ABSTRACT
OBJECTIVE: To compare and analyze the risk of formaldehyde hazards in a plywood manufacturing factory using two risk assessment methods,and to evaluate the occupational health risk. METHODS: Occupational health investigation and formaldehyde detection for workplaces were carried out in a plywood manufacturing factory in Shandong province. The risk ratings of different posts were assessed by US Environmental Protection Agency( EPA) inhalation risk( EPA assessment model) and Singapore Semi-quantitative Assessment Model( MOM assessment model). The risk classification results of the 2 risk assessment methods were compared and analyzed. RESULTS: The concentration of airborne formaldehyde on the positions of shaving,woods feeding,gluing,hot milling,hot pressing,sanding and reprocessing were 0. 25,0. 13,1. 47,0. 72,0. 92 and 0. 58 mg/m~3,respectively. By the EPA assessment model,all of the positions were evaluated as high carcinogenic risk. Through the MOM assessment model,the feeding position was evaluated as medium risk,the positions of shaving,hot milling,hot pressing sanding and reprocessing were high risk,and the position of gluing was higher risk. CONCLUSION: It suggests that there is a high formaldehyde exposure in several posts in the plywood production processing. EPA assessment model is a suitable for occupational health risk assessment for formaldehyde exposure.
ABSTRACT
Aim To investigate the protective effect of catechin on cerebral ischemia-reperfusion injury in rats and its mechanism.Methods 40 rats were randomly divided into 5 groups:sham operation group,model group and 50,100 and 200 mg·kg~(-1) catechin groups,with 8 rats in each group.The model of focal cerebral ischemia-reperfusion in rats was established with modified sutured-occluded method.The rats in catechin groups were injected with catechin at the matched concentration.The rats in sham operation group and model group were injected with saline.And all rats were given more time in 2 hours after ischemia.Rats were sacrificed for histologic examination after the behavioral test,and their brains were taken to assay the activities of MPO and NOS.Results Catechin at different dosages(50,100 and 200 mg·kg~(-1))could obviously decrease neurological deficit score,repair histological injury,and reduce the activities of MPO and NOS in rats of focal cerebral ischemia-reperfusion injury.Conclusions Catechin can relieve the cerebral ischemia reperfusion injury,and its mechanism may be partly related to the effects of its antiinflammation and antioxidation.