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Dr. James Ultman <br />Comments on the Final Draft of the Ozone Staff Paper <br />James Ultman <br />March 13, 2007 <br />The staff is to be congratulated on producing a fmal document that is well-written and contains a <br />logical risk analysis based on clearly justified health end points. <br />I strongly agree with staff s conclusion (3) on page 6-86 that the current scientific evidence <br />provides strong support for consideration of a standard that would provide increased public <br />health protection. <br />I disagree with staffs recommendation (3)(a) that consideration be given to a standard in the <br />range of "somewhat below" 0.08 to 0.06. The phrase "somewhat below" is nebulous and allows <br />the possibility of a standard that is "somewhat below" and yet essentially equivalent to the <br />present standard of 0.08 ppm. I believe that there is sufficient scientific evidence, particularly <br />with respect to hospital admissions and lung function decrements, to change the level of the <br />standard to 0.07 ppm or lower. <br />The present staff paper is not adequately informed by scientific studies regarding the synergistic <br />effects of other air pollutants in smog on the effects of ozone. As a result, staff had little choice <br />but to conclude that ozone alone can still be considered an indicator of effects that occur in the <br />presence of other photochemical oxidants (Conclusion (1) on page 6-85). There are also <br />inadequate research results concerning the amplification ofozone-induced effects during lung <br />development, a process that most likely is affected by ozone level as well as the time-history of <br />exposure. It is imperative that research in these two orphaned areas be stimulated by the EPA. <br />Laboratory studies of compromised lung function at exposures below 0.08 ppm played an <br />important role in staff s recommendation to lower the ozone standard, and yet, the available data <br />is limited to small populations (see table 5.3). Clearly, additional measurements of this type are <br />a high priority before the next review cycle of the ozone standard begins. <br />C-29 <br />