Review of the Air Quality Criteria Document for Particulate Matter

More documents

Recommendations

Info

substantial uncertainty in the organic carbon measurements. I do not remember whether thisissue was addressed in this chapter. If not, this is an important topic that should be discussedextensively. These inherent organic carbon measurement uncertainties may make it moredifficult to reach particle mass closure.This chapter would be better if the discussion about carbon was a little more concise. Incontrast, the discussion on the elemental analysis, pages 77-80 is only rudimentary. If theauthors do not want to give many details about the methods, this is fine, but at least they shoulddiscuss the advantages and shortcomings of these methods. A more critical discussion isappropriate because elemental tracers are of paramount importance to source apportionmentstudies. The problem (which is good news from the health effects perspective) is that traceelement concentrations have decreased and XRF may not be the most adequate method, althoughis the most practical one. Reading this section one cannot find a take-home message about thestate-of-science in this area.Below are some minor specific comments:Section 2.2.1.5; It may be worthwhile to report some results from the compliance network. Iknow OAQPS has results from the FRM audits. I think it is important to mention somethingabout the precision of the FRM sampler under real ambient conditions as operated throughoutthe country by different states.Page 2-64, lines 7-8; I am not sure if this statement is correct.Page 2-73, line 10; Particle/particle interactions also are very important. For example, thereaction between ammonium nitrate and sulfuric acid or other acid sulfate particles can result inthe formation of nitric acid vapor that can be lost from the filter. Of course, it is notthermodynamically possible that ammonium nitrate coexists with acid sulfates in theatmosphere. However, during the collection of a multi-hour sample, e.g. 24 hours, thesecompounds can be present in the atmosphere at different times and thus can be collected on thesame collection mediumSection 2.2.5; There was in inter-comparison study of continuous methods supported by CARBin Bakersfield. Some of the findings from this study should be presented here, since this is oneof the most comprehensive continuous particle methods inter-comparison studies.Page 2-91, line 22-until the end of the sections; Too many details are presented here and I do notunderstand the point being made.Page 2-94; A section on continuous sulfate measurements should be included. Discuss the oldFID method and the new Fluorescence method which will be used by most of the supersites (byAllen et al, Harvard University).Page 2-97; The discussions on data quality is very superficial and incomplete. I suggest to fix itor drop it.Page 2-102, lines 24-26; Need to eliminate. The authors have been made a big deal of thisthroughout the chapter.Page 2-105, lines 4-5; This sentence does not mean anything, therefore I suggest to eliminate it.Chapter 3: Concentration, Sources, and Emissions of Atmospheric Particulate MatterThe revised chapter has been considerably improved. The authors considered most of ourprevious comments. They have used more recent information and have expanded the scope ofA - 53
the chapter. Many of the poor quality figures have now been replaced. The addition of theappendices has strengthened the chapter. I really enjoyed reading them. Although they werelong, I found them very informative and am sure many people will use this information.The summary section needs some improvement. It should be more comprehensive and contain agood synthesis of the presented information. It does not read like a good summary, rather it onlypresents some highlights of chapter 3. The summary section should include a concludingparagraph on the background concentrations. In the main text the authors presented a nicediscussion on this topic, but it was not clear what was the bottom line on this issue. Therefore,one would also expect some mention of this in the summary.The weakest part of the chapter is the discussion about emissions and their trends. I know this isa very difficult topic and the existing information is very limited. For this reason the NRCcommittee on particle research has recommended that EPA investigates particle source emissionin a comprehensive manner. The chapter does not acknowledge this lack of information, ratherit tries to make a good story which is not there. The introduction of the emission section isconfusing and the discussion on uncertainties is rudimentary. Some discussion on methods tomeasure emissions may be worthwhile to include. Also some discussion about the importance ofbiogenic sources would be worth including.Below are some minor specific comments:Table 3-1; Do the percent contributions correspond to sulfate and nitrate or to ammonium nitrateand ammonium sulfate?Figure 3-1; This figure is not clear. It is hard to distinguish the solid circles. Same for Figures3-4a and 3-4b. It is really hard to read these figures.Figure 3-2; How were the nationwide trends calculated? Were the lines in the figure interpolatedbetween the two successive years or are they moving averages?Page 3-10, line 7; ..acids. Define which acids.Page 3-10, lines 24-27; This sentence is not clear.Page 3-12, lines 6-8; This sentence is not clear, needs editing.Table 3-8; These studies should be sorted: alphabetically, chronologically, or geographically.Page 3-49, section 3-4; This section is not well written. What is the message here? This sectionis confusing.Figure 3-23; The title of figure should read “PM2.5 Total Primary Emissions....”. It should beclear that this table presents only primary emissions.Page 3-53; In lines 21-24 you mentioned that sulfate concentrations decreased less than thecorresponding sulfur dioxide (I agree with this statement). However, in Table 3-10 sulfatedecrease is 39% and sulfur dioxide is 16%. Something is wrong here?Table 3A-1; This is a very useful table. It would be nice (if it can be done easily) to include theOC/EC ratios for the different sites.Page 3B-1; In the first three lines you use three times the word “discuss/discussions”.Page 3B-24, line 19; Use = instead of - for sulfate.A - 54
Page 5:
known, the potential causes deserve
Page 10:
SCIENCE ADVISORY BOARD STAFFMr. A.
Page 13 and 14: Page 2-77, line 19-22: Should menti
Page 15 and 16: Page 8-1, lines 26-28: Combustion a
Page 17 and 18: mode vs. the other. In fact, such k
Page 19 and 20: p. 7-49, l. 20 In an effort to make
Page 21 and 22: ambient PM effects. The paragraph d
Page 23 and 24: dominant, one criticism is that “
Page 25 and 26: 6. Susceptible sub-populationsIt is
Page 27 and 28: is OK. But in most settings it stil
Page 29 and 30: 2. There are repetitions of the sam
Page 31 and 32: 15. Page 3-57 and 3-58, line 29-31
Page 33 and 34: P 7- 27, L 15: What does “compara
Page 35 and 36: there is pertains almost solely to
Page 37 and 38: studies, and is presented as observ
Page 39 and 40: P 8-47, L 23-27: These two sentence
Page 41 and 42: also be summarized. Second, the cha
Page 43 and 44: P 9-76, L 30: It should be “these
Page 45 and 46: 4. Page 4-7,lines 14-18. Similar th
Page 47 and 48: control when it may be possible to
Page 49 and 50: 1990. Reference Lioy, P.J. “The A
Page 51 and 52: document.P. 5-82, Lines 15-30 Need
Page 53 and 54: 7-12 8 insert "that are either very
Page 55 and 56: 8-62 10,11 The preceding discussion
Page 57 and 58: 9-27 17 insert "source and/or" afte
Page 59 and 60: 2. The paper by Künzli et al. on t
Page 61 and 62: 6-243 12 This section (6.4.4.) shou
Page 63: Chapter 5. Human Exposure to PM and
Page 67 and 68: Page 5-17, equation 5-10; the coeff
Page 69 and 70: illustrated using a figure from Kel
Page 71 and 72: tied back to the base-line health s
Page 73 and 74: Page 7-4, Structure of the Respirat
Page 75 and 76: Günter Oberdörster, PhDChapter 7
Page 77 and 78: efficiencies as well as the ratio o
Page 79 and 80: The title of this section is also s
Page 81 and 82: old and young rats and mice used on
Page 83 and 84: passive use values as opposed to us
Page 85 and 86: Specific Comments:Page 5-19, lines
Page 87 and 88: Chapter 9 - General CommentsThis ch
Page 89 and 90: George Taylor, PhDAir Quality Crite
Page 91 and 92: atmospheric stressors associated wi
Page 93 and 94: “At the surface, a variable fract
Page 95 and 96: that point from this review! “Vis
Page 97 and 98: 6. P 2-86, section 2.2.5.1 - A shor
show all

Review of the Air Quality Criteria Document for Particulate Matter

Create successful ePaper yourself

Delete template?

Save as template?