Objective: To understand the current status of dust and/or harmful gas exposure in adults aged ≥40 years and corresponding protection in China, and provide evidence for strengthening the occupational protection against dust and harmful gas exposure. Methods: The data were obtained from 2014-2015 COPD surveillance in China. A total of 75 107 adults aged ≥40 years selected through multi-stage stratified cluster sampling from 125 surveillance points in 31 provinces (autonomous regions and municipalities) were surveyed in face to face interviews. Occupational exposure was defined as occupational exposure to dust and/or harmful gas for more than 1 year. The weighted percentages of exposure were estimated by using complex sampling design. Results: Among eligible 71 061 participants, the exposure rate of dust and/or harmful gas was 46.3%. The exposure rate in rural area (51.7%) was significantly higher than that in urban area (40.3%), and the exposure rate in the western area was higher than those in the eastern and central areas (P<0.001). Among the groups with different education level, the exposure rate in those with education level of primary school and below was highest (49.7%, P<0.001). The exposure protection rate was 26.7%, and the exposure protection rate was highest in the eastern area (29.9%), followed by that in the central area (27.0%) and that in the western area (22.9%) The exposure protection rate in urban area was significantly higher than that in rural area, and the exposure protection rate was lowest in those with education level of primary school and below. The regular exposure protection was taken by only 50.7% of the adults surveyed. Conclusion: The exposure rate of dust and/or harmful gas is high in China, while the exposure protection rate is very low. Health education, occupational protection and supervision should be strengthened among those with low education level, and those living in rural area and in the western area.
Adult ; China/epidemiology* ; Dust ; Female ; Gases/toxicity* ; Humans ; Male ; Middle Aged ; Occupational Diseases/epidemiology* ; Occupational Exposure/statistics & numerical data* ; Residence Characteristics ; Rural Population ; Surveys and Questionnaires ; Urban Population

OBJECTIVES: We established a Wistar rat model of asthma caused by toluene diisocyanate (TDI) exposure, and investigated the relationship between TDI exposure concentrations and respiratory hypersensitivity, airway inflammation, and cytokine secretions in animals, to better understand the mechanism of TDI induced occupational asthma. METHODS: Wistar rats were exposed to two different concentrations of TDI vapor four hours a day for five consecutive days. Bronchoalveolar lavage (BAL) was performed, and differential leucocytes from the BAL fluid were analyzed. Lung histopathological examination was carried out to investigate the inflammatory status in the airways. Production of cytokines interleukin (IL)-4 and IL-5 productions in the BAL fluid in vivo was determined with enzyme-linked immunosorbent assay kits. RESULTS: The TDI-exposed rats exhibited greater airway hypersensitivity symptoms than the control rats. The BAL differential cell count and lung histopathological examination demonstrated that inflammation reactions were present in both the central and peripheral airways, characterized with marked infiltration of eosinophils in the TDI-exposed rats. The cytokine assay showed that IL-4 and IL-5 were predominantly produced in the BAL fluid in vivo. CONCLUSIONS: These findings imply that TDI exposure concentrations may greatly affect the occurrence and extent of inflammatory events and that Th2 type cytokines may play an important role in the immunopathogenesis of TDI-induced occupational respiratory hypersensitivity.
Animals ; Bronchoalveolar Lavage Fluid/chemistry/cytology ; Enzyme-Linked Immunosorbent Assay ; Eosinophils/cytology/immunology ; Female ; Gases/chemistry ; Hypersensitivity/pathology ; Interleukin-4/*analysis ; Interleukin-5/*analysis ; Lung/*drug effects/pathology/secretion ; Rats ; Rats, Wistar ; Toluene 2,4-Diisocyanate/*toxicity