Thank you Mr. Chairman and members of the Environment and Public Works’ Subcommittee for the opportunity to speak with you today about implementing the National Ambient Air Quality Standards (NAAQS) for fine particles and ground-level ozone. I serve as the Director of the Division of Air and Waste Management for the Delaware Department of Natural Resources and Environmental Control. I previously served in a similar position in the Missouri Department of Natural Resources, and previously in the Environmental Management office of the U.S. Department of Energy and for a private engineering consulting firm. With me today is Ali Mirzakhalili, who is the Administrator of the Air Quality Management Section in our Division. Together we have more than 40 years of professional experience in air pollution control and engineering.

At the outset, let me compliment Senators Voinovich and Carper for their leadership on reducing diesel emissions. The Diesel Emissions Reduction Act (DERA), enacted as part of the Energy Bill, can be a vital piece of the puzzle we are gathered here today to solve. We agree with the recent letter by the National Governors’ Association, the National Conference of State Legislators, the National Association of Counties and the National League of Cities who expressed the hope that DERA would be funded “at $200 million in [the] Fiscal Year 2007 budget without affecting funding support for other key environmental programs.”(1) We are confident that cooperating on such result-oriented solutions will incrementally yield the health and environmental benefits through cleaner air we all seek.

This solution, however is only one of several actions needed to attain the air quality standards on a reasonable schedule, which is an often-deferred goal. Implementation of the existing particulate matter and ozone standards are a minimum vital step for protecting Delaware. We will describe Delaware’s situation, our actions to control the air pollutants, and the enormous health benefits possible through implementation of these extraordinarily important public health protection measures.

A. Delaware – Small, Precious and Downwind

President Tomas Jefferson dubbed Delaware “The Diamond State” because we are “small but precious.” To which we would add, “downwind.” In few other states is the fate of our air quality decided before we wake up in the morning and start turning on lights or driving cars. As you may know, all of Delaware is currently nonattainment for ozone, and our most populous county, New Castle, is non-attainment for fine particulates. This situation should not obscure the fact that we have made enormous progress improving air quality. We have met the one-hour standard for ozone, and substantially reduced SO2 emissions, especially from the oil refinery in Delaware City, which is one of the few oil refineries with the capability of processing “sour” crude. Thanks largely to a variety of state measures and EPA’s Clean Air Interstate Rule (CAIR) rule and implementation we expect further improvements in air quality. Nonetheless, Delaware will continue to fail to meet the ozone standard in 2010, despite our best efforts. Again the main reason is our down wind location. As with many policy questions, where you stand depends on where you sit. We sit at the end of a conveyor belt of air pollution that is loaded in the mid-west and deliver fully cooked on the Atlantic seaboard. Monday’s rush hour in St. Louis and Cincinnati can become Wednesday’s Ozone alert in Delaware. Part of our routine function as the state air agency is to constantly monitor air quality and provide reports on the Internet. Often, our high pollution levels are measured in southern Delaware where there more acres of soybeans than suburbs, and far more chickens than people or industrial emissions. This observation is no puzzle when you consider upwind sources.

To some, the expected non-attainment is an excuse to kick the can down the road even further. To us, it motivates us to seek other cost-effective controls to control ozone precursors and PM2.5 sources. For example, we are pleased to announce Delaware DNREC Secretary John Hughes recently signed a “Start Action Notice” to initiative rulemaking to reduce emissions from Delaware’s older, high-emitting coal and residual oil fired power plants. This “multi-pollutant regulation will control NOX, SOX and mercury. The goal is to adopt a final regulation by fall 2006. Second, we are regulating industrial boilers. Third, we have just completed permitting of a major source of Volatile Organic Compounds (VOC) – the lightering (off-loading of crude oil) of Supertankers coming out of the Atlantic Ocean into the Delaware Bay before they make their way upriver to refiners in Delaware, Pennsylvania and New Jersey. We are proud that this lightering permit was negotiated in a way that results in a win-win by allowing the lightering company to refit their entire fleet with vapor balancing equipment to capture the lost VOCs, which is a product for them and their customers.

We are pursuing this variety of air pollution controls initiatives because we know the benefits outweigh the costs. We also know that national and regional solutions are necessary to help control air quality in Delaware. We persevere nonetheless knowing we cannot ask others to take action we ourselves are not willing to take.

B. Air Pollution Costs and Benefits: Déjà vu All Over Again

Recent reports (2) of the costs, technical challenges and complexity of meeting Clean Air Act attainment deadlines remind me of the observation of baseball great and philosopher, Yogi Berra, “It’s Deja Vu all over again.” Regrettably, much of the analysis behind these claims has not been subject to the normal peer review process for publication in a scientific journal. More substantively, it fails entirely to consider the substantial benefits to controls and examines only the projected costs. Finally, the complexity of the Clean Air Act is nothing new to those of us who live in this world of air pollution control. We are more sympathetic than most to the desire for simplification. The essential management metric for evaluating the performance of any proposal is the impact on air quality. And by this measure, we cannot support trading off paperwork simplification for dirtier air in the real world. We urge the Committee not to confuse “harmonizing” dates with merely “kicking the can down the road” on improving the air quality and achieving the sustainable health benefits known to be possible.

These “cost-only” studies also have had a strong track record of overstating the eventual costs, whether it was the original acid rain studies or the more recent estimates of New Source Review (NSR) compliance. And on this matter we must also disagree: we do not agree that American engineers lack the skill and creativity to develop innovative technologies and methods for achieving air pollution reductions more cost-effectively than merely extrapolating from current trends. We also stand ready to continue to pursue regulatory streamlining that reduce compliance costs (e.g., paperwork and permitting value stream mapping. In short, we are very bullish on American ingenuity, and have been richly rewarded with our confidence in the past.

We are not insensitive to costs. We live in the communities where our neighbors’ jobs are on the line. However, can not ignore the substantial and subsequent savings derived from health-related costs from air pollution. So, the question is not whether there are costs, but rather “who bears the costs?” There are clear, though less quantifiable, costs to public health that result from failing to address air pollution problems. In conjunction with our state Division of Public Health, Delaware recently released a report on “the Asthma Burden”,(3) which showed a continuing increase in the number of asthma cases. We realize these asthma cases cannot be attributed solely to air pollution. However, it provide local data supporting hundreds of other studies finding a rising tide of asthma that represents a terrible burden on individuals, families, communities, employers and the economy. As you consider various options for potentially adjusting current schedule for compliance, we urge you to consider the other side of the cost formula; the health benefits and subsequent savings derived from controlling air pollution promptly.

We realize there are those who argue that health standards should be subject to strict cost-benefit analysis. We respectfully disagree with this view. However, this is not the questions before us. Over the years, every major, peer-reviewed study has found substantially greater benefits than costs from controlling air pollution, and found greater benefits from air pollution control than virtually any other environmental programs (e.g., oil spill cleanup). Among the most prominent studies was EPA’s “unfinished business report, release in 1987, which found air pollution to be among the highest benefit program in EPA.(4) Few years later, under President George H.W. Bush, EPA’s Science Advisory Board reviewed this assessment more rigorously and found uncertain in the estimate in many areas, except air pollution control.(5) Criteria Air pollutants were ranked as a high risk by the unfinished Business report in the 1980s. In 1990 the Science Advisory Board report on Reducing Risk “…considered to be supported more firmly by the available data than were the rankings for the others.” More recently, in 2003, the White House Office of Management and Budget, Office of Information and Regulatory Affairs, under John Graham, found that one of the most clear examples of an environmental program where the benefits clearly outweigh the costs is in the area of air pollution control.

C. Attainment of Minimum Air Quality Standards – Following the Science

Ozone is essentially highly energized oxygen that contains an extra oxygen atom, which results in a respiratory effect sometimes compared to giving your lungs a sunburn. It is not emitted directly but results from “cooking” precursors like NOX and VOCs in sunlight. Ozone is a strong respiratory irritant that affects healthy individuals as well as those with impaired respiratory systems. It can cause respiratory inflammation and reduced lung function, and can reduce human’s resistance to colds and pneumonia. Ozone also adversely affects trees, crops (soybeans are a particularly sensitive species), and other vegetation. The national agricultural loss from ozone pollution is estimated to be several billion dollars annually.(6) In the 1970s and 1980s scientists realized it was not only the concentration of ozone exposure but also the duration. Consequently, EPA began the lengthy process of developing a revised standard to replace the old “1-hour” standard, with an “8-hour” standard that reflected this scientific consensus about how ozone affects human lungs. It is a valuable lesson to have read scientific journals and heard academics talk about the chronic exposure phenomenon in the 1970s and need to change the short-term standard, only to be involved with implanting a standard to address this issue in 2005. Consequently, when we learn of EPA’s interest in developing a new standard, you must forgive us if we do not reach for our seatbelt.

Like many metropolitan areas, but states, Delaware has been struggling with chronic ozone pollution for years. We have worked diligently for many years to overcome the burden of this pollutant on our citizens. As I mentioned, Delaware’s air quality, statewide, does not meet the standards for ozone, and is not expected to meet the ozone standard until beyond 2010. We know better than most the difficulty in explaining to the lay people that we met the standard that we have been pursuing for years, but the rules changed and that we are now violating a new standard. Essentially, our violations do not reflecting worse air quality, but a change in standard. It is easy to criticize this situation as “changing the goal line.” It is harder to explain the need to use the best science available. But, given a choice between easy public relations and good science, our choice should be clear.

We have worked with OTC states to evaluate CAIR and found it does not adequately produce the needed emissions to reach attainment of the ozone and PM standards in the northeast and mid-Atlantic states. EPA acknowledged that there would be “residual” non-attainment areas after full implementation of CAIR, but detailed modeling suggests strongly that the difference between EPA’s coarse scale modeling and that which was done by the OTC shows a larger gap to fill. In an attempt to derive a solution, a CAIR PLUS alternative was derived and tested. The model rule, corresponding to this alternative, will provide for lower regional EGU emissions through, potentially, a higher NOX and SOX allowance retirement ratio, which will be determined based on SIP quality modeling. The CAIR PLUS concept may also be a cooperative effort with states outside the Ozone Transport Region (OTR), as states beyond the OTR are also concluding that reductions beyond CAIR are needed. Even with this alternative, residual non-attainment areas exist. Considerable area, regional, mobile and local measures, yet to be fully determined, will be needed to finally fill this gap.

Delaware and several other states, have taken steps to meet the 1-hour ozone standard, which are essential to fulfill the 8-hour ozone standard.

Delaware has adopted in coordination with other OTC states that are not specifically identified in the CAA:

1. Architectural and Industrial Maintenance (AIM) Coatings: reduced VOC content of numerous coatings beyond federal requirements.
2. Mobile Equipment: established coating equipment standards to reduce VOC emissions.
3. Gas Cans: required gas cans meet certain performance and permeability standards to reduce VOC emissions.
4. Degreasing: reduced degreaser vapor pressure and instated equipment standards and work practices to reduce VOC emissions.
5. Control of NOX Emissions from Large Boilers: reduced NOX emissions from boilers larger than 100 mmbtu/hr that weren’t well controlled through other programs.
6. Anti-Idling: reduced VOC, NOX, SOX, and DPM emissions from heavy duty vehicles by reducing allowable idling time.
7. Open Burning: instated strict open burning ban during the ozone season.
8. Minor NSR: reduced criteria pollutant and air toxic emissions by subjecting new minor stationary sources to top-down BACT requirements.
9. OTC NOX Budget Program: participated in a regional NOX Cap and Trade program to reduce NOX emissions from power plants (program later replaced by the NOX SIP Call).
10. Adopted several regulations to reinforce EPA-adopted heavy-duty diesel rules.

 

In addition, we have begun work on additional measures, not specifically identified:

1. Stationary Generator Regulation: will reduce criteria pollutant and carbon dioxide emissions from stationary generators.
2. Peaking Units: will reduce peak ozone day NOX emissions from combustion turbines used as electrical peaking units.
3. Refinery Boilers: will reduce NOX emissions from large refinery boilers.
4. Non-Refinery Boilers: will reduce NOX emissions from large non-refinery boilers.
5. Utilities Multi-P: will reduce NOX, SOX, and Hg emissions from Delaware’s coal and residual oil fired electric utilities.
6. Lightering: will reduce VOC emissions from crude oil lightering operations in the Delaware Bay.

 

Finally, we are looking at additional measures where we expect the benefits will exceed the cost of controls. The point is that there is no “silver bullet” solution, but a variety of individual actions that yield success.

2. Soot: Fine Particulates Get in Your Eyes and Deep in Your Lungs

The issue of controlling fine particulates is particularly important to Delaware for a number of reasons. First, and foremost, the air quality in our most populous county is impaired such that it fails to meet the minimum standards for human health protection from the effects of fine particulates. Second, we are keenly aware that we cannot control our “nonattainment” situation alone, without contributions by upwind states. Third, Delaware air is also polluted with toxic chemicals, such as benzene and vinyl chloride,(7) which can be absorbed into fine particles with worse health effects than either pollutant alone.

Fine particulate matter, known as PM2.5, is a complex and harmful mixture of sulfur, nitrogen, carbon, acids, metals and airborne toxics. When breathed in, PM2.5 permanently lodges in lung tissue and causes lung damage and respiratory problems. The fine particles can cross from the lung into the blood stream resulting in inflammation of the cardiac system, a root cause of cardiac disease including heart attack and stroke leading to premature death. PM2.5 exposure is also linked to low birth weight, premature birth, chronic airway obstruction, and sudden infant death. In addition to these negative health impacts, fine particulate matter is the primary cause of reduced visibility. New Castle County’s air quality does not meet the standards for PM2.5, and Kent and Sussex Counties are not much below the standard (currently monitoring about 15 percent). Health studies for fine particles have consistently shown that this pollutant is at the top of the list of concern to health and we understand that EPA’s review of the standard, as mandated by the Clean Air Act is suggesting that the existing standard, only finalized in 1997, is not likely to adequately protect public health and should be tightened. This means that we may need to cut emissions even more than we are currently contemplating in order to provide healthful air to our citizens. All activities that we undertake under the standard as it now exists will help us with attainment of a future standard, whenever it is adopted. This work keeps us on the glide path to timely attainment.

Here again we support the adherence to good science. A compounding effect is that the finer particles attract and retain toxic material much more efficiently than larger particles. At one time, air pollution control was done by controlling “total particulates”, even though scientists have long known that particulates are not all created equal in terms of their ability to reach deep into lungs. Scientists have found that the standard for PM10 (particulate material with a median diameter of 10 microns or less is not adequately protective of public health. The reason appears to be that the finer particles are inhaled readily into the lungs and essentially are never eliminated (exhaled or brought up by cilia with phlegm). In fact, I serve personally as one of the guinea pigs in graduate school in the laboratory of David Swift who was studying this phenomenon. In the 1980s, we pursued control of particulates smaller than 10 microns. Now we know that particulates smaller than 2.5 microns are the most harmful, not only because of the physical ability to reach and lodge deep into lungs, but also because of the ability to behave partly as a fume and partly as a particle and ability to adsorb toxics.

We understand there is some concern with the prospect of adopting a new scientific standard for human health protection, when the implementation of the previous health standard has barely begun. For environmental engineers and scientists, however, this “pipeline of standards and implementation is part of the normal process of careful development of programs to protect human health, and of the perils of litigation that affect these programs. Accordingly, we believe that the new PM2.5 should be adopted with all due alacrity so that the public benefits can be realized through detailed implementation.

We fully realize there is a substantial cost to complying with the air pollution control requirements necessary to meet these new standards. We also realize there is a cost to not complying with these standards. These costs are the often ignored benefits of attaining healthful air quality. We realize the real benefits of controlling PM 2.5 pollution is difficult to quantify and that estimates vary significantly from local epidemiological estimates on one end of the spectrum to the John Locke institute on the other end. We refer you to EPA’s estimate of the health benefits, described in the recent implementation rule for fine particulates,(8) which, of course could not be published without approval by the White House Office of Management and Budget’s Office of Information and Regulatory Affairs:

“…the effects of PM2.5 on public health are serious. Estimates suggest that each year tens of thousands of people die prematurely from exposure to PM2.5, and many hundreds of thousands more people experience significant respiratory or cardiovascular effects. Even small reductions in PM2.5 levels may have substantial health benefits on a population level…EPA has estimated that the monetized health benefits of reducing emissions of pollutants that lead to PM2.5 formation exceed the costs by 3 to over 30 times.”

And the evidence of serious health problems from particulates continues to mount a recent survey of data from 90 urban areas.(9) Again, we do not suggest cost be ignored, but strongly urge that the benefits be weighed as well.

D. CAIR: A Good Start on a National Good Neighbor Policy

The Clean Air Interstate Rule (CAIR) addresses the age-old problem long known to those of us in the dismal science of air pollution – the wind obeys no state boundaries. Commerce may or may not be interstate requiring a federal role, but air pollution cries out for a federal role of an intestate activity – air pollution.

All states, in cooperation with the EPA, have made significant strides in improving the quality of the air, and made equal strides in understanding what forms of control offer the most effective path to success, both from ease of implementation and from an economic view. We have managed to improve air quality by reducing emissions while enjoying increases in GDP and experiencing significant growth in vehicle miles traveled. Since 1970, we have cut emissions that cause soot, smog and acid rain by more than half, even while our nation’s economy has grown by 187% - clear evidence that a growing economy and environmental results can, in fact, go hand-in-hand. (Administrator Johnson’s speech on 8/4/2005 at Adirondack Council 30th Anniversary, Essex, NY) We need to continue this pattern and bring about healthful air to our citizens as expeditiously as possible.

However, we know more needs to be done. The understanding of the problem brings with it the double-edged sword or recognition of the extent of the problem. Attainment of NAAQS is clearly more vexing than we thought when the earlier Clean Air Acts were passed. Even with the 1990 Amendments, which we hoped would address the ozone problem. Despite concerted effort, the problem persists. We need, and fervently ask for your support to allow us to properly regulate major sources, and most importantly, those sources that are causing our population the most harm. Some issues like intestate transport require a strong federal role while a variety of individual solutions are more appropriately tailored by states. We have taken action of oil tanker lightering because it is significant source of VOC pollution. We know that some states like Missouri, are legally restricted from controlling pollution more stringently than the federal government, and so chronic problems like lead deposition form smelter persists because of EPA inaction on a problem that is restricted to few states. Surely, this is not the time to consider extending attainment deadlines, or hobble states ability to take action. Already action on these standards has been delayed by litigation, that neither cleared the air for better science or law nor for people’s health.

The CAA established a clear path to ameliorate these problems. The Act provides the states with the mechanism to accomplish this task by identifying the culprit areas and making sound estimates of the sources within the areas most likely to be causing the problem. Areas experiencing nonattainment have three years to develop State Implementation Plans (SIPS), with the fine particulate matter SIP due in April, 2008, and the ozone SIP due in June, 2007. The preparation and adoption of past SIPs by each State containing a nonattainment area are grueling tasks, but with very limited exceptions, and only in extraordinary circumstances, have these SIPs not been submitted by the appointed date. A combination of detailed information on the amount of air pollution entering the state, plus information on the amount of pollution generated internally, constitute the cornerstone of the SIP preparation. Knowing how serious the pollution problem is, and what is causing the problem, states can perform complex modeling to determine how much reductions in emissions are necessary to result in an attainment condition. Selection of measures to effect that reduction in emissions, whether locally or regionally, is the final major step in the process. When regional emissions are the major contributor, regional solutions must be developed. One example of this activity is the exemplary work accomplished by the Northeast Ozone Transport Commission (OTC), including all states from Maine to Virginia, working together for a common cause. Using the mechanisms of MOUs and Resolutions, members of the OTC work together to develop control measures that benefit wide areas and not strictly one state.

It is EPA’s responsibility and authority to move the preparation of SIPs as expeditiously as possible, and provide adequate support by developing guidance documents, in a timely manner, which states can use to move forward with their work on the SIPs. This mandate, as clearly defined in the Clean Air Act, forms the backbone for the important relationship between the federal, state and local governments, and allows the entire process to move forward effectively and efficiently. According to the recently proposed fine particle standard implementation Rule, it is the clear responsibility for the federal government to promulgate rules on utilities and other large sources, mobile sources, ports, rail operations and others, that produce a universally positive impact on reducing emissions. Subsequent to that activity, and depending on how severe a nonattainment condition remains, state and local areas must fill in the gap with more localized measures that are not pre-empted by federal authority.

EPA has taken a universally effective first step with the adoption of the CAIR rule. Unfortunately, it is only a first step. We believe EPA has the authority and a responsibility to do much more. Modeling performed by both state and regional entities have determined that the results not only fall short of producing the needed emission reductions but also are timed in such a manner that little assistance will be gleaned from these actions in time to attain by the required, and I might note, very reasonable schedule, mandated by the Clean Air Act. While EPA has taken an important first step to address transport, we are still concerned that the agency has not done enough. CAIR leaves over 9 million citizens in the North East alone with unhealthy air after its implementation. But even with the most stringent controls we have tested thus far, more than two million citizens remain experiencing unhealthy air. We believe the compliance deadlines are too long, the emissions caps are too weak, and an insufficient number of sources are covered. Additionally, we are troubled that EPA is intending to weaken an important regulatory tool under Section 126 of the Clean Air Act for addressing interstate transport. Now that regions and states recognize the shortcomings of CAIR, work is underway to fill those gaps. The tools necessary to accomplish these objectives must not be taken away from the states. Actions such as preemption of state authority on small engine controls, accomplished by legislated activity and prevention of state’s ability to adopt mobile source rules identical to those of California, severely hamper a state’s ability to do it’s job. Very simply put, if a state is able to pas muster through its normal adoption process, which is both very open and rigorous, there is no reason to prevent a state from doing so.

For example, the northeast and mid-Atlantic states, under the auspices of the OTC, are currently developing a CAIR plus strategy which will result in considerably more emission reductions, from the most appropriate geographical locations, to make a substantial improvement on the original CAIR Rule. The kinds of improvements on the original CAIR framework include nonroad emission control and fuel requirements, and the tightening of the existing controls on stationary sources. Another example of measures directed to improve upon the CAIR framework are being accomplished under the auspices of other regional organizations in the Midwest and the Southeast.

We fully realize there is a substantial cost to complying with the air pollution control requirements necessary to meet these standards. We also realize there is cost to not complying with these standards. These costs are the often ignored benefits of attaining healthful air quality.

At this point in time, our largest and overarching concern is that the federal government should refrain from interfering with our ability to adopt more stringent controls than those already promulgated. These measures are ones which we feel can most efficiently and cost-effectively fill the gap between the benefits of CAIR, which again, we concur are substantial, and that amount of reductions in emissions necessary to result in widespread attainment. There have been too many instances when opportunities have been lost when apparently artificial limits have been placed on measures which would affect substantial positive impacts on the wide field of emission reduction possibilities. We ask that you allow the states to do the necessary evaluation and take whatever actions necessary to reach attainment, and not extend timelines and remove any existing authorities that states now have.

Finally, on this day before Veterans Day, I would be remiss if I did not acknowledge the contribution of our men and women of the armed Force who have contributed to our understanding of the science of fine particles and human health. The U.S. Army supported the laboratory of the Dr. David Swift at The Johns Hopkins University, and much of the work at the Inhalation Toxicology Research Laboratory at the Sandia National Laboratory in Albuqurque, New Mexico. Without this critical contribution by this military-sponsored research, our appreciation of the role of fine particles in human health would not be great as it is today. God bless our men and women of the Armed Forces and all their contributions to the people of the United States and people who yearn to breath free everywhere.

Thank you for the opportunity to present these views. I would be happy to answer your questions.

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1 Joint letter from the National Governors’ Association, the National Conference of State Legislators, National Association of Counties and the National League of Cities to President George W. Bush, November 2005.

2 For example, NERA Economic Consulting for the American Petroleum Institute, Economic Impact of 8-Hour Ozone Attainment Deadlines on Philadelphia Region, September 2005 (released November 7, 2005).

3 The Burden of Asthma in Delaware, Delaware Health & Social Services Division of Public Health, and Department of Natural Resources and Environmental Control, August 2005

4 EPA, Unfinished Business: A Comparative Assessment of Environmental Problems, 1987

5 EPA, Reducing Risk: Setting Priorities and Strategies for Environmental Protection, SAB-EC—21, September 1990. and Stevens, William K., “What Really Threatens the Environment”, New York Times, January 29, 1991.

6 (61 FR 65742, December 13, 1996, National Ambient Air Quality Standards for Ozone: Proposed Decision
An examination of the monetized benefits reported above indicates that most of the estimated benefits accrue from attainment of the 8-hour, 0.08 ppm primary standard with a smaller incremental improvement obtained by the addition of a seasonal secondary standard. The projected national approximations for commodity crops and fruits and vegetables suggest that benefits on the order of 1 to more than 2 billion dollars would result from the proposed 8-hour, 0.08 ppm primary standard, alone or in combination with a seasonal secondary standard.

7 Delaware Division of Public Health and Department of Natural Resources and Environmental Control, Delaware Air Toxics Assessment Study, phase I final report, August 2005.

8 Proposed Rule To Implement the Fine Particle National Ambient Air Quality Standards; Proposed Rule 70 Fed. Reg. (210) 65984-66067, November 1, 2005.

10 JAMA study Pope CA 3rd, Burnett RT, Thun MJ, et al., “Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution,” Journal of the American Medical Association (JAMA), 2002;287:1132-1141; Brook RD, Brook JR, Urch B, et al. Inhalation of fine particulate air pollution and ozone causes acute arterial vasoconstriction in healthy adults. Circulation. 2002;105:1534-1536; and Ozone and Short-term Mortality in 95 U.S. Urban Communities Bell, M.L., et al. (2004). JAMA 292, p. 2372-2378.