New Low Cost Method for Sampling Svocs in Ambient Air

The Lancaster Environment Centre, (UK) one of Europe’s largest environmental research centres, has developed innovative passive air samplers for sampling semivolatile organic contaminants (SVOCs) such as polycyclic aromatic hydrocarbons, brominated flame retardants and ‘dioxins’. Whereas passive sampling of ambient air for pollutants such as NOx and SO2 is well developed, the development of such techniques for SVOCs represents an exciting but emerging field.

SVOCs in ambient air are typically measured using active samplers which require expensive equipment, a secure site, power and trained operatives. Until now such measurements have therefore been relatively expensive. The new passive samplers offer many advantages which include simplicity, lower cost, versatility and the capability of being deployed in many locations concurrently.

The samplers have been designed and calibrated to allow reliable estimates of air concentrations to be made, or to allow semiquantitative comparisons of the levels and patterns of SVOCs. Several designs have been developed which can integrate ambient concentrations over time scales as short as hours and as long as years. The shorter timescales facilitate studies of contaminant dispersal, fluxes and transport processes and can provide data for dispersion and transport modelling. Longer timescales allow source/sink regions to be identified and underlying trends in ambient levels to be investigated.

More recent developments of the passive sampler have provided not only concentration data but also directional information which will yield invaluable data for source apportionment.

The simple and versatile design of passive air samplers provides a wide range of possible applications including background air measurements, indoor air quality assessments, occupational hygiene studies, within site boundary investigations and spatial surveys around point sources.