Document LJKM4xM4VY8xk6dnap3wBy3KQ
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1 Q Now, when the TLVs -- I would like to ask
2 you about the history of the threshold limit values.
3 Did the ACGIH in 1946 create the TLV?
4 A No. Again, they create -- they recommend --
5 have a recommended value, but it is based on review of
6 the literature.
7 In the case of asbestos in 1946, it was
8 based on a 1938 study by Dr. Dreessen.
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9 Q Okay. Could you tell us, please, who Dr.
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10 Dreessen was and what his -- who he was and then I
11 will ask you what his study was about.
12 A Dr. Dreessen was a researcher in the U.S.
13 Public Health Service.
14 The U.S. Public Health Service existed at
15 that time , not as a regulatory body, but a body to do
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16 research.
17 Q And what did Dr. Dreessen do, and what did
18 he study and where?
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19 A Dr. Dreessen actually studied a number of
20 asbestos textile mills located in North Carolina. He
21 did what we call a cross-sectional study.
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