The paper presents results of statistical analyses of indoor PCB air concentrations related to building characteristics, time trends and resident behavior. More than 150 measurements of air concentrations were made in five high-rise apartment buildings with PCB containing sealants in an estate in Denmark. The indoor air concentrations consists of two datasets. Data set A are short-term nighttime measurements in both kitchen and living room taken during the period from 2010 to 2017. Data set B consists of 24-h measurement taken in the living room late 2017. Data set B also holds information from a questionnaire of among other things cleaning habits filled out by the residents and concentrations of PCB in dust from the vacuum cleaner bag of the homes. Both data sets show higher air concentrations associated with higher indoor temperature. Data set A further show, that this was associated with wintertime and it is speculated, that the higher air concentrations in cold weather are due to underfloor PCB sources being heated by radiator pipes. Building, floor level and apartment type were used as variable as the apartments were very similar and the type included many characteristic parameters. No relations were seen between air concentrations and these parameters. Repeated measurements of air concentrations from a number of apartments between 2010 and 2017 showed some variation over time, though no clear tendency was observed. Frequent cleaning habits had a minor influence on lowering the air and dust concentrations.