title: Anti-androgenic effects of sewage treatment plant effluents in the prosobranch gastropod Nucella lapillus.
abstract: Recent studies performed under laboratory conditions have shown that single exposure to high levels of several xenoestrogens is able to induce imposex in at least two neogastropod species. In an attempt to evaluate if xenoestrogens, at environmentally relevant conditions, do contribute to imposex induction, we have tested the effects of a mixture containing xenoestrogens (municipal sewage effluents) on imposex development in the dogwhelk Nucella lapillus. Exposure for 3 months to the raw (0.25% and 1%) and the final sewage effluent (12.5% and 50%) rendered no increase in the severity of imposex. Conversely, as exposure to high concentrations of natural steroids, estradiol and estrone, had previously been shown to partially rescue imposex development under laboratory conditions, we have also tested if exposure to the final sewage effluent could ameliorated the severity of imposex induction by tributyltin (TBT). The results demonstrated that co-exposure to the final sewage effluent leads to a decrease trend in the severity of imposex in the presence of TBT. Within the studied imposex parameters, the Relative Penis Size index (RPSI) was the most affected with a 50% decrease in the effluent 12.5% plus TBT exposed group and 25% decrease in the effluent 50% plus TBT, if compared with the TBT alone. Overall, our results give further support to the use of imposex in N. lapillus as a specific biomarker of TBT contamination. However, in areas of high inputs of sewage effluents, the assessment of TBT contamination by the use of the imposex phenomenon should ideally also include data on the tissue levels of butyltins.
authors.affiliation: CIMAR/CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal. santos@ciimar.up.pt
authors.forename: M M
authors.initials: MM
authors.lastname: Santos
authors.forename: M A
authors.initials: MA
authors.lastname: Reis-Henriques
authors.forename: R
authors.initials: R
authors.lastname: Guillot
authors.forename: D
authors.initials: D
authors.lastname: Lima
authors.forename: R
authors.initials: R
authors.lastname: Franco-Duarte
authors.forename: I
authors.initials: I
authors.lastname: Mendes
authors.forename: S
authors.initials: S
authors.lastname: Queirós
authors.forename: L Filipe C
authors.initials: LF
authors.lastname: Castro
mesh_terms: D000726:Androgen Antagonists / Q000032:analysis / Q000633:toxicity*; D000818:Animals; D001559:Benzhydryl Compounds; D012734:Disorders of Sex Development / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000032:analysis / Q000633:toxicity*; D004784:Environmental Monitoring / Q000379:methods; D004958:Estradiol / Q000032:analysis / Q000633:toxicity; D004967:Estrogens / Q000032:analysis / Q000633:toxicity*; D005260:Female; D049851:Gastropoda / Q000187:drug effects*; D008297:Male; D010413:Penis / Q000187:drug effects / Q000254:growth & development; D010636:Phenols / Q000032:analysis / Q000633:toxicity; D015203:Reproducibility of Results; D012722:Sewage / Q000009:adverse effects* / Q000737:chemistry; D046468:Sexual Development / Q000187:drug effects*; D014220:Trialkyltin Compounds / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D000098826:Bisphenol A Compounds
chemical_list: D000726:Androgen Antagonists; D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D004958:Estradiol; D004967:Estrogens; D010636:Phenols; D012722:Sewage; D014220:Trialkyltin Compounds; D014874:Water Pollutants, Chemical; C474055:octylphenol; C011559:tributyltin; C025256:nonylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds