Adhikari Atin, Gupta Jayanta, Wilkins John R, Olds Rolanda L, Indugula Reshmi, Cho Kyungmin J, Li Chunlei, Yermakov Michael
Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267, USA.
Ann Occup Hyg. 2011 Apr;55(3):272-85. doi: 10.1093/annhyg/meq082. Epub 2010 Dec 20.
Greenhouse operations are an important sector of the horticulture industry, also known as the Green Industry. The objectives of this study were (i) to investigate exposure levels to airborne culturable fungi, bacteria (total culturable bacteria and actinomycetes), endotoxin, and (1→3)-β-D-glucan in three Midwest greenhouses during summer and winter using multiple exposure assessment methods; (ii) characterize the load of microorganisms on greenhouse floors and determine potential microbial source strengths of the floors for aerosolizing microbial biocontaminants, and (iii) to estimate the prevalence of rhinitis, wheezing, asthma, and other respiratory symptoms/conditions among greenhouse workers.
Stationary inhalable aerosol samples were collected from each greenhouse using Button Inhalable Aerosol Samplers. Control samples were collected from offices and nearby outdoor locations. A microbial source strength tester was used to examine the aerosolization potential of microbial contaminants from greenhouse floors. Additionally, surface samples were collected by sterile cotton swabs. Temperature, relative humidity, and wind velocity were recorded. Airborne culturable fungi, bacteria, and actinomycetes were analyzed in the extracts from field samples by cultivation in nutrient agar media. Endotoxin and (1→3)-β-D-glucan in the extracts from field samples were analyzed by specific kinetic chromogenic Limulus amebocyte lysate assays. The prevalence of respiratory symptoms among greenhouse workers (n = 35) and control subjects (office workers; n = 14) was estimated with a standardized questionnaire.
The collected data indicate that workers employed in Midwest greenhouses may be exposed to elevated levels of inhalable culturable microorganisms (fungi and bacteria collectively on the order of 10(2)-10(5) CFU m(-3)), endotoxin (10(1)-10(3) EU m(-3)), and (1→3)-β-D-glucan (10(1)-10(2) ng m(-3)). Seasonal variations were observed for some bioaerosol components. The prevalence of self-reported respiratory symptoms was generally higher among greenhouse workers compared to controls; however, the differences were not statistically significant, likely due to the relatively low statistical power of the study.
温室作业是园艺产业的一个重要部门，也被称为绿色产业。本研究的目的是：（i）在夏季和冬季，使用多种暴露评估方法，调查美国中西部三个温室中空气传播的可培养真菌、细菌（总可培养细菌和放线菌）、内毒素和（1→3）-β-D-葡聚糖的暴露水平；（ii）表征温室地板上的微生物负荷，并确定地板将微生物生物污染物雾化的潜在微生物源强度；以及（iii）估计温室工人中鼻炎、喘息、哮喘和其他呼吸道症状/疾病的患病率。
使用纽扣式可吸入气溶胶采样器从每个温室收集固定的可吸入气溶胶样本。从办公室和附近的室外地点收集对照样本。使用微生物源强度测试仪检查温室地板上微生物污染物的雾化潜力。此外，用无菌棉签收集表面样本。记录温度、相对湿度和风速。通过在营养琼脂培养基中培养，分析现场样本提取物中的空气传播可培养真菌、细菌和放线菌。通过特定动力学显色鲎试剂法分析现场样本提取物中的内毒素和（1→3）-β-D-葡聚糖。使用标准化问卷估计温室工人（n = 35）和对照受试者（办公室工作人员；n = 14）中呼吸道症状的患病率。
收集的数据表明，美国中西部温室中的工人可能接触到较高水平的可吸入可培养微生物（真菌和细菌合计约为10² - 10⁵ CFU m⁻³）、内毒素（10¹ - 10³ EU m⁻³）和（1→3）-β-D-葡聚糖（10¹ - 10² ng m⁻³）。观察到一些生物气溶胶成分存在季节性变化。与对照组相比，温室工人中自我报告的呼吸道症状患病率总体上更高；然而，差异无统计学意义，可能是由于该研究的统计效力相对较低。
