Malignant mesothelioma and asbestos exposure in Europe: Evidence of spatial clustering

Exposure to asbestos causes a wide range of diseases, such as asbestosis, malignant mesothelioma (MM) and other types of cancer. Many European countries have reduced production and use of asbestos and some have banned it altogether. Based on data derived from the World Health Organisation (WHO) Cancer Mortality Database, we investigated whether some regions in Europe could have a higher relative risk of MM incidence than others. The data were compared, including the number of MM deaths per million inhabitants and aged-standardized mortality rates. Applying Moran's I and Getis-Ord Gi statistic on the agedstandardized mortality rates of MM cases assisted the spatial analysis of the occurrence of health events leading to an assessment of the heterogeneity of distribution and cluster detection of MM. We found a statistically significant positive autocorrelation for the male population and also the general population, while there was no statistically significant positive one for the female population. Hotspots of relative risk of developing MM were found in northwestern Europe. For the general population, Great Britain and the Netherlands stood out with high levels at the 99% and 95% confidence levels, respectively. For the male population, the results were similar, but with addition of risk also in Belgium and Switzerland. However, in many European countries with high asbestos use per capita, the MM incidence was found to still be low. The reasons for this are not yet clear, but part of the problem is certainly due to incomplete data in registers and databases. The latency time can be longer than 40 years and is related to the intensity and time of exposure (occupational, para-occupational and environmental). In Europe, even though peak production occurred in the 1960s and 1970s, a significant decrease in production did not occur until 25 years later, which means that the impact will continue for as late as The mid 2030s.