This experiment chose the wood processing environment to conduct bacterial strain identification and endotoxin exposure investigations.The experiment used the single-stage and six-stage Anderson samplers, Biosampler, AGI-30 and SKC aluminum cyclone with PC filter paper to evaluate the concentration of the bacteria and respirable wood dust in the wood processing plant.

The results show that the dominant strains identified from the bacteria sampled at the plant were Bacillus spp. and staphylococcus spp. Among these, the majority were gram-positive bacteria, whose dominant strain was Bacillus spp.. The bacteria concentration in the cutting area was greater than that in the logging area, which should be related to the flying of wood dust during the cutting. The statistical results indicated that gram-positive bacteria differ significantly from the bioaerosol sampler types (P= 0.0002). They were also significantly different from the concentration of gram-negative bacteria in terms of temperature and humidity (P<0.05). Regarding the biological safety level (BSL) classification, the class II bacterial bioaerosol accounted for 51.7%. In the working environment, all bioaerosol samplers showed that the endotoxin content detected in Pantoea agglomerans (cultured) was much higher, being 0.8053 EU/m³. The total endotoxin concentration range collected by SKC cyclone separator with PC filter paper was 2.1639×10-6~5.1850×10-6 EU/m³. At present, there are no complete standards on the content limit of respirable wood dust concentration and the exposure limit of endotoxin in the working environment. Standards are recommended to be imposed in the future to prevent the increase of occupational exposure.