|
 PARENT SESSION
49 - Predicting Pollution Effects in the Field
8:00 AM to 6:30 PM, Tuesday, 14 May 2002
Exhibition Area
(49-08) Effects of 17 -ethinyloestradiol on fathead minnow, Pimephales promelas: do proposed EQSs provide adequate protection to populations?
Grist, Eric1, Wells, Claire1, Whitehouse, Paul*,2, Crane, Mark1, Wilkinson, Helen3, 1 Royal Holloway University of London, Egham, UK2 National Centre for Environmental Toxicology, Marlow, UK3 National Centre for Ecotoxicology and Hazardous Substances, Wallingford, UK
ABSTRACT- Environmental Quality Standards (EQSs) have recently been developed for the synthetic steroid, 17-ethinyloestradiol (see poster by Young et al). A standard of 0.4 ngl-1 has been proposed, following extrapolation from long-term studies with various fish species exposed to 17-ethinyloestradiol. The critical (i.e. most sensitive and reliable) study was a full life cycle study using fathead minnow (Pimephales promelas) exposed to 17-ethinyloestradiol over a 289-day period (Laenge et al, 2001). Raw data from this study (age-specific egg and fry survival and reproduction data) have been analysed in Life Table Response Experiments and the effects of 17-ethinyloestradiol on  , the intrinsic rate of population growth, determined. Critical concentrations with respect to have been estimated and compared with those derived using conventional endpoints from life cycle studies. Furthermore, sensitivity and elasticity analyses confirm that the effect of 17-ethinyloestradiol on fertility is more marked than its effect on survival rates. Linear and quadratic regression yields ErC100 values (the concentration at which r=0 and in practice extinction is projected) of 3.08 and 3.38 ngl-1, close to the MATC of 2 ngl-1 for feminisation of exposed fish (from Laenge et al, 2001), with lower 95% CIs of 3.0 ngl-1 (linear) and 3.13 ngl-1 (quadratic). The significance of these summary statistics is discussed in relation to the level of protection afforded by the proposed standard for 17-ethinyloestradiol at the population level following long-term exposure.
Key words: 17-ethinyloestradiol, population growth, fathead minnow, EQS
|
