Wood dust links with sino-nasal cancer
The adverse effects of exposure to fine wood dust include respiratory allergic symptoms, mucosal and non-allergic respiratory symptoms, and cancer. However, the extent of these hazards and the particular wood responsible has not been clearly established. The EU-funded WOOD-RISK project therefore set out to collate up-to-date data on occupational exposure to wood dust. In particular, they investigated if there was any link between exposure and changes in genotype of cells in sino-nasal cancers. Project partners at the National Institute of Occupational Health in Copenhagen researched into a possible genetic basis for the effects of exposure to wood dust. Their first line of research was to study lung epithelial cells in vitro after exposure to seven types of wood dust including that obtained from both soft and hard woods. Potentially genotoxic effects were observed in four of the seven woods in the form of DNA strand breaks before inflammation reached its peak. An immune response was observed with all seven types of wood as production of cytokines. The same team also followed a line of research in sino-nasal cancers (SNCs). Previous studies had shown that the highest risk of cancer was evident in cells of glands (adenocarcinomas) from exposure to hardwoods. In particular, they looked for specific mutations in a certain oncogene, KRAS that had previously been observed in SNCs. The scientists looked at a collection of around 300 SNC tumours including adenocarcinomas. They looked for mutations in genes involved in cell division. KRAS produces a protein K-Ras that regulates cell proliferation. Another, p53 is also known as the genome guardian, with good reason. It prevents cells from growing in an uncontrolled way. They found that the incidence of mutations in KRAS was low. However, mutations in the tumour suppressor gene p53 were much more abundant - at variance with previous studies. Data from this research will provide a good basis for further analysis to unravel the effects of wood dust on molecular mechanisms, particularly genotoxic effects. Knowledge of concentration effects can be used to set tolerance limits to improve safety for the work force involved in wood and its products.
