A Great Opportunity to Strengthen Air Quality Standards
Written Comments by Lone Star
Chapter Sierra Club
September 5, 2007
Docket No. EPA-HQ-OAR-2005-0172
U.S. Environmental Protection Agency (EPA)
Mail Code 6102T
1200 Pennsylvania Ave., NW
Washington, D. C. 20460
Enclosed are the comments of the Houston Regional Group and Lone Star Chapter of the Sierra (Sierra Club) regarding the proposal to change the National Ambient Air Quality Standard (NAAQS) for ozone, Docket ID Number EPA-HQ-OAR-2005-0172.
The Sierra Club agrees with the following statements from the July 11, 2007 Federal Register Notice regarding this proposal:
1) “The requirement that primary standards include an adequate margin of safety was intended to address uncertainties associated with inconclusive scientific and technical information available at the time of standard setting. It was also intended to provide a reasonable degree of protection against hazards that research has not yet identified.” Page 37820
2) “Thus, in selecting primary standards that include an adequate margin of safety, the Administrator is seeking not only to prevent pollution levels that have been demonstrated to be harmful but also to prevent lower pollutant levels that may pose an unacceptable risk of harm, even if the risk is not precisely identified as to nature or degree.” Page 37820
3) “A number of population groups have been identified as potentially susceptible to health effects as a result of O3 exposure, including people with existing lung diseases, including asthma, children and older adults, and people who have larger than normal lung function responses that may be due to genetic susceptibility. In addition, some population groups have been identified as having increased vulnerability to O3-related effects due to increased likelihood of exposure while at elevated ventilation rates, including healthy children and adults who are active outdoors, for example, outdoor workers, and joggers. Taken together, the susceptible and vulnerable groups are more commonly referred to as “at-risk” groups”. Page 37825
4) “Controlled human exposure studies have shown that O3 induces a variety of health effects, including: lung function decrements, respiratory symptoms, increased airway responsiveness, respiratory inflammation and permeability, increased susceptibility to respiratory infection, and acute morphological effects.” Page 37827
5) “Overall, the Criteria Document concludes that positive and robust associations were found between ambient O3 concentrations and various respiratory disease hospitalization outcomes, when focusing particularly on results of warm-season analyses … These positive and robust associations are supported by the human clinical, animal toxicological, and epidemiological evidence for lung function decrements, increased respiratory symptoms, airway inflammation, and increased airway responsiveness. Taken together, the overall evidence supports a causal relationship between acute ambient O3 exposures and increased respiratory morbidity outcomes resulting in increased emergency department visits and hospitalization during the warm seasons.” Page 37832
6) “The Criteria Document … concludes that, taken together the overall evidence supports the inference of a causal relationship between acute ambient O3 exposures and increased respiratory morbidity outcomes resulting in increased emergency department visits and hospitalizations during the warm season.” Page 37845
7) “EPA’s reanalysis of the data from the most recent study shows small group mean decrements in lung function responses to be statistically significant at the 0.060 ppm exposures level …”. Page 37864
8) “Just meeting the current standard results in an aggregate estimate of about 20% of asthmatic or 18% of all school age children likely to experience exposures of concern at or above the 0.070 ppm benchmark level using the 2002.” Page 37867
9) “At the benchmark level of 0.060 ppm, about 70% of all or asthmatic school age children are estimated to experience exposures of concern at this benchmark level for the aggregate of the 12 urban areas associated with 2002 O3 levels.” Page 37867
10) “… the CASAC (Clean Air Scientific Advisory Committee) O3 Panel, with full endorsement of the chartered CASAC unanimously concluded that there is “no scientific justification for retaining” the current primary O3 standard, and the current standard “needs to be substantially reduced to protect human health, particularly in sensitive subpopulations.” Page 37869
11) “Further, the CASAC letter noted that “there is no longer significant scientific uncertainty regarding the CASAC’s conclusion that the current 8-hour primary NAAQS must be lowered.” Page 37869
12) “The Panel also noted that “scientific uncertainty does exist with regard to the lower level of O3 exposure that would be fully protective of human health,” concluding that ”it is possible that there is no threshold for an O3-induced impact on human health and that some adverse events may occur at policy-relevant background.” Page 37869
13) “… the Administrator proposes that the current standard does not protect public health with an adequate margin of safety and should be revised to provide additional public health protection.” Page 37869
14) “In addition, some of these commenters also noted that the World Health Organization’s guidelines for O3 air quality are in the range of 0.061 to 0.051 ppm.” Page 37880
15) “Specifically, it can reduce the market value of certain leafy crops … and affect the aesthetic value of scenic vistas in protected natural areas such as national parks and wilderness areas.” Page 37887
16) “A broad multi-state region in the east … and west … TX) were still predicted to have O3 levels above the W126 level of 21 ppm-hour.” Page 37892
17) “Most areas were predicted to have O3 levels below the W126 level of 21 ppm-hr, although some areas in the east … and west … TX) were still predicted to have O3 levels above the W126 of 13 ppm-hour.” Page 37892
18) “On these bases, the Administrator proposes that the current secondary standard is inadequate to protect the public welfare from known and anticipated adverse O3-related effects on vegetation and ecosystems.” Page 37899
19) “The level of ambient O3 that is requisite in a federally designated Class I area may be lower than the level that is requisite in a cropland area.” Page 37903
The Sierra Club comments as follows on the proposal:
1) The Sierra Club opposes keeping the present primary ozone NAAQS of 0.08 ppm over 8-hours. The current ozone standard is not protective of both human health and welfare, including crops, wilderness, and other natural areas.
2) The Sierra Club opposes the proposal to set the primary ozone NAAQS between 0.070 ppm and 0.075 ppm over 8-hours as not protective of human health.
3) The Sierra Club supports setting the primary ozone NAAQS between 0.060 ppm and 0.070 ppm over 8-hours with preference toward the lower end of this range so that the ozone standard is as fully protective as possible of human health, given the results of scientific research that has been completed, analyzed, and reviewed, to date.
4) The Sierra Club supports changing the primary ozone NAAQS so that it is effective to the thousandths place (rounding off to three decimal places) to ensure that the ozone standard is as protective as possible of human health.
5) The Sierra Club supports changing the ozone NAAQS secondary standard to a cumulative, seasonal standard expressed as an index of the annual sum of weighted hourly concentrations, cumulated over 12 hours per day (8 am to 8 pm) during the consecutive 3-month period within the ozone season with the maximum index value set at a level within the range of 7 to 21 ppm-hours. The Sierra Club preference is for setting the secondary ozone standard closer to the lower end of this range to ensure that welfare, including crops, wilderness, and other natural areas are fully protected.
The Wilderness Act requires a standard of “untrammeled” by humans (uncontrolled and un-manipulated) and preservation of “natural conditions”. By emitting air pollutants that create ozone in concentrations that are deleterious to vegetation and ecosystems in wilderness we violate the Wilderness Act. A more stringent secondary ozone NAAQS results in less trammeling and more natural conditions in wilderness and also will benefit other natural areas that are not designated as wilderness. Some of these other areas include Sam Houston National Forest, Big Thicket National Preserve, San Bernard and Brazoria National Wildlife Refuges (which have Columbia Bottomlands forest), Trinity River National Wildlife Refuge, and non-Class I wilderness areas like Little Lake Creek Wilderness Area in Sam Houston National Forest.
6) The Sierra Club prefers one secondary ozone standard since protection of crops, wilderness, and natural areas are all important and so the public will not be confused by a plethora of standards.
7) The Sierra Club supports additional required ozone monitoring for rural areas, areas near wilderness (like Little Lake Creek Wilderness Area in Sam Houston National Forest), and near other natural areas like Sam Houston National Forest, Big Thicket National Preserve, and Brazoria, San Bernard, and Trinity River National Wildlife Refuges because there is a dearth of ozone monitoring in or near such areas.
8) The Sierra Club agrees with the Administrator of EPA that when the ozone standard is set the Clean Air Act requires that public health, with an adequate margin of safety, and not cost is the criteria that must be used to set the standard.
9) The Sierra Club supports having, in addition to the 8-hour ozone primary standard, a one-hour peak ozone primary standard that protects public health in areas affected by such high ozone one-hour spikes. The Houston Ship Channel and Texas City are areas where one-hour ozone spikes occur periodically and can affect nearby residents.
Approval of a NAAQS for ozone in the 0.060 ppm to 0.070 ppm range, 8-hours, will result in cleaner and healthier air for citizens all over Texas (about 16 million people) including those in Houston, Dallas, Fort Worth, Austin, San Antonio, El Paso, Corpus Christi, Victoria, and East Texas. This really is a matter of life and breath.
The Sierra Club appreciates this opportunity to comment. Thank you.
Air Quality Issue Chair
Lone Star Chapter of the Sierra Club
Chair, Air Quality Committee
Houston Regional Group of the Sierra Club
Houston, Texas 77096