Evaluation of real-world implementation of partitioning and negative pressurization for preventing the dispersion of dust from renovation sites

Objectives: The aim of this study was to assess the implementation of partitioning and the negative pressure method in limiting the dispersion of dust to areas adjacent to renovation sites. Methods: The pressure difference between the worksites and adjacent areas and PM10 concentrations in the both zones were measured in 12 renovation sites, and the factors affecting the prevention of dispersion of dust were assessed. Results: Poor implementation of partitioning and negative pressurization found in half of the renovation sites lead difficulties in achieving a proper negative pressure, causing dispersion of dust into adjacent areas. Main problems related to flimsy partitioning walls and poor air tightness of the enclosure. Dust concentrations in adjacent areas were substantially lower when natural ventilation in the renovation site was rejected and partitioning walls and their junctions to existing structures were sealed. In case of leaky enclosures, despite the high air exchange rates, a definite negative pressure could not be maintained. Instead, negative pressure minimum of -5 Pa was found to be sufficient for limiting the dispersion of dust from renovation sites. Conclusions: Improvement on implementation of dust controls is required through revising the guidance documents, education, and efficient supervision. This study revealed that the current Finnish practice to implement the negative pressurization based on the air exchange rate achieved with the portable exhaust fans alone is not reasonable to assure adequate dust containment. Continuous negative pressure minimum of -5 Pa is suggested, and it should be monitored with alarm devices throughout the renovation processes.