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Background Existing methods to estimate lifetime exposure to occupational carcinogenic agents could be improved. Objective We propose a new method to estimate the lifetime prevalence of exposure to occupational carcinogens using the example of painters and workers of the rubber industry in France. Methods From census, we calculated the proportion of painters and rubber industry workers using predefined occupational codes related to each occupation by sex and 10-year age group in 1982, 1990, 1999, 2007, and 2013. Using a beta-regression model, we obtained the yearly prevalence of exposure by 10-year age group over the period 1967-2007. We estimated the age- and sex-specific lifetime prevalence of exposure of the population in 2017 over 1967-2007, summing up the estimated prevalence of exposure for years 1967, 1977, 1987, 1997, and 2007 combined with a sex- and age-specific turnover factor. Corresponding population-attributable fractions were estimated for lung and bladder cancers in 2017. Results In 2017, we estimated that 5.6 and 0.2% of men in France had ever worked as a painter or in the rubber industry, respectively, during their working time. The lifetime prevalence of ever having worked as a painter or in the rubber industry was much lower in women: 1.8% and 0.1%, respectively. We estimated that 950 lung cancer and 40 bladder cancer cases were attributable to these occupations in 2017. Significance Based on accurate data and taking into account evolution of specific jobs over time, the proposed method provides good estimates of lifetime prevalence of exposure to occupational carcinogens. It could be applied in any other country with similar data.

Background Many epidemiological studies have reported the association between exposure to particulate matter and mortality, but long-term prospective studies from Asian populations are sparse. Furthermore, associations at low levels of air pollution are not well clarified. Here, we evaluated associations between long-term exposure to particulate matter 3 (PM2.5) and mortality in a Japanese cohort with a relatively low exposure level. Methods The Japan Public Health Center-based Prospective Study (JPHC Study) is a prospective cohort study of men and women aged 40-69 years in 1990 who were followed up through 2013 for mortality. In this cohort of 87,385 subjects who did not move residence during follow-up, average PM2.5 levels from 1998 to 2013 by linkage with 1-km2 grids of PM2.5 concentration were assigned to the residential addresses of all participants. To avoid exposure misclassification, we additionally evaluated the association between 5-year (1998-2002) cumulative exposure level and mortality during the follow-up period from 2003 to 2013 in 79,078 subjects. Cox proportional hazards models were used to calculate the association of long-term exposure to PM2.5 on mortality, with adjustment for several individual confounding factors. Results Average PM2.5 was 11.6 µg/m3. Average PM2.5 exposure was not associated with all-cause mortality or cancer and respiratory disease mortality. However, average PM2.5 was positively associated with mortality from cardiovascular disease (hazard ratio (HR) of 1.23 (95%CI=1.08-1.40) per 1-µg/m3 increase; in particular, HR in mortality from cerebrovascular disease was 1.34 (95%CI=1.11-1.61) per 1-µg/m3 increase. Additionally, these results using cumulative 5-year PM2.5 data were similar to those using average PM2.5 over 15 years. Conclusions We found evidence for a positive association between PM2.5 exposure and mortality from cardiovascular disease in a Japanese population, even in an area with relatively low-level air pollution.

The association of fermented soy products, separately from total soy products, with cardiovascular disease (CVD) and total cancer has not been reported. We examined this association in a population-based prospective cohort study in Japan. We studied 79,648 participants (42,788 women; 36,860 men) aged 45–74 years without a history of cancer, myocardial infarction, or stroke. Participants completed a food frequency questionnaire (1995–1998) and were followed to 2009–2012. Cox proportional hazards regression analysis was used to calculate the hazard ratios (HR) and 95% confidence intervals (CI) of incidence of CVD and total cancer according to quartiles of total soy products, nonfermented soy products, fermented soy products, miso soup, natto, total isoflavones from soy products, isoflavones from nonfermented soy products, and isoflavones from fermented soy products. In women, we observed a significant inverse association between fermented soy product intake and the risk of CVD (multivariate HR in the highest compared with the lowest quartile of fermented soy product intake: 0.80; 95% CI: 0.68, 0.95; P for trend = 0.010), and also found significant inverse associations for natto and isoflavones among fermented soy products. In site-specific analysis, we observed a similar, significant inverse association between fermented soy product intake and the risk of stroke in women. We found no significant association between any soy product and risk of CVD in men or total cancer in both sexes. Intake of fermented soy products such as natto was inversely associated with the risk of CVD in women.