The effect of ventilation on the indoor air concentration of PCB: An intervention study

• Investigation of the effect of ventilation on PCB indoor air concentration.
• Highest reduction of indoor air concentration of PCBs ranged between 30 and 46%.
• A constant emission rate model overestimates the reduction in concentration.
• PCB emission rate is directly proportional to air exchange rate.

The impact of increased ventilation on polychlorinated biphenyl (PCB) air concentration by installation of mechanical balanced ventilation units was studied. The intervention was carried out in three PCB-contaminated rooms; one classroom in an elementary school and two small bedrooms in an apartment in a residential building. In the classroom, the air exchange rate (ACH) was raised from 0.2 (without mechanical ventilation) to 5.5 h−1 during the intervention. In the two bedrooms, the highest ACH was 6.6 h−1 and 0.5 h−1 without mechanical ventilation. The corresponding concentration decrease achieved from the intervention was 30% and in one of the bedrooms 45%. Emissions of PCB rose dramatically during periods of increased ventilation as the drop in concentration did not match the increased ACH. When ventilation in the bedrooms was increased incrementally from 0.5 to 2.2, 4.5, and 6.6 h−1, emissions were found to increase linearly with increasing ACH. Compared with the sparse literature regarding estimated reductions due to ventilation, the measured effect on concentrations was less than expected.