小气道功能测定在粉尘作业人员职业健康监护及风险评估中的应用

目的]了解粉尘作业对员工呼吸功能的影响，探讨小气道功能测定在粉尘作业人员职业健康监护及尘肺风险评估中的应用。方法]2009年对某机械制造企业粉尘作业车间进行生产环境调查、粉尘浓度检测，对216名粉尘作业人员进行肺功能测定等职业健康检查及问卷调查。结果]粉尘作业人员用力呼气75％肺活量的瞬间流量（forcedexpiratoryflowat75％offorcedvitalcapacity，FEF75％）的中位数为79％，低于正常值，用力肺活量（forcedvitalcapacity，FVC）、第1秒用力呼气容积（forcedexpiratoryvolumeinonesecond，FEV1）、1秒率（FEVl／FVC）、最高呼气流量（peakexpiratoryflow，PEF）、用力呼气25％肺活量的瞬间流量（forcedexpiratoryflowat25％FVC，FEF25％）、用力呼气50％肺活量的瞬间流量（forcedexpiratoryflowat50％ofFVC，FEF50％）的均数或中位数都在正常范围内，PEF、FEF25％、FEF50％和FEF75％异常的人员比例明显增高，分别为21．30％、BO．56％、45．37％和50．00％，而且这些参数异常人员接尘工龄较短，中位数分别为3．5年、4年、5年和5年。FVC、FEV1、FEV1／FVC、PEF、FEF25％、FEF50％、FEF75％异常人员的胸片检查异常比例分别为55．56％、60％．00、0、21．74％、15．15％、23．47％、25．00％。将胸片异常组与正常组的肺功能进行比较，胸片正常组的PEF、FEF25％、FEF50％的参数值低于异常组，差异有统计学意义（P〈0．05）。工龄10年以上的粉尘作业人员FEV1、FEF25％和FEF75％异常比例高于工龄较短组（P〈0．05）。结论]粉尘作业人员存在气流受限、小气道功能障碍。随着接尘工龄的增加，FEV1、FEF25％和FEF75％异常人员有增多的趋势。该人群肺功能检查结果与胸片表现并不同步。在职业健康监护工作中，应对粉尘作业人员的肺功能尤其是小气道功能进行重点观察和动态对比分析，并将其作为尘肺风险评估的指标之一。建议在职业健康检查中将FEF25％、FEF50％、FEF75％等反映小气道功能的参数增设为监测指标。

Application of Small Airway Function Test in Occupational Health Surveillance and Risk Assessment of Workers Exposed to Dust

Objective ]To explore the impact of dust exposure on respiratory function, and to discuss the application of small airway function test in occupational health surveillance and pneumoconiosis risk assessment of workers exposed to dust. Methods ] A worksite survey of occupational environment and dust concentration was conducted in the dust workshop of a machinery enterprise in 2009. Occupational health examinations and questionnaires were provided to 216 workers exposed to dust. Results ] The median of forced expiratory flow at 75% of forced vital capacity （FVC） （FEF75%） in the selected workers was 79% （below the normal range）. The mean or median of FVC, forced expiratory volume in one second （FEV0, FEVJFVC, peak expiratory flow （PEF）, FEF25% and FEF50% were in the normal ranges. The proportions having abnormal PEF, FEF25%, FEF50% and FEF75% increased significantly, being 21.30%, 30.56%, 45.37% and 50.00% respectively, and the corresponding medians of dust exposure period were 3.5, 4, 5 and 5 years respectively. The proportions showing abnormal chest X-ray images in workers having abnormal FVC, FEV1, FEV1/FVC, PEF, FEF25%, FEF50% and FEF75% were 55.56%, 60.00%, 0, 21.74%, 15.15%, 23.47%, 25.00%, respectively. The values of PEF, FEF25%, FEF50% in workers showing normal chest X-rays were significantly lower than those with abnormal X-rays （P 〈 0.05）. The abnormal proportions of FEV1, FEF25% and FEF75% in workers exposed to dust over 10 years was significantly higher than those with shorter exposure period （P〈0.05）. Conclusion ] Workers exposed to dust suffered airflow limitation with small airway dysfunction. With the extension of dust exposure time-length, there is a rising tendency of the number of workers with abnormal FEV~, FEF25% and FEF75% values. The results of pulmonary function test and chest X-ray are not synchronized in this study. Small airway function could .be used as one of the dust exposure worker surveillance indicators for dynamic observation and analysis.