Cancer risks in the optical manufacturing industry

Occupational exposures and colorectal cancers: A quantitative overview of epidemiological evidence

A traditional belief widespread across the biomedical community was that dietary habits and genetic predisposition were the basic factors causing colorectal cancer. In more recent times, however, a growing evidence has shown that other determinants can be very important in increasing (or reducing) incidence of this malignancy. The hypothesis that environmental and occupational risk factors are associated with colorectal cancer is gaining ground, and high risks of colorectal cancer have been reported among workers in some industrial branches. The aim of this study was to investigate the epidemiologic relationship between colorectal cancer and occupational exposures to several industrial activities, by means of a scientific literature review and meta-analysis. This work pointed out increased risks of colorectal cancer for labourers occupied in industries with a wide use of chemical compounds, such as leather (RR = 1.70, 95%CI: 1.24-2.34), basic metals (RR = 1.32, 95%CI: 1.07-1.65), plastic and rubber manufacturing (RR = 1.30, 95%CI: 0.98-1.71 and RR = 1.27, 95%CI: 0.92-1.76, respectively), besides workers in the sector of repair and installation of machinery exposed to asbestos (RR = 1.40, 95%CI: 1.07-1.84). Based on our results, the estimated crude excess risk fraction attributable to occupational exposure ranged from about 11% to about 15%. However, homogeneous pattern of association between colorectal cancer and industrial branches did not emerge from this review.

Autopsy cases of lung cancer and liver cancer among Japanese dentists--a review of the annual of the pathological autopsy cases in Japan

Dentists are exposed to carcinogenic metals during their work. It has been speculated that dentists are also at high risk for occupational exposure to bloodborne viruses such as hepatitis B and hepatitis C. We suspected that Japanese dentists were at increased risk for lung and liver cancer. To assess this question, we compared the number of pathological diagnoses of lung cancer and liver cancer among autopsy cases of male dentists (n=225) with that among autopsy cases of male medical doctors (n=1,296), based on data from the Annual of the Pathological Autopsy Cases in Japan from 1992 to 1999. We calculated the mortality odds ratio of lung cancer and liver cancer, using stomach cancer as the control. No difference between the dentist group and the medical doctor group was observed in the pathological diagnoses of lung cancer among all autopsy cases (p=0.703, Odds Ratio: 0.846, 95% confidence interval: 0.461-1.554). Liver cancer was observed less often among dentists than among medical doctors (p=0.047, Odds Ratio: 0.474, 95% confidence interval: 0.239-0.941). Based on the results of this study, we suggest that Japanese male dentists do not have a higher risk of developing lung cancer than male medical doctors, and have a lower risk of developing liver cancer.