Review of the Air Quality Criteria Document for Particulate Matter

% deposition, more than 7 months would be needed to deposit 5 mg of the ironoxide particles in the lung since only about 20 mg would be deposited in a day).p. 8-16 The concentration stated in the table for the Madden et al. study should be 1000mg in 0.5 ml.p. 8-17 For the Watkinson et al. study, what were the nose-only inhalationconcentrations?p. 8-18, Table 8-5 Given the low exposure of 10 mg/m 3 for 4 hours in the Ohtsuka et al. study,this paper warrants expanded discussion in the text.p. 8-24 The symbol for the geometric standard deviation is not as it appears in the tablebut rather should be the Greek symbol s. The same statement can be made forTable 8-7.p. 8-28, Table 8-7 This reviewer finds it of great interest that intertracheal instillation of ROFA inthe Watkinson et al. study showed effects but inhalation of 15 mg/m 3 six hoursper day for three days of the same compound showed no effects.p. 8-29, l. 11 20 In the Killingsworth et al. Studies using monocrotaline-MCT, mortality andchanges in MIP-2 were noted. What human condition does this model mimic?p. 8-32, l. 6 19 This paragraph comes across as if the Godleski et al. HEI Report is consideredpeer reviewed and the study by Muggenberg et al. appearing in an InhalationToxicology Supplement from the PM 2000 Meeting is not peer reviewed. Thefact that these studies differed in their findings is what should be emphasizedbecause Godleski used concentrated ambient particles and Muggenberg usedhigh concentrations of ROFA. If EPA has criteria for what the agency considerspeer reviewed versus not peer reviewed, these criteria should be so stated andapplied uniformly throughout the Criteria Document.p. 8-31, l. 18 19 The statement is made that the different findings between the dog studiesillustrate the difficulties in extrapolating animal toxicological data to humanhealth effects. The sentence falls short in that it fails to note that lack ofunderstanding of mechanism of action is the primary problem withextrapolating animal results that are disparate in nature to humans.p. 8-33, l. 6 9 The results from the Gordon et al. study are interpreted in this paragraph tosuggest that day-to-day changes in particle composition may play an importantrole in the systemic effects of inhaled particles. This is an overinterpretation ofp. 8 34, l. 4 14 In addition to the potential mechanisms discussed in this paragraph, the role ofendothelins should be mentioned. Vincent et al. (Inhalation Toxicology ofAmbient Particulate Matter: Acute Cardiovascular Effects of ResuspendedEHC-93 Urban Particles in Wistar Rats. Final Report to the Health EffectsInstitute for the Collaborative Study 98-32, In Press, 2001) have shown thatparticles can affect endothelin 1 and 3 more than 30 hours post exposure.p. 8-37, l.10 Replace the word although with the word after.p. 8-41, l. 18 Broad statements such as what Nell et al. made in their article on suggestingthat the rise in the U.S. prevalence rate for allergic rhinitis may be related toincreased diesel emissions in addition to other combustion sources is highlyspeculative. Anyone can suggest a material is the culpritive agent for an effectbut the emphasis in a criteria document ought to be on the proof for suchrelationships based upon experimental data.p. 8-46, l. 13 The astronomically high carbon black exposure level used by Jakab producedno effect on susceptibility to bacterial infection in contrast to high exposurestudies with titanium dioxide. Comparing such results implies that a particle isnot a particle and that composition or the nature of the particle is important forthe effects on the host. The Criteria Document does not put as much emphasison pointing out concepts such as this as what might be appropriate.p. 8-61, l. 3 Round 11.9-fold to 12-fold. Such rounding is undoubtedly more in accord withthe accuracy of the data.p. 8-62, l. 3 The concept discussed here that a combination of several components ratherthan a single metal in PM is likely responsible for cellular effects is worthbringing forward as one of the major conclusions that can be gained fromexamining the toxicological data on PM.p. 8-67, l. 4 The Lee et al. studies described here involved sulfuric acid aerosolconcentrations so high as to make the results of little value to the discussion ofA - 9