Document kD0Bvpza5DZR7OeYpdv6RM8jq

- 16 - brought to the fore because sales of both are foreseen in the near future. Carbide's responsibilities are somewhat lessened, however, as the customers will mostly be firms already experienced in the use of asbestos, and those who are always under the watchful eye of the Factory Inspector. 6.2 Expected Rise in Asbestos Diseases In Figure 4, a diagram has been presented relating the history of the development of the asbestos industry and associated health hazards. It is seen that the world production has increased tremendously since the war. With the knowledge that mesothelial tumours can take up to 40 years to develop, it is expected that there will be a dramatic rise in the next two decades in the number of cases discovered. If this hypothesis is proved correct, then it is certain that asbestos will receive increasingly more adverse publicity. As a result, sales resistance to our product may be expected to strengthen. It is therefore imperative that we keep abreast of current research work and publications, in order that we may combat both informed and exaggerated criticisms. 6.3 Threshold Limit Value It is understood that the maximum dust level of 5 million particles per cubic foot (still adhered to by the U.K. Factory Inspectorate) was -proposed by an engineer in 1938 as an interim guide. This figure was an arbitrary choice, and had no experimental foundation. Dr. Taylor in his report of the International Conference on the Biological Effects of Asbestos, 1964, says: "The M.A.C. (Maximum Allowable Concentration) of 5 million particles per cubic foot is not now acceptable. Industry should aim at 1 million particles, and accept this figure with reservations until .ourknowledge in this field is extended." Dr. Taylor reiterated this again two days ago, but he did admit that practically 2 million particles per cubic foot might have to suffice for quite a while to come. It thus appears that the sentence in Dr. Demehl's Asbestos Toxicology Report: "It is now generally accepted that a man can work a 40-hour week for a lifetime without developing asbestosis, if the asbestos dust particle count is kept at or below 5 million particles per cubic foot of air." is now no longer held to be true by a number of informed people. An indication of the present opinion on this matter held by Union Carbide's Toxicology department would be most welcome. 6.4 Similarities Between Different Chrysotiles At the moment, there are signs that Chrysotile may be less responsible than Crocidolite for the development of mesothelial tumours. Should it be proven, either on statistical grounds or histochemieally, that this indication is indeed correct, then we must be certain that our material conforms closely ICS-017