This special section includes 4 original articles on the environmental fate and effects of 17α-trenbolone and 17α-estradiol. Three of these articles describe studies conducted to elucidate environmental fate properties of 17α-trenbolone and 17α-estradiol [1-3], whereas 1 article describes a study on the reproductive effects of these substances in fish .
These studies were conducted to support the environmental assessment of Synovex® ONE, an extended-release implant containing estradiol benzoate and trenbolone acetate for use in beef steers and heifers for increased weight gain and improved feed efficiency. The use of steroid hormones such as estradiol benzoate and trenbolone acetate, and their increased detection in water bodies, has led to an increased interest in the environmental fate and possible effects of these compounds in the environment.
The studies described in these 4 articles provide new information on some of the key environmental fate processes needed to understand environmental exposure of 17α-trenbolone and 17α-estradiol, and new information on the effects of these substances on the reproduction of freshwater fish. This type of information is useful for prospective risk assessment, as required for approval of veterinary medicines in the United States.
Jane P. Staveley
Exponent, Cary, North Carolina, USA