Pölynhallinta korjausrakentamisessa:Loppuraportti hankkeesta: Epäpuhtauksien hallinta saneeraushankkeissa. Puhdas ja turvallinen saneeraus

Procedures and instructions for the control of impurities during building renovation processes were created. Sufficient impurity controls are a necessity to provide healthy and comfortable conditions for construction workers and people occupying areas beside construction sites. Target values and suitable measuring methods for impurities were also developed. The study was performed among seven renovation targets in which the exposure of construction workers and spread of impurities outside construction sites were assessed. Participative information gathering tools motivated construction workers to improve their working habits and achieved a safer work environment. The developed query tool was suitable for the risk assessment and survey of work places. Constructors and contractors can use the query tool as a part of their quality management.Local exhaust ventilation (LEV) equipment significantly reduced workers' exposure to dust. However, during some demolition and grinding activities, concentrations of inhalable dust and respirable silica exceeded the limit values. Thus, the use of respirator protectors (RPs) is essential to protect workers' health. Fine dust can spread widely around the work site; thus, RPs should also be used in less-dusty work phases. This study showed that LEVs limited the spread of impurities outside the construction site. In addition, an airtight partitioning and continuous negative pressure between the construction site and adjacent area efficiently prevented the spread of dust into adjacent areas. Moreover, building an anteroom for passages helped the control of pressure differences during door traffic. We recommend the target value of -5 to -15 Pa for the negative pressure between the construction site and adjacent areas. The negative pressure should be monitored continuously throughout the renovation. Self-monitoring of impurity concentrations with real-time optical devices is recommended. However, optical results for each type of dust have to be corrected with mass-based correction factors. For passive use, optical devices are suitable to ensure the performance of dust controls by analyzing the concentration variation over time. In accordance with the dust concentration measurements at construction sites, we recommend construction site target values of 5 mg/m3 for inhalable dust, 0.5 mg/m3 for respirable dust and 0.05 mg/m3 for respirable silica. The target value for adjacent areas is given as a PM10-concentration of 50 µm/m3 with a 95% persistency. Well planned and comprehensively implemented dust control promotes renovation works, minimizes health and safety risks, reduces the need for extensive final cleaning, and is therefore cost-effective