Article Text
Abstract
Objectives: Genotoxic risks resulting from exposures to airborne particulates might still be present in the contemporary rubber industry. Therefore, trends in levels of inhalable dust and its cyclohexane soluble fraction (CSF) between the 1970's and 2003 in the rubber European rubber are important to assess. Methods: 13,380 inhalable and 816 respirable dust, as well as 5,657 CSF measurements, were collected within the framework of the European Union Concerted Action EXASRUB, and were used in these analyses. Hierarchical mixed effects models were applied to assess exposure trends, taking into account between factory, between worker/location, and day-to-day variances. Results: Geometric mean levels of inhalable dust and CSF exposure changed by -4% (range -5.8 to +2.9%) per year and -3% (range -8.6 to 0%) per year. Significant reductions in inhalable dust concentrations were found in all countries for handling of crude materials and mixing and milling (-7%/yr to -4%/yr), as well as for miscellaneous workers (-11%/yr to -5%/yr), while significant CSF exposure reductions were found in curing (-8.6%/yr), and maintenance and engineering departments (-5.4%/yr). Conclusion: These analyses suggest that on average exposure levels of inhalable dust and its cyclohexane-soluble fraction in the European rubber manufacturing industry have steadily declined. Most likely genotoxic risks have decreased over time since exposure levels have decreased and the most toxic chemicals have been replaced. In addition to differences in exposure reductions and levels among various stages of the production process, large differences across countries were noted. These patterns should be taken into account in retrospective assessment of exposure for epidemiological studies assessing cancer risk in the rubber industry.
- CSF
- cyclohexane soluble fraction
- inhalable dust
- rubber industry
- timetrends