Application of an aryl hydrocarbon receptor based screening assay for assessing U.S. EPA draft remediation goals for dioxin in soil and sediment samples

Abstract

An aryl hydrocarbon receptor (AhR)-based, real-time polymerase chain reaction (PCR) assay (Procept®) was used to determine dioxin-like compounds in soil and sediment samples from seven sites known to be contaminated by dioxin and related compounds. The biological equivalent quotient (BEQ) generated by the Procept® assay was compared with toxicity equivalent (TEQ) measurements by isotope dilution gas chromatography-mass spectrometry (GC-MS). This research demonstrated that the Procept® assay has several limitations, when compared with GC-MS, including poorer detection limits and precision, and increased sensitivity to a wide range of AhR agonists and antagonists, such as polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCBs). However, results indicate that the Procept® assay can be used as an effective screening technique for dioxin-like compounds at the EPA draft recommended interim preliminary remediation level for dioxin in soils of 72 pg/g TEQ.

Keywords:

• dioxin
• screening
• PCR
• soil and sediment

Acknowledgement

The U.S. EPA, through its Office of Research and Development, funded and managed the research described here under Contract No. EP-C-05-057 to Battelle Memorial Institute. It has been subjected to Agency review and approved for publication.