EASTERN SIERRA LEAGUE OF WOMEN VOTERS
                             P.O Box 1496, bishop, california 93515-1496                                               

                                                                                                                         March 24, 2006

Docket ID No. EPA-HQ-OAR-2001-0017

U. S. Environmental Protection Agency, Mailcode:6102T

1200 Pennsylvania Avenue, NW

Washington, DC 20460

The League of Women Voters of the Eastern Sierra has the following comments and suggestions for revisions to the National Ambient Air Quality Standards for Particulate Matter (Docket ID No. EPA-HQ-OAR-2001-0017) that appeared in the January 17, 2006 Federal Register.

I. SUMMARY

A. We oppose restricting the PM10-2.5 standard to Census Bureau designated urbanized areas of more than 100,000 persons, because this eliminates more than 98% of the area of the United States and 37% of the population. The other four proposed restrictions described in Docket EPA-HQ-OAR-2004-58 (Federal Register January 17, 2006, pages 2736 through 2738) on the applicability of the standard eliminate even more areas. A national standard must be imposed impartially. All persons exposed to the harmful material should be protected equally. The proposed standard is not a national standard since it does not apply everywhere where people are exposed to the harmful pollution. We particularly oppose forbidding monitors near large sources of the very PM10-2.5 that the new standard judges to be harmful.

B. We disagree with the conclusion that all coarse PM10-2.5 outside of Census Bureau-identified urban areas of population greater than 100,000 persons is composed of only “uncontaminated natural crustal material” that does not have health effects.

C. We oppose elimination of the PM10 standard before PM10-2.5 SIPs are approved and controls are in place, since this could result in 8 to 10 years of no coarse particle protection in the United States.

D. We support including the Owen Valley Planning Area, a serious non-attainment area for PM10 in California, in those areas where the 24-hour PM10 standard will be retained, since 24-hour PM10-2.5 levels could reach 3000 ug/m³ if uncontrolled and the particulates contain toxics, metals, and sulfate salts.

E. We oppose the use of the 98^th percentile form of the PM2.5 and PM10-2.5 standards, because it allows 21 days of harmful high values every three years. This may bring stability to regions where levels are nearly the same every day, but denies protection in areas with episodic pollution. For example, ski areas with wood smoke problems aggravated by weather conditions and an influx of skiers on weekends can have serious PM2.5 problems on some weekends and never trigger protection since the three year average of the 8th high day may meet the standards

F. We support retaining the PM10 indicator and subtracting PM2.5 greater than 35 ug/m³ to compare to the standard, but we do not support restricting the standard to urban areas.

G. We oppose the exemption for agricultural and mining operations, since it has not been shown that the emissions from these sources do not contain metals, cyanide (heap leach), pesticides and herbicides.

II. PROPOSED DECISIONS ON PRIMARY PM 2.5, PM10 and PM10-2.5 STANDARDS

A. Urban Particulate Matter Standard On page 2667 “the Administrator notes that identifying” the proposed PM10-2.5 standard “as an ‘urban’ thoracic coarse particle indicator could be misconstrued as meaning that the standard is limited to certain geographic locations and, thus, not a national standard.” and “In short, the indicator is not defined by nor limited to any specific geographic area, but includes the mix of PM10-2.5 in any location that is dominated by these sources” (page 2668). However, 40 CFR Parts 53 and 58, which appeared in the same Federal Register (Docket ID No. EPA-HQ-OAR-2004-0018) include a five part test, all parts of which must be satisfied, in order for a monitoring site to be suitable for comparison to the PM10-2.5 NAAQS, and thus for an area to be protected by that standard (pages 2736 through 2738, Attachment 1)

The first test excludes all the geographical area not included in a “U.S. Census Bureau-defined urbanized area that has a population of at least 100,000 persons”. Only 2% of the area of the United States meets these requirements. (Attachment 2) The second test requires the census block group to have a population density of at least 500 persons per square mile, further reducing the area. The third test is that it is a “population-oriented site”. The fourth test is that there is no nearby large emission source of the very PM10-2.5 the standard is designed to control “Even if there are people living or working at the monitor site, thus qualifying it as population-oriented…”. (page 2738) The fifth test is that a “site-specific assessment shows that the ambient mix of PM10-2.5 sampled at that site would be dominated by resuspended dust from high-density traffic on paved roads and PM generated by industrial sources and construction sources, and would not be dominated by rural windblown dust and soils and PM generated by agricultural and mining sources.”

These restrictions disqualify the standard as a national standard, since it is restricted to certain geographic areas. Areas with smaller populations but the same exposure to harmful pollution (tests 1 and 2) or those with large populations but a higher exposure to harmful pollution near sources (test 4) will not be protected. In the interest of equal protection under the law, if a standard is defined by size and chemical constituents that are harmful, it should apply everywhere those conditions exist and not be restricted to urban populations. All rural areas are not the same. If an area can show that the crustal particles are contaminated with toxics, metals, salt, or any other of the so-called “urban” pollutants, it should be able to invoke the standard to protect rural residents. In the interest of protection of public health, an area should have to show that its PM10-2.5 is uncontaminated crustal material in order to be exempt from controls, not that its PM10-2.5 is contaminated in order to be protected from harm.

B. Health Effects

The discussion of health effects (pages 2654 through 2662) demonstrates that short-term exposure to thoracic coarse particles can be linked to health effects, including respiratory morbidity and effects on the cardiovascular system, and may increase mortality. Since “the available epidemiologic studies that have used PM10-2.5 did not evaluate associations with specific components of thoracic coarse particles”, the evidence that “crustal material in non-urban areas” is “less likely to have adverse effects, at least at lower concentrations” is weak. It relies primarily on one study in Spokane, where the crustal material, amounting to only 221 ug/m³ of PM10, did not increase mortality. However, the Staff Report concludes that the connection between PM10-2.5 and mortality is weak (page2658), leading to the possibility that the absence of health effects of the dust storms in Spokane is caused by comparing to a health effect that is only weakly associated with PM10-2.5. This amount and quality of evidence is insufficient to eliminate more than 98% of the area of the United States from protection under the PM10-2.5 standard.

The fact that most studies were done in urban areas does not support the assumption that the health effects are confined to urban areas. If the evidence inconclusive, the benefit of doubt should go to the protection of public health. The proposed PM10-2.5 standard does not meet the requirement of an “adequate margin of safety intended to address uncertainties associated with inconclusive scientific and technical information available at the time of standard setting, and to provide a reasonable degree of protection against hazards that research has not yet identified” (page 2622).

We support retaining the PM-10 24-hour standard in areas that have not attained that standard in order to preserve controls required or already in place, since they are often the only existing controls on PM2.5 and P10-2.5 at this time. PM-10 standard requirements should not be revoked in any areas until the PM2.5 and PM10-2.5 SIPs are approved and controls are in place. To revoke the PM10 standard when the PM10-2.5 standard is approved guarantees at least 5 years of back-sliding until the new PM10-2.5 controls are in place. For example, there have been no PM-2.5 SIPs approved by EPA Region 9 since the standard was adopted in 1997. If PM-10 had been abandoned in 1997, there would have been no controls on PM for 8 or more years.

Section 172(e) of the Clean Air Act requires controls be required in areas that did not meet the existing standard at the time it was relaxed. Since coarse particle controls are proposed to be eliminated in 98% of the United States, it cannot be argued that the standard has not been relaxed in those areas. Compliance with 172(e) must be required at the same time the coarse particle standard is eliminated in order to avoid back-sliding.

On page 2668 the Administrator solicits comment on other classes of sources that should be included or excluded from the indicator. Since the health effects of the “urban” mix of PM10-2.5 are associated with contaminants such as metals, toxics and salts (page 2665), sources in rural areas that contain such contaminants should also be included. Otherwise, the Administrator has determined that only persons residing in densely populated areas deserve protection from the harmful health effects of contaminated PM10-2.5. This discriminates against rural residents exposed to the constituents of the “urban” mix and against urban residents located near large sources of the “urban” mix pollutants.

For example, particles in the PM10-2.5 range from Owens Dry Lake in California are composed of 17% of sulfate salts, and contain 250 ppm of arsenic, and 40 ppm of cadmium and nickel, contaminants of concern in urban areas. Concentrations of PM-10 in the town of Keeler, before controls were required, could reach above 3000 ug/m³. (See comments by Great Basin Unified Air Pollution Control District, February 10, 2006) If rural areas are excluded from health protection under the PM10-2.5 standard, and the PM10 standard is revoked, these harmful levels will reappear.

Health Effects are shown to increase 5-15%/25ug/m³ PM10-2.5 ( page 2657)
for respiratory hospital admissions, 1-10% per 25ug/m³ for cardiovascular hospital 
admissions (page 2657), and 3-8%per 25ug/m³ for cardiovascular mortality (page 2658)

The effects from Owens Lake dust storms would then be 100 to 1500% higher for morbidity and 300 to 800% higher for mortality than Spokane. Such high levels cannot be ignored, since the evidence does not eliminate health effects from high concentrations of rural PM10-2.5 (page 2659).

E. Form of PM Standards

The proposed form of the PM2.5 and PM10-2.5 standards, the 98th percentile three year average, is inappropriate for areas with episodic air pollution problems. For example, ski areas in mountainous regions that experience inversions and an influx of population on weekends and holidays can have very high concentrations of wood smoke on some days. The seven highest days in a year can be very harmful, but are not controlled under the 98^th percentile form of the standards. Wood smoke contains toxics and carbon, constituents of concern in the proposed urban PM10-2.5 standard.

Since an association is well established between short-term exposure to PM2.5 and mortality and morbidity, the standard should be designed to protect against all exposures to high concentrations. However, those areas with occasional very high levels are unprotected by the proposed form of the standards. We recommend the one exceedance per year form for PM standards.

F. PM10 Minus PM2.5 Greater than 35ug/m³ Unqualified Indicator (page 2673)

The PM10-2.5 discussion states “The limited available information is not sufficient to define an indicator for thoracic coarse particles solely in terms of metrics other than size-differentiated mass, such as specific chemical components.” (page 2665, point 4). The present attempt to define a PM standard by composition as well as size when the data are not there to determine precisely what composition causes the health effects will lead to a situation of reduced health protection for most of the United States, and should be abandoned. We support retaining the PM10 standard and subtracting PM2.5>35ug/m³. This standard should apply everywhere this number is greater than 70ug/m³, or some other number equivalent to the protection that the PM10 standard gave. Otherwise, there will be back-sliding in at least 98% of the United States.

G. Agricultural and Mining Exemptions

These sources are eliminated based upon the assumption that they emit only uncontaminated natural crustal materials that have not been shown to have significan^t health effects. “The limited evidence does not support either the existence or the lack of causative associations for community exposures to thoracic coarse particles from agricultural or mining industries.” (page 2667). However, standards are supposed to contain an “adequate margin of safety intended to address uncertainties associated with inconclusive scientific and technical information available at the time of standard setting, and to provide a reasonable degree of protection against hazards that research has not yet identified” (page 2622) This requirement has not been met.

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Last updated: March 19, 2006.