Document QXn87eqXe7X2Kyyy8b3MwZLw6

Mr. L. V. Thatcher - 3/27/68 greater than 5 U per ee If possible and' certainly below 10. I would strongly recommend that you keep asbestos exposure as low as possible until we have better information on its toxicity, not only for asbestosis but also for lung cancer. Please let me know if Z can provide ary additional information. Sincerely yours. Enclosure Asst. Chief, Snviromental Activities Field Studies Occupational Health Program DUP 0900961 129647