Does perfluorooctanoic acid represent potential risk to fish fecundity?

Endocrine disrupting (ED) chemicals act in very small amount and in subtle ways, adversely affecting reproduction of wildlife. The ED activity of perfluorooctanoic acid (PFOA), an emerging pollutant ubiquitously found, was studied in adult common carp, Cyprinus carpio. The effects of waterborne 56-days exposure to PFOA were evaluated at 200 ng/l, a concentration reported in the field and thus of environmental relevance, and at 2 mg/l, taking into account different levels of organization (i.e. organismal, histocytological, molecular/transcriptional). There were no significant differences in gonado-somatic index among the groups. Gonads of carp exposed to 200 ng/l, similarly to those of control fish, had PFOA levels under the limit of detection (LOD=0.4 ng/g ww) and no signs of histopathological changes. Oocytes degeneration and altered spermatogenesis were found in carp exposed to 2 mg/l, which gonads showed PFOA concentrations > LOD. The expression levels of aromatase gene (ARO), coding for the steroidogenic-key enzyme converting testosterone to estrogens, were altered in carp exposed at both concentrations: expression increased in testes and decreased in ovaries. In conclusion, environmental PFOA concentration did not elicit histological damages in the gonads but affected ARO expression, raising concern that exposure to this pollutant may lead to reproductive impairment.