PARENT SESSION

2I - High-tiered Studies
Hall 7
8:30 AM - 12:30 PM, Monday, 28 April 2003
Chair: Streloke, M.¹, ¹
Co-chair: Schutz, R.², ²

(MO7/7) Substance dynamics of bisphenol-A in artificial indoor streams and effects on aufwuchs.

Licht, Oliver¹, Ladewig, Vanessa², Ludwichowski, Kai-Uwe², Jungmann, Dirk², Nagel, Roland², ¹ BUA-Office Ecotoxicology, Dresden, Germany, Germany² University of Technology, Dresden, Germany, Germany

ABSTRACT- Bisphenol-A is an important industrial chemical with an estimated production within the EU of 700,000 tonnes/year. The wide distribution (bisphenol-A can be found in the water of several rivers in Germany with concentrations up to 0.78 g/L) and its potential to act as an endocrine disruptor leads to controversial discussions. These discussions are still going on, in spite of or even as the EU Risk Assessment Report has been published. The effects of bisphenol-A on aufwuchs (mainly algae) were investigated in artificial indoor streams over a period of 103 days. Three concentrations (5, 50 and 500 g/L) were tested. The substance was applied weekly. The dissipation of bisphenol-A from the water phase was investigated in detail 3 times during the experiment. Bisphenol-A in the water was analysed with HPLC. DT₅₀-values were about 1 day after a lag phase of approximately 4 - 7 days with no trend to a further reduction during the experiment. The dynamics of aufwuchs was investigated on artificial substrates (unglazed ceramic tiles, n = 3 per sampling date from each stream) in a 14-day interval. The aufwuchs on the tiles was quantified by ash free dry weight. With the data from each stream the area under curve was calculated and EC_X-values (based on nominal concentrations) were obtained using probit-transformation. The EC₁₀ is 33 g/L and the EC₅₀ 520 g/L. These results are 2- to 5-times lower (based on the nominal EC₅₀-values) compared with results from standard algae test (E_bC₅₀, 96 h) with 2,700 g/L for green algae and 1,000 g/L for diatoms. But in the standard algae test the exposure regime is continuous in contrast to the decreasing concentration in the stream experiment. Under a continuous exposure regime the long-term effects on aufwuchs would be stronger.

Key words: aufwuchs, artificial indoor streams, bisphenol a, long-term effects