


NMMAPS provides the best evidence to date for fine particles' link to a broad range of effects leading to hospitalization. While previous studies established the link between fine particles and asthma-related hospital admissions, including a 1999 study which confirmed the relationship between increases in fine particle pollution and hospital admissions for asthma, NMMAPS found robust associations between fine particle levels and increased hospital admissions for cardiovascular disease, pneumonia, and chronic obstructive pulmonary disease.
Several other important studies also tie fine particle levels to emergency room visits. For example, fine particles were associated with emergency room visits for asthma in Seattle, Washington; Barcelona, Spain; and Steubenville, Ohio. Studies have linked air pollution with both hospital admissions and emergency room visits. There is more data on hospital admissions that allows researchers to derive more complete estimates. Abt Associates based its emergency room visit estimates solely on asthma-related emergency room visits estimated in studies. Estimates of emergency room visits for other respiratory-related diagnoses must await additional studies. Thus, the estimate for asthma-related emergency room visits likely understates the total attributable to power plants.
While these studies of hospital admissions and emergency room visits provide evidence that exposure to fine particles is directly associated with asthma attacks, researchers have also examined the relationship between air pollution and less severe asthma attacks that do not result in hospitalization. Studies in Denver, Los Angeles, and the Netherlands found that substantial increases in asthma attacks were linked with fine particle exposure.
Several studies in the mid-1990's provide evidence that regular exposure to particle pollution over a number of years also gives rise to the development of chronic bronchitis. These studies have been undertaken with groups of Seventh-Day Adventists, a religious order that forbids smoking, in order to control for smoking as a factor that could confound the health effects observed. Similarly, a study of 13,000 children ages 8-12 found that higher levels of fine particle pollution were related to acute bronchitis.
Many other studies have also found a link between fine particle pollution and a whole range of well-known upper and lower respiratory symptoms associated with air pollution including: deep, wet cough; running or stuffy nose; and burning, aching, or red eyes. Associations between fine particles and more general measures of acute disease have also been found. For example, one study evaluated the impact of fine particle levels on lost work days from workers calling in sick, an association that suggests an impact of air pollution on the U.S. economy, while other studies link particles and non-work restricted activity.
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New Research Links Fine Particle Pollution to Heart Attacks Extensive new research published over the past year finds that fine particles at levels routinely found in many U.S. cities may trigger sudden deaths by changing heart rhythms in people with existing cardiac problems. While further research is needed, these early studies are extremely important because cardiovascular disease is the number one killer in the United States, responsible for nearly half of all deaths. While heart rhythms in healthy persons remain largely unaffected by fine particle pollution, for those with existing heart disease fine particle exposures could have deadly consequences. The threat seems particularly acute for elderly people who have existing heart arrhythmia-a life-threatening condition of rapid, skipped or premature beats-or the combination of a weak heart and lung disease such as asthma. The studies suggest that people are dying within 24 hours after elevated particulate matter exposures. About a dozen major scientific studies in the United States, recently completed or underway, are turning up evidence of heart pattern changes in animals exposed in laboratories and in elderly people tested in nursing homes. |
The Clean Air Task Force commissioned Abt Associates, the consulting firm relied upon by U.S. EPA to assess the health benefits of many of the agency's air regulatory programs, to quantify the power industry's share of the toll of death and disease from fine particles in the U.S. The objective of the study was to quantify the health impacts of fine particles from power plants, as well as the expected benefits (avoidable deaths, hospitalizations, etc.) of policies that would require all power plants to meet the same modern emission standards. For comparison, the study also estimated the health effects attributable to fine particle pollution from all diesel trucks, buses, locomotives, and construction equipment in the U.S. The health endpoints analyzed included death, hospitalizations, emergency room visits, asthma attacks, and a variety of lesser respiratory symptoms.
To analyze the avoidable health impacts of fine particles based on existing and hypothetical policy scenarios, the Clean Air Task Force asked Abt Associates to run three cases using methods developed for and employed by the U.S Environmental Protection Agency, extensively reviewed by EPA's Science Advisory Board, and accepted by the U.S. Office of Management and Budget in a variety of regulatory impact and assessment contexts.
In its analysis, Abt Associates assumed full implementation of the power industry's current air pollution reduction commitments, even though all of the required emission reductions have not yet occurred. The base case assumed full implementation of EPA's Summer Smog rule (i.e., the NOx SIP Call) and implementation through 2007 of the Acid Rain program. Abt Associates analyzed the following scenarios:
Abt Associates (health endpoint assessment and damage valuation) led the study team with support from ICF Consulting (power system economics and air quality modeling), and the E. H. Pechan (emissions and air quality modeling).
The first module of the model involves power system economics and asks the question: how will the power system respond to the imposition of the costs of cleanup? Possible compliance responses by the plants include reducing emissions through emission control equipment, obtaining emission reduction credits from other plants that "overcontrolled" their emissions relative to their required emission reduction levels, reduced utilization of the plant, or retirement and replacement with other sources of electricity. The analysis assumed that the power sector will meet the proposed pollution reduction goals in the most cost-effective manner available and provides critical information on the spatial distribution of power plant emissions before and after cleanup. ICF Consulting, EPA's power system modeling consultant, ran its Integrated Planning Model (IPM) to determine the spatial distribution of emissions under the various scenarios. In running the model, ICF Consulting used inputs and assumptions consistent with EPA's Clean Air Power Initiative (CAPI) modeling analysis and other recent regulatory impact work.
The outputs from the IPM provide the power plant emission inputs to the air quality modeling work performed by ICF and by Pechan. First, they assembled the emissions inventory for all non-power plant sources of NOx, SO2 and direct particulate emissions. Using the power plant emissions inputs from ICF Consulting, Pechan and ICF ran EPA's PM air quality models: Source-Receptor matrix (used to model the NOx SIP Call and other regulatory actions) and Regional Emission Modeling System for Acidic Deposition (REMSAD) (approved by EPA's science advisory board and used in the Clean Air Act cost-benefit study). Both air quality models were used to estimate the baseline fine particle contributions attributable to the power plants and the reductions in pollutant concentrations due to the targeted reductions. The inputs and assumptions used by Pechan and ICF are consistent with recent projects performed by Pechan and by ICF for EPA, such as the regional NOx rule (SIP Call), automobile emissions standards (Tier 2), and other similar analyses. The health effects estimates reported here are based on the REMSAD modeling outputs.
The air pollution concentration outputs from ICF and Pechan's air quality analysis provided the inputs for Abt Associates' health effects modeling. Then utilizing health studies described above which link changes in ambient fine particle concentrations to changes in risk of mortality and morbidity, pollution concentration-response functions were derived that quantify the relationship between the forecasted changes in exposure and the expected changes in specific health effects. Abt Associates then used the modeled changes in pollutant concentrations (from the base case to the emission reduction scenarios) to estimate the power plant-attributable health impacts from each. The difference between the base case and the emission reduction scenario yielded estimates of the health benefits (or avoided adverse impacts).
Once the avoidable health impacts were determined, the monetary value of each of the various health endpoints was estimated through economic valuation techniques previously used in EPA analyses. Given the attributable and avoided health impacts calculated, Abt Associates tallied the health damages - from lost work and cost of emergency room care, to the statistical value of human lives lost from power plant emissions - and estimated the benefits of the health impacts avoided under the cleanup scenario. The methodology employed by Abt Associates was consistent with current and previous damage valuation work for EPA, and has been extensively reviewed by the EPA Science Advisory Board.
These compelling findings come at a time of growing public concern over power plant pollution. From Acid Rain, to summer smog, to the dirty haze that hangs over our national parks and wildlands, to the mercury contamination of the fish we eat, to the thre at posed by global warming, power plants' contribution to a host of environmental ills is better understood than ever. No other single industry comes close to matching the variety and magnitude of public health and environmental impacts as those from elec tric power plants.
Fortunately, U.S. EPA and several states have begun to focus on mitigating the myriad problems of power plant pollution:
Most importantly, federal legislation now pending would reduce particle-forming sulfur dioxide and nitrogen oxide emissions by 75 percent from 1997 levels and significantly reduce mercury and carbon dioxide emissions. Recently, the Environment and Public Works Committee of the U.S. Senate began hearings on the issue of comprehensive power plant cleanup. Given the uncertainty facing the industry from the combination of future environmental requirements and the advent of electric industry deregulation, eve n some of the largest polluting power companies have called for comprehensive legislation to clearly spell out their air pollution reduction commitments into the foreseeable future.
Old Dirty Power Plants Must Reduce Fine Particle-Causing Emissions
Polluting coal-fired power plants must be made to comply with modern emissions control standards. In addition, the nation's power fleet should be held to nationwide caps on all four of the key power plant pollutants, including nitrogen oxides, sulfur diox ide, mercury and carbon dioxide. Reducing power plant NOx and S02 emissions by 75 percent from 1997 emissions levels will dramatically reduce fine particle pollution so we can all breath e easier. A 75 percent reduction is necessary to protect our health and is readily achievable. The deaths, hospitalizations and lost work time caused by fine particles from power plants can be reduced comprehensively only when the Clean Air Act's 30-year loophole for old, dirty power plants is finally closed. Requirements such as these can ensure that U.S. energy policy better accounts for the public health and environmental costs associated with electricity production and will propel us toward a more sus tainable energy future that relies increasingly on renewable energy resources and conservation.
Now that policymakers know that simply cleaning up power plants to modern emission standards could save over 18,000 lives per year, there is no excuse for further delay. Protection of public health compels swift action to dramatically cut the death and disease visited upon Americans each year by these dirty, antiquated plants.
Written by: Clear the Air. Initiated by The Pew Charitable Trusts through a grant to Pace University, Clear the Air is a joint project of three leading clean air groups, the Clean Air Task Force, National Environmental Trust and the U.S. PIRG Education Fund.
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