(Jockel et al. 1998; Menvielle et al. 2003), transportation-equipment management (Menvielle et al. 2003), and shipyard work (Bovenzi et al. 1993; Hayes et al. 1989; Zahm et al. 1989).
The Dutch dietary cohort study (van Loon et al. 1997), from which exposure to ambient air pollution was estimated, was also used to estimate the incidence of occupational exposure to PAHs. Adjustment only for age showed that the RR of lung cancer increased by tertile of exposure. However, adjustment for age, smoking, and other occupational exposures led to risks that declined with increasing exposure. It is possible that the latter analysis, in which other occupational agents were included, was overmatched. An analysis adjusting for all potential confounding factors, excluding the occupational ones, was not conducted. A large census cohort study in Sweden that used a JEM to assign probability and intensity of exposure to diesel emissions on the basis of job titles collected in the 1960 and 1970 censuses showed that risks of lung cancer increased with the magnitude and probability of exposure among men but not among women (Boffetta et al. 2001). A study from the Kaiser Permanente Medical Care Program in California showed a 61% excess of lung cancer among bus-garage mechanics and showed that RRs increased by an index of cumulative diesel exhaust (Van Den Eeden and Friedman 1993).
Male firefighters in Philadelphia did not appear to be at increased risk for death from lung cancer when a surrogate index of exposure to diesel exhaust was used, although the power of the study was likely to be low because of small numbers of cases and a surrogate index of exposure (Baris et al. 2001). In a cohort of US railroad workers, younger diesel-exposed workers were found to be at higher risk, presumably because the younger workers had the greatest duration of exposure (Garshick et al. 1987, 1988; Larkin et al. 2000). Potash miners in Germany were at higher RR for death, but the 95% CIs included the null (Saverin et al. 1999). Risk was found to increase with cumulative exposure to diesel among a cohort of bus garage mechanics in Stockholm (Gustavsson et al. 1990). In the ACS CPS II study, it was reported that risk increased with duration of self-reported exposure to diesel exhaust (Boffetta et al. 1988); a limitation of this analysis is the use of self-reported exposure.
Risk estimates associated with exposure to specific components of exhaust have come out of a number of studies. Increased lung-cancer risk with cumulative exposure to diesel exhaust and to PAHs from occupational sources was found in a previously cited case-control study in Germany (Bruske-Hohlfeld et al. 2000) and in a study in Stockholm (Gustavsson et al. 2000). However, exposure to diesel exhaust from occupational sources was not found to increase the risk of lung cancer in a US hospital-based case-control study (Boffetta et al. 1990) and exposure to PAHs was not found to increase the risk in occupational studies in Buenos Aires (Matos et al. 2000), Montreal (Nadon et al. 1995), and Sweden (Emmelin et al. 1993).
Many studies have assessed the association of indoor air quality related to types of heating or cooking fuels, such as coal, with lung cancer. Studies of exposure to heating or cooking fuels included a number from China (Alarie et al. 1972; Dai et al. 1996; Du et al. 1996; He et al. 1991; Huang et al. 1992; Kleinerman et al. 2002; Lan et al. 1993; Lei et al. 1996; Liu et al. 1993; Metayer et al. 2002; Shen et al. 1996; Wu-Williams et al. 1990a, 1993; Xu et al. 1989, 1996a; Zhong et al. 1999), Hong Kong (Koo et al. 1983) and Taiwan (Chen et al. 1990; Ko et al. 1997), many of which showed such associations. Only one cohort study investigated the effects of indoor air pollution on the risk of developing lung cancer (Lan et al. 2002). That population-based interview study included more than 31,000 farmers living in Xuanwei, China, who were followed from 1976 to 1992. The analysis was based on subjects whose parents used unvented firepits and smoky coal throughout their lives. It showed that changing to stoves that had