Asbestos Cement Materials
Asbestos cement workers have been exposed to chrysotile during the manufacturing process. One case of mesothelioma was found among 2363 chrysotile-only workers having 20 or more years of latency at a particular building (within Plant 2) in the New Orleans area. From 1927 until 1970, this man was continuously assigned to work in the shingle production area (chrysotile) only, according to his job record. However, the pipe production building was in the same plant where 7 cases of mesothelioma were diagnosed among 1231 subjects using crocidolite additionally (Hughes et al., 1987) and the locale was contaminated with plant asbestos waste (U.S. EPA Region 6 news release, 6/25/1998). At the Tamworth plant in England having 2167 workers in the cohort, 1 mesothelioma was reported, but the authors indicated that it was unlikely to be related to chrysotile because of the short latency in this case (Gardner et al., 1986) From Sweden, a cohort of 1176 workers having 27,000 person-years of follow-up did not have any mesothelioma cases. Although they represent less than 1 % of all asbestos, 400 tons of crocidolite and 630 tons of amosite were used in 1962 and between 1949 and 1951, respectively. A subcohort of 125 workers had average cumulative exposure of 18 f/ml-yr (Ohlson and Hogstedt, 1985).