants, motor vehicle emission control, Federal abatement procedures, and technical assistance.     

Federal Air Pollution Prevention and Abatement Responsibilities and Operations

The direct federal role in air pollution control was expanded and intensified by the 89th Congress to include authority for: (1) abatement of international pollution; (2) promulgation and enforcement of regulations regarding emissions from new motor vehicles and engines; and (8) the conduct cf conferences and formulation of advisory recommendations concerning potential air pollution of substantial significance. Experiences under interstate abatement authorities of the Clean Air Act and plans for future activities under the new authorities are discussed.     

Modeling of Personal Exposures to Ambient Air Toxics in Camden,New Jersey: An Evaluation Study

Abstract

This study presents the Individual Based Exposure Modeling (IBEM) application of MENTOR (Modeling ENvironment for TOtal Risk studies) in a hot spot area, where there are concentrated local sources on the scale of tens to hundreds of meters, and an urban reference area in Camden, NJ, to characterize the ambient concentrations and personal exposures to benzene and toluene from local ambient sources. The emission-based ambient concentrations in the two neighborhoods were first estimated through atmospheric dispersion modeling. Subsequently, the calculated and measured ambient concentrations of benzene and toluene were separately combined with the time-activity diaries completed by the subjects as inputs to MENTOR/IBEM for estimating personal exposures resulting from ambient sources. The modeling results were then compared with the actual personal measurements collected from over 100 individuals in the field study to identify the gaps in modeling personal exposures in a hot spot. The modeled ambient concentrations of benzene and toluene were generally in agreement with the neighborhood measurements within a factor of 2, but were underestimated at the high-end percentiles. The major local contributors to the benzene ambient levels are from mobile sources, whereas mobile and stationary (point and area) sources contribute to the toluene ambient levels in the study area. This finding can be used as guidance for developing better air toxic emission inventories for characterizing, through modeling, the ambient concentrations of air toxics in the study area. The estimated percentage contributions of personal exposures from ambient sources were generally higher in the hot spot area than the urban reference area in Camden, NJ, for benzene and toluene. This finding demonstrates the hot spot characteristics of stronger local ambient source impacts on personal exposures. Non-ambient sources were also found as significant contributors to personal exposures to benzene and toluene for the population studied.     

Multi-adsorbent Preconcentration and Gas Chromatographic Analysis of Air Toxics with an Automated Collection/Analytical System

Section 507 of the 1990 Clean Air Act Amendments (CAAA) requires states to develop a small business stationary source and environmental compliance assistance program to aid small businesses impacted by applicable air quality regulations. In general, the program consists of three main components: (1) a small business assistance program (SBAP) for providing compliance and technical assistance to small businesses; (2) an ombudsman for providing direct oversight to the SBAP; and (3) a compliance advisory panel consisting of members from both the public and private sector responsible for determining the overall effectiveness of the SBAP. The key component of the program for assisting small businesses is the SBAP. Providing the necessary assistance to small businesses regarding such issues as permit applicability, rights under the CAAA and emission control options will require the SBAP to develop both proactive and reactive components. The proactive component involves providing outreach services in the form of collecting and disseminating compliance and technical information to small businesses. The reactive component includes the establishment of an information clearinghouse for handling the many inquiries from members of the small business community who have never been subject to air pollution control regulations. States without the available resources to fully implement an SBAP may need to rely on contractor assistance. This paper briefly describes the establishment of the program, provides an overview of each of the program components, discusses many of the ways in which states may implement both the proactive and reactive components of the SBAP, and lists the types of contractors most suitable for SBAP assistance.     

Air Quality Modeling and Decisions for Ozone Reduction Strategies

Abstract

Despite the widespread application of photochemical air quality models (AQMs) in U.S. state implementation planning (SIP) for attainment of the ambient ozone standard, documentation for the reliability of projections has remained highly subjective. An “idealized” evaluation framework is proposed that provides a means for assessing reliability. Applied to 18 cases of regulatory modeling in the early 1990s in North America, a comparative review of these applications is reported. The intercomparisons suggest that more than two thirds of these AQM applications suffered from having inadequate air quality and meteorological databases. Emissions representations often were unreliable; uncertainties were too high. More than two thirds of the performance evaluation efforts were judged to be substandard compared with idealized goals. Meteorological conditions chosen according regulatory guidelines were limited to one or two cases and tended to be similar, thus limiting the extent to which public policy makers could be confident that the emission controls adopted would yield attainment for a broad range of adverse atmospheric conditions. More than half of the studies reviewed did not give sufficient attention to addressing the potential for compensating errors. Corroborative analyses were conducted in only one of the 18 studies reviewed. Insufficient attention was given to the estimation of model and/or input database errors, uncertainties, or variability in all of the cases examined. However, recent SIP and policy‐related regional modeling provides evidence of substantial improvements in the underlying science and available modeling systems used for regulatory decision making. Nevertheless, the availability of suitable databases to support increasingly sophisticated modeling continues to be a concern for many locations. Thus, AQM results may still be subject to significant uncertainties. The evaluative process used here provides a framework for modelers and public policy makers to assess the adequacy of contemporary and future modeling work.     

Air Quality Management in Los Angeles: Perspectives on Past and Future Emission Control Strategies

The 1988 Air Quality Management Plan was approved by the Board of the California South Coast Air Quality Management District in March 1989. The District comprises the counties of Los Angeles, Orange, and Riverside, and the non-desert portion of San Bernardino county. Emissions reductions in the past have lead to significant improvement in air quality despite large increases in growth. However, the District, largely because of continuous growth, currently violates the air quality standards for ozone, carbon monoxide, nitrogen dioxide, and respirable particulate matter (PM₁₀). Based upon the AQMP, reduction of approximately 80 percent in emissions of oxides of nitrogen and volatile organic compounds is required to bring the District into compliance with all air quality standards in the next twenty years.

Achieving compliance will necessitate the use of advanced technologies, as well as some changes in lifestyle and management practices. Advanced technologies, including the use of electric vehicles powered by batteries or fuel cells, the use of cleaner burning fuels and advanced combustion modifications, and treatment of surface coatings and solvents are included in the AQMP. The Technology Advancement Office in the District was created to work with industry, universities, research institutes, and other local, state and federal agencies to identify, evaluate, and promote low emitting fuels and technologies. In addition to electricity, fuels burning cleaner than conventional gasoline or diesel are being tested to obtain emissions and durability data so that rational choices can be made for the future. Compressed natural gas, methanol and liquefied petroleum gas are considered to be cleaner burning fuels for current applications. Ethanol, butane, and various oxygenated blends are being evaluated, and the broader application of solar energy and hydrogen are being investigated.

The impact of various cleaner burning fuels on air quality is being addressed. To date, methanol is the only fuel for which results are available. These results indicate that methanol use in vehicles—with control of formaldehyde emissions below 15 mg/mile for light-duty vehicles—can provide air quality benefits for all criteria pollutants and certain air toxics. These benefits are greater for M₁₀₀ than M₈₅.

Several District advanced technology programs are described, including a reduction in emissions from paints and coatings, and the demonstration of electric vehicles.     

State and Local Manpower Resources and Requirements for Air Pollution Control

A recent survey discloses that the total number of professional and technical personnel currently employed in state and local air pollution control agencies is small relative to the total employment of scientists, engineers, and technicians in state and local government generally. The data also indicate that very few positions in control agencies require specialized formal training in air pollution control prior to employment. In general, the future demand for qualified personnel to staff state and local programs depends fundamentally upon our national air quality objectives and the abatement strategy for achieving these objectives. Not until air quality objectives have been made operational and a comprehensive control strategy has been adopted will it be possible to make meaningful forecasts of future state and local manpower requirements. State and local control agencies could probably meet their present requirements by attracting qualified scientists, engineers, and technicians from other fields, if they had salary structures which were competitive with those of industry and the federal government.     

Mortality and Air Pollution: Revisited

This paper represents an exploratory effort to estimate a physical nonlinear function between excess mortality rates and the SO₂ concentration with both considerations over econometric problems such as multicollinearity and heteroscedasticity (the residuals of regression analysis), and the threshold levels. Through a recursive and stepwise adjustment procedure, the average physical mortality function was generalized with much more complete specifications. That is, the generalized average mortality model includes not only the demographic, socioeconomic, and climatological determinants but also air pollution variable. The average pollution damage function developed in this study with observations from relevant SMSA’s which have pollution concentrations exceeding the threshold level represents an important departure from the prior studies in which sample observations were selected regardless of the SO₂ concentration level.     

Clean Air Corridors: A Geographic and

Meteorological factors, pollutant emissions, and geographic regions related to transport of low optical extinction coefficient air to Grand Canyon National Park were examined. Back trajectories were generated by two models, the Atmospheric Transport and Dispersion Model (ATAD) and an approach using the Nested Grid Model output for a Lagrangian particle transport model (NGM/ CAPITA). Meteorological information along the trajectories was analyzed for its relationship to visibility at the Grand Canyon. Case studies considered days with anomalously clean air from the southwest and dirty air from the northwest. Clean air was most frequently from the north and northwest, rarely from the south. Low emissions, high ventilation and washout by precipitation was associated with clean air. All clean days with transport from the Los Angeles area had upper-level low pressure over the region with high ventilation and usually abundant precipitation. The dirtiest days with transport from the northwest were affected by forest fires.     

Air pollution and mortality: A history

Mortality is the most important health effect of ambient air pollution and has been studied the longest. The earliest evidence relates to fog episodes but with the development of more precise methods of investigation it is still possible to discern short-term temporal associations with daily mortality at the historically low levels of air pollution that now exist in most developed countries. Another early observation was that mortality was higher in more polluted areas. This has been confirmed by modern cohort studies that account for other potential explanations for such associations. There does not appear to be a threshold of effect within the ambient range of concentrations. Advances in the understanding of air pollution and mortality have been driven by the combined development of methods and biomedical concepts. The most influential methodological developments have been in time-series techniques and the establishment of large cohort studies, both of which are underpinned by advances in data processing and statistical analysis. On the biomedical side two important developments can be identified. One has been the application of the concept of multifactorial disease causation to explaining how air pollution may affect mortality at low levels and why thresholds are not obvious at the population level. The other has been an increasing understanding of how air pollution may plausibly have pathophysiological effects that are remote from the lung interface with ambient air. Together, these advances have had a profound influence on policies to protect public health. Throughout the history of air pollution epidemiology, mortality studies have been central and this will continue because of the widespread availability of mortality data on a large population scale and the weight that mortality carries in estimating impacts for policy development.     

Air Pollution and Mortality: Issues and Uncertainties

Abstract

Results from 31 epidemiology studies linking air pollution with premature mortality are compared and synthesized. Consistent positive associations between mortality and various measures of air pollution have been shown within each of two fundamentally different types of regression studies and in many variations within these basic types; this is extremely unlikely to have occurred by chance. In this paper, the measure of risk used is the elasticity, which is a dimensionless regression coefficient defined as the percentage change in the dependent variable associated with a 1% change in an independent variable, evaluated at the means. This metric has the advantage of independence from measurement units and averaging times, and is thus suitable for comparisons within and between studies involving different pollutants. Two basic types of studies are considered: time-series studies involving daily perturbations, and cross-sectional studies involving longer-term spatial gradients. The latter include prospective studies of differences in individual survival rates in different locations and studies of the differences in annual mortality rates for various communities.

For a given data set, time-series regression results will vary according to the seasonal adjustment method used, the covariates included, and the lag structure assumed. The results from both types of cross-sectional regressions are highly dependent on the methods used to control for socioeconomic and personal lifestyle factors and on data quality. Amajor issue for all of these studies is that of partitioning the response among collinear pollution and weather variables. Previous studies showed that the variable with the least exposure measurement error may be favored in multiple regressions; assigning precise numerical results to a single pollutant is not possible under these circumstances. We found that the mean overall elasticity as obtained from timeseries studies for mortality with respect to various air pollutants entered jointly was about 0.048, with a range from 0.01 to 0.12. This implies that about 5% of daily mortality is associated with air pollution, on average. The corresponding values from population-based cross-sectional studies were similar in magnitude, but the results from the three recent prospective studies varied from zero to about five times as much. Long-term responses in excess of short-term responses might be interpreted as showing the existence of chronic effects, but the uncertainties inherent in both types of studies make such an interpretation problematic.     

Clean Air and Energy: Reform of the PSD Provisions of the Clean Air Act

Air pollution regulation in the United States has come under repeated attack over the years for a number of reasons. Early in the past decade, prevention of significant deterioration (PSD) legislation, which protects currently clean areas, came into conflict with domestic energy production goals. This paper presents an applied analysis of present and alternative regulations for achievement of PSD air quality goals. A model of the Four Corners region of the Southwest is developed, and several policy alternatives tested in terms of economic efficiency and ability to achieve air quality goals. Alternatives examined include emission fees, marketable emission permits, and technological standards.     

Air Quality: Status,Management and Direction

The Tenth Government Affairs Seminar conducted by the Air Pollution Control Association was held in Washington, D.C. on March 17–18, 1982. The APCA Government Affairs Committee of which John S. Lagarias is Chairman, sponsored this meeting. Dr. Jerry Pell was General Chairman of the Seminar Steering Committee which included in its membership: Gordon M. Rapier, Vice-chairman, William K. Bonta, Facilities Chairman, Barbara Bankoff, David Benforado, D. Kent Berry, Samuel Booras, William Chapman, Stanley Coloff, Philip T. Cummings, Roy S. Denham, Gerald P. Dodson, Daniel Dreyfus, Raymond W. Durante, Victor S. Engleman, Richard Grundy, W. G. Hamlin, Glenn Hanson, G. Steve Hart, Terrence Li Puma, Michael Lukey, John E. Maroney, William Megonnell, Curtis A. Moore, Russell Mosher, Joseph Mullan, Sidney R. Orem, Dennis G. Seipp, Martin L. Smith, Roger Strelow, Michael Tinkleman, Neal Troy.

This meeting served as a forum for discussion of the issues of: the Clean Air Act amendments, regulatory reform, international perspectives on acid rain, and new directions pursued by the U.S. Environmental Protection Agency.

Representative Henry A. Waxman, Chairman, Subcomittee on Health and the Environment, Committee on Energy and Commerce, U.S. House of Representatives, was the keynote speaker. The Honorable C. Boyden Gray, Counsel to the Vice President of the United States was the luncheon speaker on Wednesday. Daniel J. Goodwin, President, State and Territorial Air Pollution Program Administrators, was the luncheon speaker on Thursday.

Session 1. entitled “The Clean Air Act: Legislative Status,” was moderated by G. Steve Hart, President of APCA. Session 2. “Regulatory Reform,” was chaired by Richard N. Holwill, Vice President for Government Information, The Heritage Foundation. The Honorable A. Alan Hill, and Gordon Snow, from the President’s Council on Environmental Quality were co-moderators for Session 3. which was entitled, “Acid Rain: International Perspectives.” Session 4. “Critical Issues,” was moderated by Walter C. Barber, Jr., Director, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency.

Condensed versions of the remarks of the participants are presented here. A more extensive summary of the meeting which includes floor discussion is available in the Proceedings of the Tenth APCA Government Seminar which can be obtained from APCA headquarters.     

Air Pollution and Morbidity: SO2 Damages

The role of SO₂ and COH (coefficient of haze) as causative factors in hospital emergency room admissions for respiratory and cardiac disease is analyzed using data from Chicago's Cook County Hospital. Some of the findings are that, while COH appears not to affect morbidity, SO₂ does, with most important impacts being felt by those with cardiac disease, females, and the youngest and oldest age groups. It is concluded that marginal morbidity damages, about which little had been known, are not high relative to other damage categories. These damages are estimated to be on the order of 10 cents per microgram per cubic meter per person per year.