The impact of bioaerosols in municipal solid waste management is nowadays identified as a growing health concern worldwide. In this study, exposure to endotoxin in composting facilities and its association with lung function and clinical symptoms was investigated in Tehran municipal solid waste management complex (Aradkooh) as one of the largest solid waste management facilities in the Middle East. Airborne endotoxins were collected between June and July 2019 and the concentrations were determined by Limulus Amebocyte Lysate (LAL) method. Healthy workers with no history of respiratory disease were recruited and data on clinical symptoms (cough, phlegm, wheezing, dyspnea, fatigue, headache, eye irritation, runny nose, runny eyes, and sore throat) was obtained by the modified American Thoracic Society questionnaire, and spirometric measurement was performed by an expert. The binary logistic regression test was used and adjusted for confounding variables. The results didn't show any difference in lung function parameters (FEV₁, FVC, FEV₁/FVC, PEF, FEF_25–75%), and most of the respiratory symptoms despite a relatively high difference in the concentration of endotoxin observed in air samples of different locations. Only the increased risk of cough (OR 10.5, 95% CI: 2.4 to 44.8 in the moderately exposed group and 7.8, 95% CI: 1.6 to 39.1 in highly exposed ones), fatigue (OR 3.7, 95% CI: 1.2 to 11.7), and headache (OR 6.02, 95% CI: 1.4 to 24.5) were found in the exposed groups compared to controls after adjusting for age, active and passive smoking. However, findings of the study might be underestimated due to some issues including healthy worker effect, intra and intersubject variability, and self-reporting bias, thereby the results should be interpreted with caution. Although we did not find any relationship, due to the high concentrations of endotoxins observed in some sites, it is recommended to consider some possible prevention measures such as using personal protective equipment to reduce the exposure of workers at an acceptable level.

如今，生物气溶胶在城市固体废物管理中的影响已被确定为世界范围内对健康日益关注的问题。在这项研究中，在堆肥设施中暴露于内毒素及其与肺功能和临床症状的关系，在德黑兰市固体废物管理综合体（Aradkooh）中进行了调查，该综合体是中东最大的固体废物管理设施之一。在2019年6月至2019年7月期间收集了空气传播的内毒素，并通过Li变形细胞溶解（LAL）方法确定了浓度。招募了没有呼吸系统疾病史的健康工作者，并通过修改后的美国胸科协会问卷调查获得了临床症状（咳嗽，痰，喘息，呼吸困难，疲劳，头痛，眼刺激，流鼻涕，流眼和咽喉痛）的数据，肺活量测量由专家进行。使用二进制逻辑回归测试并针对混杂变量进行了调整。结果未显示肺功能参数（FEV₁，FVC，FEV ₁ / FVC，PEF，FEF _25–75％）和大多数呼吸道症状，尽管在不同位置的空气样本中观察到的内毒素浓度相对较高。只有咳嗽的风险增加（中度暴露组为OR 10.5，95％CI：2.4至44.8，高暴露组为7.8，95％CI：1.6至39.1），疲劳（OR 3.7，95％CI：1.2至11.7）调整了年龄，主动和被动吸烟后，与对照组相比，暴露组发现头痛（OR 6.02，95％CI：1.4至24.5）。但是，由于一些问题，包括健康工作者的影响，受试者内部和受试者之间的变异性以及自我报告的偏见，该研究的结果可能被低估了，因此应谨慎解释结果。尽管我们没有发现任何关系，但由于在某些位置观察到高浓度的内毒素，