Editors' ChoiceEcology

Return of the Steroid

Sci. Signal.  22 Oct 2013:
Vol. 6, Issue 298, pp. ec256
DOI: 10.1126/scisignal.2004825

Trace levels of organic contaminants enter aquatic ecosystems from a variety of sources, including runoff from agricultural lands. When these compounds and their metabolites break down, it is generally assumed that they become inert and pose less ecological risk. Qu et al. tracked the sunlight-mediated transformation of metabolites of trenbolone acetate (TBA)—a common growth-promoting steroid given to beef cattle—across a number of conditions in the laboratory and in the field. When the degradation products were exposed to dark conditions after photodegradation, they surprisingly reverted back to TBA metabolites, including analog steroidal compounds similar to TBA with unknown biological effects.

S. Qu, E. P. Kolodziej, S. A. Long, J. B. Gloer, E. V. Patterson, J. Baltrusaitis, G. D. Jones, P. V. Benchetler, E. A. Cole, K. C. Kimbrough, M. D. Tarnoff, D. M. Cwiertny, Product-to-parent reversion of trenbolone: Unrecognized risks for endocrine disruption. Science 342, 347–351 (2013). [Abstract] [Full Text]