PCB in air, dust and surface wipes in 73 Danish homes

As part of an investigation of the total indoor exposure of residents in PCB contaminated apartments in a building estate in Denmark, 73 homes were visited. Samples of air, vacuum cleaner dust and surface wipes were taken and analysed for 15 PCB congeners. The 53 apartments located in high-rise buildings with indoor PCB containing sealants showed significant elevated total concentrations of PCB in air, dust and surface wipes compared to 20 reference homes. The average concentration in exposed homes was 2330 ng PCB_total/m³ in air, 12.000 ng PCB_sum15/g in dust and for surface wipes 529 ng PCB_sum15/wipe. These values were respectively 40, 25 and 50 times higher than the averages found in reference homes. The air concentration in all exposed homes was higher than the lower recommended action level of 300 ng PCB_total/m³ from the Danish Health Authority, whereas all reference homes were below. The air concentrations in exposed homes were variating, partly due to indoor temperature. The concentrations in air and dust samples were significantly correlated for PCB_sum7 in exposed homes. No significant correlation was observed between samples of air and surface wipes, despite surface wipes from exposed homes were significantly different from wipes taken in reference homes. Both dust samples and surface wipes have a potential as screening tool for identifying elevated levels of the less chlorinated PCBs in air. Additional short-term measurements of air concentrations in a subgroup of exposed homes indicated limited diurnal variations within the individual homes. The congener patterns were rather uniform within the respective media from the exposed homes and dominated by tri- and tetraPCBs. The pattern of air differed from that of dust and surface wipes, which were more alike. The study demonstrates a wide spread PCB contamination of the indoor environment in buildings with PCB in indoor sealants and confirms the need for identifying and alleviate PCB in buildings causing a health concern to the occupants.