Document kmjMZGQ1Q6Yb7NgxjgNQbQGYy

- CSOlVl '' January 10, 1968 KENNETH E. KEEPER ENO L 1285 I was pleased to hear from you yesterday that consideration is being given to monitoring the dust levels at 21 construction sites around the country at regular intervals. Z should like to suggest that some of these dust samples he examined for asbestos so that not only will the total count be known but also what fraction of the count is asbestos. A further point that is Important at the moment is the type of asbestos being used. Since there is some evidence (but certainly not enough for a dogmatic statement) that the type of asbestos may be Important in determining whether cancer is produced. At this time croeldollte is felt to be possibly more of a risk than ohrysotlle or amosltw. in line with this current feeling, Z am enclosing the tentative values being suggested by the A.C.O.X.H. for the H.V for Asbestos. The recommendation made is nothing but a proposal at this time but is indicative of the trend of industrial hygiene thinking. Unfortunately these tentative TLV'i are often taken as prlaa fade evidence by labor unions and state regulatory bodies. A further straw in the wind is a recent report on smoking amongst asbestos workers which indicates that the non-smoking asbestos worker has a slightly Increased chance of dying of chest disease compared with tha non-smoking non-asbestos worker but that the asbestos worker who smokes shows a much higher death rate due to respiratory disease than does the smoker who is not exposed to asbestos. In susnary, it seems essential to knowt 1 The dust exposure 2 The type of asbestos 3 The state of health of asbestos exposed workers at least at the de they are hired and at the time of discharge. Z have spoken to Jim Morgan about the matter of reading the dust counts, and we will be sending you a cost estimate in the near future. ORIOINAk SIONCO SV 11a o. J. STOWWS 0. J. Stopps, M.S.,B.S. Chief, Physiology Section OJS/pgh Enclosure DUP 0900917