Screening for Aryl Hydrocarbon Receptor Activity in Ambient Air Using Passive Sampling (SPMDS) and CAFLUX

Abstract

Ambient air samples may be screened for aryl hydrocarbon receptor activity using bioassays such as CAFLUX. This screening may provide an estimate of overall potency which is then a function of all components of the complex mixture including uncharacterized components and may reduce the need for costly analysis in all cases. Passive air samplers are particularly suited for use as a screening tool due to their cost-effectiveness and capacity to be deployed over wide spatial scales simultaneously. In this study passive air samplers were deployed at five sites in Queensland, Australia. Co-deployed samplers were analysed for priority pollutant polycyclic aromatic hydrocarbons and the aryl hydrocarbon receptor activity of the samples from each site, were assessed using CAFLUX. TCDD Eq concentrations for each sample were determined. Samples from exposed sites were significantly different in response to the field blank response except for one site where samplers were deployed in a eucalypt forest. This activity could be detected from an equivalent air volume of < 2 m3 per well. This activity showed an apparent decrease with increasing distance from the central business district, for sites within the same air shed. These sample concentrations were converted to a TCDD equivalent air concentration and ranged from 0.045 0.64 pg.m-3. These specific sites were a eucalypt forest site in outer Brisbane and an inner urban site respectively. These levels are consistent with though lower than overseas estimates of aryl hydrocarbon receptor activity in ambient air.