title: Utilizing the partitioning properties of silicone for the passive sampling of polychlorinated biphenyls (PCBs) in indoor air.
abstract: The former use of polychlorinated biphenyls (PCBs) in construction materials can lead to elevated indoor air concentrations. We studied the partitioning of PCB congeners between indoor air and silicone with a view to establish passive sampling of PCBs. The release of PCB congeners from silicone followed first order kinetics and confirmed air-side rate-limited mass transfer. Logarithmic elimination rate constants decreased linearly with the logKOA values of the PCB congeners, but varied in a non-linear way with air velocity. Linear uptake of PCBs was found for silicone disks (0.5 mm thickness) in a petri dish, while PCBs reached equilibrium in silicone-coated paper sheets (0.001 mm silicone on each side) exposed to indoor air for 1-2 weeks. The ratios of equilibrium concentrations in silicone and conventionally measured air concentrations were roughly comparable with silicone-air partition coefficients, but further research is required for the determination of silicone-air partition coefficients. Avoiding performance reference compounds (PRCs) because of the indoor setting, the two formats were calibrated against conventional active measurements. Comparisons of air concentrations derived from active and kinetic passive sampling showed a divergence by factors of 2.4 and 2.0 (median values) for the petri dishes and the silicone-coated paper, respectively. With promising results for sensitivity and precision, the calibration of kinetic passive samplers remains the main challenge and will need suitable, non-hazardous PRCs. Equilibrium sampling indicated promising alternatives.
authors.affiliation: Aarhus University, Department of Environmental Science, Frederiksborgvej 399, DK-4000 Roskilde, Denmark. Electronic address: kvo@envs.au.dk.
authors.forename: Katrin
authors.initials: K
authors.lastname: Vorkamp
authors.affiliation: Rambøll, Environment and Health, Hannemanns Allé 53, 2300 København S, Denmark.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Odsbjerg
authors.affiliation: Sweco Danmark A/S, Granskoven 8, 2600 Glostrup, Denmark.
authors.forename: Majbrith
authors.initials: M
authors.lastname: Langeland
authors.affiliation: Technical University of Denmark, Department of Environmental Engineering, 2800 Kgs. Lyngby, Denmark.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mayer
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis / Q000517:prevention & control; D003252:Construction Materials; D004784:Environmental Monitoring / Q000379:methods*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012828:Silicones / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D012828:Silicones; D011078:Polychlorinated Biphenyls
keywords: Air velocity; Buildings; Calibration; Equilibrium; Kinetics; Sampling rates