Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
Finnish Institute of Occupational Health, Työterveyslaitos, Finland.
Ann Work Expo Health. 2019 Apr 19;63(4):468-479. doi: 10.1093/annweh/wxz016.
In real-world applications, implementation of an enclosure and negative pressurization is not always adequate to prevent the dispersion of dust from renovation sites. This study aimed to quantify the effect of local exhaust ventilation (LEV) in controlling the dust concentration within an enclosed renovation site to reduce the dust dispersion into adjacent areas.
The concentrations of inhalable and respirable dust were measured in 16 cases during renovation projects. Filter samples and time-resolved dust concentration data were collected simultaneously from the renovation site and adjacent areas to assess the efficacy of LEV in limiting the dust dispersion.
The dispersion of dust outside of the enclosed renovation sites was limited significantly with using LEV. The estimated dust removal efficiency of LEV was 79% for inhalable dust concentration in the renovation site and 62% in the adjacent area. The use of LEV reduced the concentration of respirable dust by 33‒90% in the adjacent area and 80-87% within the renovation site.
Using LEV was found to play a substantial role in dust containment, particularly when the enclosure failed to maintain the negative pressure. The study provides data-driven recommendations that are of practical importance as they promote healthier workplaces and policy improvements. In conclusion, dust dispersion into adjacent areas is prevented with an airtight enclosure (including airlocks) and continuous negative pressure. Dust containment was also obtained by having target dust concentration at the enclosed renovation site to below 4 mg m-3 for inhalable dust and below 1 mg m-3 for respirable dust, even though the enclosures not being continuously under negative pressure. The suggested target concentrations are achievable by using on-tool LEV during the most dust-producing tasks.
在实际应用中， enclosure 和 negative pressurization 的实施并不总是足以防止灰尘从翻新现场扩散。本研究旨在量化局部排气通风（LEV）在控制封闭翻新现场内粉尘浓度以减少灰尘向相邻区域扩散的效果。
在 16 个翻新项目期间测量了可吸入和呼吸性粉尘的浓度。从翻新现场和相邻区域同时收集滤料样本和时变粉尘浓度数据，以评估 LEV 在限制粉尘扩散方面的效果。
使用 LEV 可显著限制封闭翻新现场外的灰尘扩散。LEV 的估计粉尘去除效率为翻新现场中可吸入粉尘浓度的 79%，相邻区域的 62%。LEV 的使用使相邻区域中呼吸性粉尘的浓度降低了 33-90%，在翻新现场内降低了 80-87%。
使用 LEV 被发现对粉尘控制起到了重要作用，尤其是当 enclosure 未能维持负压时。该研究提供了数据驱动的建议，对于促进更健康的工作场所和政策改进具有实际意义。总之，通过使用密闭 enclosure（包括气闸）和持续的负压，可以防止灰尘进入相邻区域。通过将封闭翻新现场内的目标粉尘浓度控制在可吸入粉尘 4mg/m³以下和呼吸性粉尘 1mg/m³以下，也可以实现粉尘控制，即使 enclosure 没有持续处于负压状态。通过在最产生粉尘的任务期间使用工具上的 LEV，可以实现建议的目标浓度。
