Document 3NMyqXpKjBa9NEaNQ1Xb3Gq3a

1 1. INTRODUCTION Asbestos is a general name given to a variety of useful fibrous minerals. The value of asbestos ensues from the indestructible nature of products fabricated from the various grades of mineral fibers. The major asbestos minerals are chrysotile, crocidolite, amosite, and anthophyllite,. while tremolite and actinolite are considerably less important. Over 90 percent of the asbestos is chrysotile. The United States uses about one-fourth of the world production of this substance, practically all imported from Canada and Africa. Inhalation of asbestos dust has long been recognised as 161,165 an industrial hazard. Early in this century, exposure to high concentrations of the fibrous dust was causally associated with a6bestosis. In 1935, evidence began to accumulate that cancer of the lung is also associated with inhalation of asbestos.^5 More recently, certain rare cancers, pleural mesotheliomas and peritoneal mesotheliomas, have been associated with inhalation of asbestos fibers by asbestos workers. 176 Heimann92 states that "The finding of several such rare tumors in any given group makes that group suspect of having special and distinct environmental characteristics, in this case, exposure to asbestos duBt." Nonoccupational environmental exposure to asbestos was D1 found as early as 1927 vfaen Haddow reported finding so- called "asbestos bodies" in the lungs of a person living near 8000 lRlR PRODUCED BY FORD