Department of Safety Engineering, China Institute of Industrial Relations, Beijing, China.
Environ Health Perspect. 2010 Nov;118(11):1620-4. doi: 10.1289/ehp.0901178.
Long-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear.
In the current study, we examined temporal aspects of the exposure-response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers.
This prospective cohort study followed 447 cotton textile workers from 1981 to 2006. at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (< 5 and > or = 5 years).
Past exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired < 5 years before baseline than for those who were hired > or = 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough.
长期职业性暴露于含有内毒素的棉花粉尘与慢性呼吸道症状及用力呼气量（FEV1）的过度下降有关，但内毒素相关的慢性气流阻塞的机制仍不清楚。
在目前的研究中，我们研究了空气中内毒素暴露、FEV1 的纵向变化和中国棉纺织工人队列中呼吸道症状之间的暴露-反应关系的时间方面。
这项前瞻性队列研究从 1981 年到 2006 年随访了 447 名棉纺织工人，每 5 年随访一次。我们使用广义估计方程方法，根据过去的暴露（截至最近 5 年调查间隔开始时的累积暴露）和累积暴露（在最近的间隔内）来模拟 FEV1 水平和呼吸道症状，这些暴露与其他协变量进行了调整。模型按在职和退休工作状态以及在基线调查前（<5 年和≥5 年）的就业年限进行分层。
过去接触内毒素与退休棉纺织工人的 FEV1 水平下降有关。在所有棉纺织工人中，过去的暴露与那些在基线前<5 年雇佣的工人的 FEV1 下降更为相关，而与那些在基线后≥5 年雇佣的工人相比。近期内毒素暴露与棉尘病、慢性支气管炎和慢性咳嗽显著相关。
