Madsen Anne Mette, Matthiesen Christoffer B, Frederiksen Margit W, Frederiksen Marie, Frankel Mika, Spilak Michal, Gunnarsen Lars, Timm Michael
The National Research Centre for the Working Environment, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark.
J Environ Monit. 2012 Dec;14(12):3230-9. doi: 10.1039/c2em30699a. Epub 2012 Nov 15.
Selection of sampling device, sampling location and period are important first steps in the measurement of exposure to bioaerosols in indoor air. The steps following the sampling include treatment of samples and laboratory analysis. In this study, settling bacteria, endotoxin, fungi and serine protease have been measured in Danish homes using Electrostatic Dust Fall Collectors (EDCs). The effects of the presence of occupants, sampling on open surfaces versus in bookcases and treatment of samples have been studied. Concentrations of bacteria and endotoxin were significantly higher when occupants were at home than when they were absent. Across homes, higher concentrations of fungi were found in spring than in winter, as was the total inflammatory potential, while higher concentrations of protease were found in winter than in spring. The placement of the EDCs in bookcases versus on an open surface significantly affected the measured concentrations of bacteria and endotoxin. Direct extraction of EDC cloths caused a higher measured concentration of bacteria, fungi and serine protease than if EDC cloths were extracted post-storage at -20 °C. Extraction of EDC cloths caused an average of 51% and 58% extraction of bacteria and fungi respectively. In conclusion, EDCs should be placed on open surfaces during the sampling, how much occupants are present in their home during sampling and sampling season should be considered, EDC cloths should not be stored in a freezer before extraction of microorganisms, but extraction suspensions can be stored at -80 °C without affecting the number of microorganisms significantly.
选择采样设备、采样位置和采样时段是测量室内空气中生物气溶胶暴露量的重要首要步骤。采样后的步骤包括样品处理和实验室分析。在本研究中，使用静电降尘收集器（EDC）对丹麦家庭中的沉降细菌、内毒素、真菌和丝氨酸蛋白酶进行了测量。研究了居住者在场的影响、在开放表面与书柜中采样以及样品处理的情况。居住者在家时细菌和内毒素的浓度显著高于不在家时。在各个家庭中，春季的真菌浓度高于冬季，总炎症潜力也是如此，而冬季的蛋白酶浓度高于春季。EDC放置在书柜中与放置在开放表面相比，对所测细菌和内毒素浓度有显著影响。直接提取EDC滤布所测细菌、真菌和丝氨酸蛋白酶的浓度高于将EDC滤布在-20°C储存后提取的情况。提取EDC滤布平均分别提取出51%的细菌和58%的真菌。总之，采样期间EDC应放置在开放表面，应考虑采样时家中居住者的数量和采样季节，提取微生物前EDC滤布不应储存在冰箱中，但提取悬浮液可储存在-80°C，且不会显著影响微生物数量。
