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Mr. SYNAR. I will look for a little extra for your stocking this year 

 for your defense of EPA. Mr. Souby. I will tell Carol Browner you 

 were very good. 



I am not a scientist, nor is anyone on my staff, but I would like 

 to ask you a few questions regarding those charts you used, be- 

 cause that is an area of expertise that you have. I will also give 

 the Department of Interior scientists a chance to comment on your 

 data as part of their presentation. Did you look at any data before 

 1960? For example, I am told 1950 was a much better year to use 

 since it was a lot cleaner. 



Mr. Michaels. The CD-ROM unfortunately begins in 1960. 

 There are airport data available, a little bit more difficult to work 

 with 



Mr. Synar. Did you look at it- 



Mr. Michaels. Hold on. I looked at the literature. You do see de- 

 clines of visibility in the 1950's in the airport data. 



Mr. Synar. Did you look at it? 



Mr. Michaels. I looked at a paper by Dr. Sloan in which she 

 looked at it and commented that there are declines 



Mr. Synar. That is hearsay looking. 



Mr. Michaels. That is reading scientific literature. It is not 

 hearsay. She commented that much of the decline in the 1950's 

 could be attributed to some of the weather characteristics as well 

 as emission characteristics. 



Mr. Synar. Are sulfate trends consistent with visibility trends? 

 In other words, when sulfate went up, visibility went down? 



Mr. Michaels. They are partially consistent. That is the prob- 

 lem. 



Mr. Synar. The Parks Service says, yes. What do you say to 

 that? 



Mr. Michaels. I say that after the Clean Air Act of 1970, which 

 took time to take effect, that visibility appears to have improved 

 actually slightly before that took effect so one can't make a definite 

 statement on that. 



Mr. Synar. What do you think causes these visibility problems 

 at Shenandoah? 



Mr. Michaels. There are a lot of things. It is a very complicated 

 issue. It is not just emissions. It is weather. It is the land use char- 

 acteristics. We have a highly vegetative surface. It is a fact that 

 there is a natural background haze which is considerable. Conten- 

 tions that the — and I read in one person's testimony that the an- 

 nual mean visibility has dropped by — is only one-fifth of what it 

 was. That can hardly be the case because that would imply back- 

 ground visibility of about 100 miles. 



There is no heavily vegetative latitude that has that background 

 visibility. Those are very complicated issues. 



Mr. Synar. How much of the air quality problem is from out of 

 State? 



Mr. Michaels. I can't give you a hard number on that. 



Mr. Synar. Do you have any idea? 



Mr. Michaels. I would defer to my colleague in the Department 

 of Environmental Quality on that. 



Mr. Synar. How much of that is out of State? Identify yourself 

 for the record. 



