PCB-contamination in a school building indoors

Abstract

Today substantial amounts of PCB still remain in buildings. PCB is found to be used in different building materials as a plasticizer, e.g. in paints and elastic sealing materials. PCB was used in building materials especially in 1960s but also in the late 1950s and early 1970s. The purpose of the study was firstly to find and to analyze PCBs used in paints in Finnish buildings indoors. The question of the amount of hazardous materials in buildings was approached by a case study in a basement of a school building containing PCB-paint. After analyses the purpose was to remove the PCB-paint and to see what issues there are to be concerned about once the PCB-paint is mechanically removed. At first the original PCB concentrations were analyzed. The greyish floor paint contained PCBs of about 8 751 mg/kg. The red paint in walls had concentrations of 23 mg/kg. Since the wall concentration was low, there was no need to remove that mechanically. Renovation of the room was performed as the floor paint was removed. Since sandblasting creates a lot of dust, other methods were applied. The floor paint was removed by grinding. After the removal of the floor paint, all of the surfaces in a room were washed with detergent water. The PCB concentrations were analyzed from wipe samples taken after the paint removal prior to washing and again after the washing. The results show that by removing the floor paint and by washing all the surfaces the concentrations in the room were reduced but PCBs were not totally removed. After grinding and washing, the floor had PCB concentration of about 4 019 mg/kg. The results show significant PCB-concentrations still after the paint itself had been removed. It was calculated that originally about 118 g of pure PCB was present in floor paint in a room of 12 m2. After removal of the floor paint, the total PCB still present in the room was about 58 g. By grinding most of the visible paint, the total reduction of PCBs was about 52%. © 2010 WIT Press.