Impact of Resident Density and Behaviour on the Indoor Air Concentration of Polychlorinated Biphenyls in Apartments

Background: PCBs are persistent organic chemicals that have serious impacts on sustainability from the perspectives of health and the environment. We investigated the impact of apartment size in combination with residential and behavioural factors on PCB concentrations in indoor air within contaminated apartments. Methods: Fifty-one apartments from a Danish complex were investigated for PCBs in 2017, including self-reported information about cleaning and ventilation. Results: Linear regressions showed that a high resident and pet density (m2 per person/pet) and, to some extent, a high resident density, were significantly correlated with lower indoor air concentrations of PCBs. Low indoor air temperature, high cleaning frequency, and open vent valves (ventilation) were other significant reducing factors. The average concentrations of PCBs in apartments with a resident density of 25 m2 per resident were 2000 ng/m3 and 1844 ng/m3 per resident/pet. These concentrations increased by 0.37% for each additional m2 per resident and by 0.70% for each additional m2 per resident/pet. Conclusions: Resident/pet density and, to some extent, resident density are significant modifiers of the indoor air content of PCBs in the investigated complex. Temperature, cleaning frequency, and blocking or unblocking of vent valves (ventilation) are behavioural factors related to residential and residential/pet density and significant modifying factors of the PCB indoor air concentration. This study confirms the importance of cleaning and ventilation.