The previously valid General Limit Value for Particulate Matter derived by the Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area of the German Research Foundation (DFG), most recently updated in 1997, was intended to prevent chronic bronchitis and chronic obstructive pulmonary disease. Since compliance with it permitted an e5% increase in the basic prevalence of these diseases among employees, it entailed a residual risk of particle-induced disease and failed to comply with the definition of a MAK (German maximum workplace concentration) value. The Senate Commission therefore thoroughly revised the General Limit Value for Particulate Matter in 2011. It also had to take account of the fact that the findings of animal experiments had demonstrated the carcinogenicity of biopersistent dusts without a specific toxic effect. The evaluation of the scientific literature revealed that this carcinogenicity is attributable not to a primary genotoxic mechanism but to indirect damage to the DNA due to reactive oxygen species formed by macrophages and leukocytes during inflammation processes when the clearance mechanisms of the respiratory passages and lungs are overwhelmed. The new General Limit Value for Particulate Matter for the respirable fraction is intended to prevent inflammation due to impaired clearance mechanisms and hence exclude an elevated risk of lung cancer, pulmonary fibrosis, and chronic inflammatory disease due to particulate matter of low toxicity.
Author: Hallier, E. ;Full Source: Gefahrstoffe Reinhaltung der Luft 2011, 71(10), 415-418 (Germany) ;