Calibration of two passive air sampler configurations for monitoring concentrations of hexabromocyclododecanes in indoor air

Abstract

While polyurethane foam (PUF) disk passive air samplers are employed increasingly to monitor persistent organic pollutants in indoor air, they essentially sample only the vapour phase. As a previous investigation of the vapour : particle phase partitioning of hexabromocyclododecanes HBCDs in (outdoor) air reported them to be present largely in the particulate phase, we monitored three offices using active air samplers. In each, ∼65% of HBCDs were present in the vapour phase, suggesting PUF disk passive samplers are suitable for monitoring HBCDs in indoor air. Concentrations in the three offices (239–359 pg ΣHBCD m⁻³) exceed substantially those reported in outdoor air from the United States (2.1–11 pg ΣHBCD m⁻³), but are in line with outdoor air from Stockholm. The relative abundance of the three principal diastereomers in office air was closer to that found in technical HBCD formulations (i.e. predominantly γ-HBCD) than in most US outdoor air samples. Time integrated air concentrations of α-, β-, and γ-HBCD were obtained for an office using a low volume sampler operated over a 50 d period alongside PUF disk samplers. This calibration exercise yielded the following passive air sampling rates for both a fully- and part-sheltered PUF disk sampler design: for α-, β-, and γ-HBCD, 0.87, 0.89, and 0.91 m³ d⁻¹ respectively (fully-sheltered) and 1.38, 1.54, and 1.55 m³ d⁻¹ respectively (part-sheltered). Deployment of the part-sheltered configuration yielded concentrations ∼35% lower than those obtained using a high volume sampler, consistent with PUF disk samplers measuring primarily the vapour phase.