CORDIS - EU research results

Studies aiming at assisting legislation and encouraging continual improvement strategies in the field of respirable crystalline silica (SILICERAM)

Final Report Summary - SILICERAM (Studies aiming at assisting legislation and encouraging continual improvement strategies in the field of respirable crystalline silica)

If a risk free environment cannot be delivered any reassurance from politicians and scientists that the level of risk is miniscule will not be believed, let alone accepted by many. A good deal of this is born from the misguided notion that science can and should deliver definitive answers all the time, whereas invariably the process and techniques used in science often only deliver the next set of questions, but in seeking answers to such questions the body of knowledge builds and progress is made.

This process is invaluable in tackling occupational health and has been the driving force behind the SILICERAM project, which has recently been completed. In a nutshell, the objective of the project was to pursue some of those unanswered questions which still plague our understanding surrounding the toxicology of respirable crystalline silica.

Silicosis is now a rare disease thanks to abatement measures adopted by the ceramics industry, one of a number of industries using Respirable crystalline silica (RCS), the cause of the disease. European legislators are considering the introduction of a new single lower limit for airborne RCS, despite the belief that various forms of RCS have different toxicities. In a the SILICERAM project, a 38-member consortium aimed to show that the proportion of dust capable of penetrating deep into the lungs, and the inherent toxicity, varies for different forms of RCS. Therefore, concessions should be made to ceramics producers according to the types of materials used and manufacturing conditions.

The whole debate relating to harmful effects of crystalline silica is very mature, in fact since the early 1900s occupational hygienists and physicians have known that prolonged and excessive exposure to RCS-containing dusts may cause silicosis, a particular form of pulmonary fibrosis leading to incapacity and premature death.

The project team showed that the probability of crystalline silica penetrating into the lung depends on the size of the particle. Large particles are exhaled anyway. Mathematical modelling revealed that only a fraction of the particle size distribution at a certain exposure level of RCS actually reaches the inner lung. The results will enable a revision of the exposures experienced by workers. Together with the toxicity data developed for different forms of RCS, concessions can then be proposed according to the types of material used and the manufacturing conditions.