Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment,

Abstract: Plastic debris is associated with several chemical pollutants known to disrupt the functioning of the endocrine system. To determine if the exposure to plastic debris and associated chemicals promotes endocrine-disrupting effects in fish, we conducted a chronic two-month dietary exposure using Japanese medaka (Oryzias latipes) and environmentally relevant concentrations of microplastic (< 1 mm) and associated chemicals. We exposed fish to three treatments: a no-plastic (i.e. negative control), virgin-plastic (i.e. virgin polyethylene pre-production pellets) and marine-plastic treatment (i.e. polyethylene pellets deployed in San Diego Bay, CA for 3 months). Altered gene expression was observed in male fish exposed to the marine-plastic treatment, whereas altered gene expression was observed in female fish exposed to both the marine- and virgin-plastic treatment. Significant down-regulation of choriogenin (Chg H) gene expression was observed in males and significant down-regulation of vitellogenin (Vtg I), Chg H and the estrogen receptor (ERα) gene expression was observed in females. In addition, histological observation revealed abnormal proliferation of germ cells in one male fish from the marine-plastic treatment. Overall, our study suggests that the ingestion of plastic debris at environmentally relevant concentrations may alter endocrine system function in adult fish and warrants further research.

Keywords: Plastic debris; Endocrine disruption; Japanese medaka; Germ
cells; Gene expression

Chelsea M. Rochman, Tomofumi Kurobe, Ida Flores, Swee J. Teh,

September 2014, Pages 656-661, ISSN 0048-9697,
http://dx.doi.org/10.1016/j.scitotenv.2014.06.051.
(http://www.sciencedirect.com/science/article/pii/S0048969714009073)