Abstract
Despite efforts to upgrade sewage treatment plants (STPs) in the last decades, STPs are still a major source for the contamination of surface waters, including emerging pollutants such as pesticides, pharmaceuticals, personal care products and endocrine disrupting chemicals (EDCs). Because many of these substances are not completely removed in conventional STPs they are regularly detected in surface waters where they have the potential to affect local macroinvertebrate communities. The objective of the current work was to investigate the impact of an estrogenic wastewater effluent on the key life-history traits of the freshwater amphipod Gammarus pulex. G. pulex was exposed in artificial indoor flow-channels under constant conditions to different wastewater concentrations (0%, 33%, 66%, 100%). In parallel the estrogenic activity of wastewater samples was determined using the yeast estrogen screen (YES). Estrogenic activities in the STP effluent were up to 38.6 ng/L estradiol equivalents (EEQ). Amphipods exhibited an increasing body length with increasing wastewater concentrations. Furthermore, we observed a shift of the sex ratio in favour of females, a significantly increased fraction of brooding females and increased fecundity indices with increasing wastewater concentrations. The increased body length is likely to be attributed to the additional nutrient supply while the occurrence of EDCs in the wastewater is the probable cause for the altered sex ratio and fecundity in exposed Gammarus cohorts.
Acknowledgments
The authors thank Simone Ziebart and Katrin Bender from the Department Aquatic Ecotoxicology for technical assistance and their practical help collecting the gammarids and the realisation of the flow-channel experiments. Gottfried Scherer and Dietrich Kopp from Goethe University are acknowledged for the construction of the flow-channels.
Funding
The present work was part of the project RiSKWa (Risk management of new contaminants and pathogens in the water cycle) and the joint research project TransRisk (Characterisation, communication and minimisation of risks of new contaminants and pathogens in the water cycle; research and development project support code: 02WRS1275B) funded by the Federal Ministry of Education and Research (BMBF).
Nomenclature
ANOVA | = | analysis of variance |
BPA | = | bisphenol A |
CAS | = | Chemical Abstracts Service |
CPOM | = | coarse particulate organic matter |
CPRG | = | chlorophenolred-β-D-galactopyranoside |
DOC | = | dissolved organic carbon |
E1 | = | estrone |
E2 | = | 17 β-estradiol |
EDC | = | endocrine disrupting chemical |
EEQ | = | estradiol equivalent |
EE2 | = | 17α-ethinylestradiol |
ERα | = | estrogen receptor α |
HLUG | = | Hessian Agency for the Environment and Geology (Hessisches Landesamt für Umwelt und Geologie) |
ISO | = | International Organisation for Standardisation |
n | = | number |
OECD | = | Organisation for Economic Co-operation and Development |
P | = | pump |
p | = | probability |
SEM | = | standard error of the mean |
STP | = | sewage treatment plant |
UV | = | ultraviolet |
YES | = | yeast estrogen screen |
w.w. | = | wet weight |