Trace contamination with dioxin-like chemicals: Evaluation of bioassay-based TEQ determination for hazard assessment and regulatory responses

Ilse Van Overmeire, George C. Clark, David J. Brown, Michael D. Chu, W. Marcus Cooke, Michael S. Denison, Willy Baeyens, Sarah Srebrnik, Leo Goeyens

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Many recent dioxin contamination events have been traced back to poisoned animal feed or feed ingredients. Therefore, enforcement authorities placed limits on the levels of dioxins in food and feed or implemented strict monitoring and control programs. The levels in force are generally expressed as TEQ values, which inherently accepts the underlying hypothesis that the effects of dioxin-like chemicals are additive. TEQ determination involves either chemo-analysis, with high-resolution gas chromatography in combination with high-resolution mass spectroscopy, or bio-analysis. Bio-analytical methods, more particularly the reporter gene expression method CALUX, are advantageous due to their high throughput rate and low cost. Moreover, the CALUX methodology detects the overall dioxin-like toxicity, rather than the limited number of compounds investigated by chemo-analysis. Bioanalytical methods such as CALUX also differ from chemo-analysis in that the contribution of antagonistic as well as synergistic effects, which violate the additivity principle, can be detected. The application of bio-analytical methods can facilitate a broader assessment of public health risks by intensifying the current monitoring programs in terms of both sample numbers and types. Bio-analysis provides information on the total dioxin-like activity of the samples under study (hazard assessment); however, chemo-analysis is still needed to identify the predominant contaminants (congener identification) for risk management.

Original languageEnglish (US)
Pages (from-to)345-357
Number of pages13
JournalEnvironmental Science and Policy
Issue number6
StatePublished - Dec 2001


  • Ah receptor
  • AhR, arylhydrocarbon receptor
  • ARNT, AhR nuclear translocator protein
  • Bio-analysis
  • Chemical activated luciferase gene expression (CALUX)
  • CYP1A1, cytochrome P450-1A1 gene
  • Dioxins
  • DRE, dioxin responsive element
  • Toxic equivalency (TEQ)

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Global and Planetary Change
  • Management, Monitoring, Policy and Law
  • Geography, Planning and Development


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