Finnish Institute of Occupational Health, Topeliuksenkatu 41 B, P.O. Box 40, Työterveyslaitos, FI-00032 Helsinki, Finland.
Int J Environ Res Public Health. 2019 Apr 9;16(7):1256. doi: 10.3390/ijerph16071256.
A new method was developed to analyze the surface count of fibers in a variety of environments. The method entails sampling surfaces with the help of suction to a filter cassette holder containing a cellulose filter. The filters were collapsed using microwave digestion in dilute acid, and the fibers filtered to polycarbonate filters, gilded, and analyzed by scanning electron microscopy (SEM). The method was compared to traditional gel tape sampling as described in International Standards Organization (ISO) standard 16000-27, following analysis with phase contrast microscopy. The methods were compared in industrial environments and in office-type environments, with the concentration range studied spanning from 0.1 to 100,000 fibers/cm². The methods yielded similar results ( < 0.05) in concentrations from 100 to 10,000 cfu/cm², while the filter cassette method gave systematically higher results in high concentrations (>10,000 cfu/cm²) as well as in all office-type environments studied, where the fiber count ranged from 0.1 to 20 fibers/cm². Consequently, we recommend using the new method in working environments where the surface count is more than 100 fibers/cm², as well as in office-type environments where the fiber count is below 10 fibers/cm². It should be noted, however, that a similar limit of quantitation as with the gel tape method (0.1 fibers/cm²) requires sampling a minimum area of 100 × 100 cm² with the fiber cassette method. Using the filter cassette method will require new guide values to be formed for office-type environments, since the results are higher than with the gel tape method. Alternatively, if present guide values or limit values are to be used with the filter cassette method, conventions as to which fiber sizes to count should be set, since SEM analysis in any case will allow for including a larger size range than phase contrast microscopy (PM). We, however, recommend against such an approach, since fibers less than 1 µm in width may not be less harmful by inhalation than larger fibers.
一种新的方法被开发出来，用于分析各种环境中纤维的表面计数。该方法需要借助吸力将表面样本采集到一个装有纤维素滤膜的滤盒支架上。然后使用微波消解在稀酸中使滤膜坍塌，并将纤维过滤到聚碳酸酯滤膜上，镀金，然后通过扫描电子显微镜（SEM）进行分析。该方法与国际标准化组织（ISO）标准 16000-27 中描述的传统凝胶带采样方法进行了比较，之后使用相差显微镜进行了分析。该方法在工业环境和办公环境中进行了比较，研究的浓度范围从 0.1 到 100,000 纤维/cm²。在 100 到 10,000 cfu/cm²的浓度范围内，两种方法的结果相似（<0.05），而在高浓度（>10,000 cfu/cm²）以及所有研究的办公环境中，滤盒法系统地给出了更高的结果，这些环境中的纤维计数范围为 0.1 到 20 纤维/cm²。因此，我们建议在表面计数超过 100 纤维/cm²的工作环境中使用新方法，以及在纤维计数低于 10 纤维/cm²的办公环境中使用该方法。然而，需要注意的是，与凝胶带方法类似，滤盒方法的定量下限（0.1 纤维/cm²）要求用纤维盒法采集至少 100×100 cm²的最小面积。由于使用滤盒法的结果高于凝胶带法，因此需要为办公环境制定新的指导值。或者，如果要使用滤盒法使用现有的指导值或限量值，则应确定要计数的纤维尺寸，因为 SEM 分析无论如何都可以包括比相差显微镜（PM）更大的尺寸范围。然而，我们不建议采用这种方法，因为宽度小于 1 µm 的纤维通过吸入可能不会比较大的纤维危害更小。
