(CASAC) Peer Review of EPA's Integrated Science Assessment

p. 3-11; ll. 7-18: Another reason for the similarity in response between mild andmoderate/severe asthmatics is that the latter were not able to exercise as intensely as themild asthmatics. It should also be noted that studies (e.g., Gong et al., 1996; Gong et al/.2001; Linn et al. 1988) have shown that medicated asthmatics were not sensitive to SO2exposure.p. 3-15, ll. 11: insert “exercising, non-medicated” before asthmatics.P. 3-16, l. 3: Linn et al., 1983 reported a significantly increased response amongasthmatic subjects utilizing a mouthpiece for exposure as opposed to those withunencumbered breathing. This reference can be cited here.p. 3-35, l. 10: “statistically”p. 3-43, ll. 10-19: Systematic examinations of the potential influence of co-pollutants onstudy results are rare. Studies often consider a limited set of co-pollutant with nodiscussion about why other co-pollutants are not considered. It would be useful toindicate the need for more systematic review of this issue within a study.p. 3-45, ll. 1-7: It should be noted that the panel studies found responses at ambientlevels only when asthmatics were exercising.p. 3-46, l. 31: reference should be given.p. 3-47, ll. 14-20: It should be noted that exposure was by mouthpiece. See comments forp. 3-16.p. 3-49, ll. 16 and following: It should be noted that the exposure levels in the studiescited in this section were extraordinarily high. This comment applies to section 3.15.2.5.p. 3.55, ll. 21-22: It should be noted that controlled human studies did not findresponses in adult atopics. (Linn et al., 1987).p. 4-2, l. 1: Measurement error can also serve to linearize dose-response estimates.p. 4.4, ll. 10-11. See comment for page 4-2.p. 4-11, ll. 4-13: It might also be noteworthy to indicate that asthmatics on routinemedication do not appear to respond to SO2 while exercising.54