Atmospheric volatile organic compound monitoring. Ozone induced artefact formation.

Assessment of population exposure to VOC in ambient atmospheres is receivin g heightened interest as the adverse health effects of chronic exposure to certain of these compounds are identified. Active (pumped) and passive samp lers are the most commonly used devices for this type of monitoring. It has been shown, however, that these devices, along with all other preconcentra tion techniques, are susceptible to ozone interference. It is demonstrated that this interference occurs even at low ozone concentrations and that it may result in the under-estimation of population exposure. A convenient and effective ozone scrubbing method is identified and successfully applied an d validated for both active and passive samplers for a range of VOC.