Development of Passive Samplers for Measuring Indoor Air Concentrations, and Measurement of Physical and Chemical Properties of Semi-Volatile Organic Compounds.

摘要

Human exposure to semi-volatile organic compounds (SVOCs) including flame retardants (FRs) and plasticizers used in consumer products from indoor sources is a serious concern. These compounds are then advected to the outdoor environment which leads to regional and long-range transport and exposure to the ecosystem. This thesis aims to improve our understanding of exposure to selected SVOCs by developing tools, methods and providing data to facilitate exposure assessment particularly regarding indoor air. Three new passive air samplers (PAS), namely silicone rubber (polydimethylsiloxane, PDMS), styrene-divinylbenzene copolymer (XAD)-Pocket and XAD-PDMS were calibrated against an active air sampler and compared to the more popular polyurethane foam (PUF) PAS. Although the indoor sampling rates vary, we recommend from these studies a generic sampling rate of 1.7 m3 day-1dm-2 and 0.94 m3 day-1dm-2 for PDMS and PUF, respectively.;The active air sampler was also used to assess the gas-particle distribution of the target compounds. The particle-phase partitioning fractions of SVOCs is a key determinant of their environmental behaviour and potential for exposure thus toxicity. A key finding here, is that some relatively volatile organophosphate ester FRs are present in the gas-phase where most published studies of active air sampling report them largely in the particle phase, indicating a sampling artifact. To improve chemical screening and modelling of the transport and fate, this thesis provides experimentally determined values of vapour pressures and octanol-air partition coefficients for over 50 SVOCs measured here using the well-established gas chromatography retention time method.;Deployment of PDMS and PUF in residential homes gave comparable estimates of air concentrations for SVOCs in the gas-phase, although PUF was more able to capture compounds with higher fractions in the particulate phase. PDMS shows promise as a tool for estimating exposure to a wide range of SVOCs indoors, although its particle sampling efficiency warrants further work.