Institute of Environmental Assessment and Water Research (IDÆA-CSIC), C/ Jordi Girona 18, 08034 Barcelona, Spain; Barcelona University, Chemistry Faculty, C/ de Martí i Franquès, 1-11, 08028 Barcelona, Spain.
National Research Centre for the Working Environment, Lersø Parkallé 105, Copenhagen DK-2100, Denmark.
Sci Total Environ. 2019 Feb 10;650(Pt 2):2423-2436. doi: 10.1016/j.scitotenv.2018.09.379. Epub 2018 Oct 2.
Modelling of particle exposure is a useful tool for preliminary exposure assessment in workplaces with low and high exposure concentrations. However, actual exposure measurements are needed to assess models reliability. Worker exposure was monitored during packing of an inorganic granulate fertilizer at industrial scale using small and big bags. Particle concentrations were modelled with one and two box models, where the emission source was estimated with the fertilizer's dustiness index. The exposure levels were used to calculate inhaled dose rates and test accuracy of the exposure modellings. The particle number concentrations were measured from worker area by using a mobility and optical particle sizer which were used to calculate surface area and mass concentrations. The concentrations in the worker area during pre-activity ranged 63,797-81,073 cm, 4.6 × 10 to 7.5 × 10 μm cm, and 354 to 634 μg m (respirable mass fraction) and during packing 50,300 to 85,949 cm, 4.3 × 10 to 7.6 × 10 μm cm, and 279 to 668 μg m (respirable mass fraction). Thus, the packing process did not significantly increase the exposure levels. Chemical exposure was also under control based on REACH standards. The particle surface area deposition rate in respiratory tract was up to 7.6 × 10 μm min during packing, with 52%-61% of deposition occurring in the alveolar region. Ratios of the modelled and measured concentrations were 0.98 ± 0.19 and 0.84 ± 0.12 for small and big bags, respectively, when using the one box model, and 0.88 ± 0.25 and 0.82 ± 0.12, when using the two box model. The modelling precision improved for both models when outdoor particle concentrations were included. This study shows that exposure concentrations in a low emission industrial scenario, e.g. during packing of a fertilizer, can be predicted with a reasonable accuracy by using the concept of dustiness and mass balance models.
颗粒物暴露建模是在低浓度和高浓度工作场所进行初步暴露评估的有用工具。然而，需要进行实际暴露测量以评估模型的可靠性。在使用小袋和大袋进行工业规模的无机粒状肥料包装过程中，监测工人的暴露情况。使用一个和两个箱式模型对颗粒物浓度进行建模，其中排放源使用肥料的扬尘指数进行估算。使用吸入剂量率和暴露模型测试准确性来评估暴露水平。使用迁移率和光学粒子计数器在工人区域测量颗粒物数浓度，并将其用于计算表面积和质量浓度。在预活动期间，工人区域的浓度范围为 63,797-81,073 cm，4.6×10 到 7.5×10 μm cm，354 到 634 μg m（可吸入质量分数），在包装过程中为 50,300-85,949 cm，4.3×10 到 7.6×10 μm cm，279 到 668 μg m（可吸入质量分数）。因此，包装过程并未显著增加暴露水平。根据 REACH 标准，化学暴露也得到了控制。在包装过程中，颗粒物在呼吸道中的表面积沉积率高达 7.6×10 μm min，其中 52%-61%的沉积发生在肺泡区域。使用一个箱式模型时，模型化和测量浓度的比值分别为小袋和大袋的 0.98±0.19 和 0.84±0.12，使用两个箱式模型时，比值分别为 0.88±0.25 和 0.82±0.12。当包含室外颗粒物浓度时，两种模型的建模精度都得到了提高。本研究表明，在低排放工业情况下，例如在肥料包装过程中，可以使用扬尘和质量平衡模型的概念，以合理的精度预测暴露浓度。
