An assessment of in vitro androgenic activity and the identification of environmental androgens in United Kingdom estuaries

Abstract

Environmental androgens are a group of compounds that to date have received very little attention. In this study, a yeast-based androgen screen (YAS) was used to determine the level of in vitro androgenic activity in seven United Kingdom estuaries. Surface water, sediment pore water, and sediment particulate material solvent extracts collected from Southampton Water, the Thames, Mersey, Tees, Tyne, Clyde, and Forth were tested for in vitro androgenic activity. Eleven of the 41 surface water samples collected displayed androgenic activity >2 ng dihydrotestosterone (DHT) equivalents/L (3-9 ng DHT/L), while eight of the 39 sediment pore waters collected showed activity >45 ng DHT/L (51-187 ng DHT/L). High levels of androgenic activity were determined in the solvent extracts of sediments, with 10 of 39 samples exhibiting a level of androgenic activity >454 ng DHT/kg (1,020-15,300 ng DHT/kg). In vitro YAS testing of five selected sewage treatment works (STW) effluents entering these estuaries showed that measurable levels (34-635 ng DHT/L) of androgenic activity were observed in those receiving only primary treatment (Howdon STW and Irvine Valley Sewer) at the time of the survey. A toxicity identification evaluation (TIE) study of Irvine Valley Sewer effluent using the YAS assay was used to identify the natural steroids/steroid metabolites dehydrotestosterone, androstenedione, androstanedione, 5beta-androstane-3alpha,11beta-diol-17-one, androsterone, and epi-androsterone as responsible for 99% of the in vitro activity determined in the effluent.