Cancer mortality and exposure to chemical carcinogens in the work place: An ecological study in the Valencian Community, Spain (1981-1995)

To evaluate the geographical distribution of the mortality from malignant t umours in relationship with exposure to chemical carcinogens in the work pl ace, and to asses the possible association between these questions and the percentage of population employed in certain high-risk sectors, an ecologic al study in the Valencian Community (VC), Spain was carried out. Age-adjust ed mortality rates for the total number of malignant tumours, lung, bladder , lymphomas and leukaemia during the periods 1981-1985 and 1991-1995 were c alculated for the 34 geographical areas. The percentage of population in ea ch area working in sectors in which they may be exposed to chemical carcino gens was obtained. The relationship between mortality on-the-job exposure w as studied using linear regression methods. Large differences in cancer mor tality were seen. In men, the geographical pattern was very stable and reve als a significant association with the distribution of certain high-risk jo bs. cStatistically significant positive correlations (p < 0.001) were found between cancer mortality and the percentage of the population working in m etal, wood and furniture sectors. In contrast, a negative and statistically significant (p < 0.001) correlation was observed between cancer mortality and the percentage of the population working in agriculture. In conclusion, although the variability in cancer mortality in men was significantly asso ciated with some occupational sectors in the VC, caution is needed when dra wing conclusions about causation from ecological studies.