Occupational exposure to cement dusts and cancer risks: a literature review

Introduction : Cement is widely used both by the general public and in industry. Allergic pathologies related to long-term use of cement are well-known. Other pathologies, namely respiratory pathologies (asthma, lung-function decrease...) are also mentioned in relation to exposure to cement. Moreover, doubts have been expressed concerning its possible role in cancer. Because of the large number of exposed persons we undertook the present literature review concerning the incidence of cancer and the corresponding mortality related to the exposure to cement dusts. Two activities were thus selected : the cement production on one hand and its use among masons on the other hand.
Methods : A literature search in PubMed was performed in November 2001 with keywords " cement " and " masons ". Among the retrieved references, as well as from their corresponding references, 25 papers were selected.
Results : Among the studies concerning cement plant workers, no evidence of a lung cancer risk was found. The possible risk of digestive cancers, if it exists, is small and concerns cancers of the lower digestive tract (relative risks from 1.15 to 1.68). Among masons, all studies relate a statistically significantly elevated lung cancer risk (relative risks from 1.20 to 6.25) and an increased risk of cancer of the larynx which is statistically significant in three studies. Moreover, some studies mention an increased risk for stomach cancer (relative risks from 1.00 to 2.08).
Discussion : This literature review was focused on cancer risks in relation to cement dust exposure among two types of populations : cement-plant workers and masons. Some authors argue that the increased lung cancer and larynx cancer found among masons are not attributable to smoking. However, given the concomitant exposures to other occupational carcinogens (quartz and asbestos), it is difficult to conclude as to a ethiology by cement dusts.
Conclusion: Given the co-exposure to other carcinogens, the observed excess cancer risks for lung, larynx and digestive tract, cannot be specifically attributed to the exposure to cement dusts : the results are too heterogeneous to conclude as to a causal relationship