PARENT SESSION
18 - Endocrine Disruption
8:00 AM to 6:30 PM, Monday, 13 May 2002
Exhibition Area

(18-16) Estrogenic potency of ingested PAH contaminated soils.

Van de Wiele, Tom^*,1, Siciliano, Steven¹, Verstraete, Willy¹, ¹ Ghent University, Gent, Belgium

ABSTRACT- The estrogen receptor is present in the human intestinal cell wall suggesting that contaminated soil ingestion may be an important exposure route to environmental endocrine disrupters. Some polycyclic aromatic hydrocarbons (PAH) are estrogenic, but it is not known if PAHs released in the gastrointestinal tract retain their estrogenic activity. A PAH contaminated soil from a recreation area (50 + 1.1 g PAH/g DM) was digested using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME) and 6.8 g/L total PAH content was observed in stomach extracts, 5.7 in the duodenum and 10.6 in the colon. These extracts were screened for their ability to interact with the human estrogen receptor using a Yeast Estrogen Screen bioassay. Estrogene concentrations peaked in the duodenum with 38 ng/L 17-ethynyl estradiol equivalents, followed by the colon, 32 and stomach, 30. PAH dependent estrogenic effects were highest in the duodenum with an EC50 values of 1.01 g PAH/L followed by the colon, 1.26, and the stomach 1.19. In contrast, extracts of non-digested soils contained lower 17-ethynyl estradiol equivalents of 28 ng/L with a PAH EC50 that shifted to a higher concentration of 1.38 g/L. These data indicate that gastrointestinal processes increase the amount of estrogenic potency of PAHs present in soil.

Key words: estrogen, PAH, ingestion, soil