WP8 Beyond Occurrence: Fate and Effects of Pharmaceutical and Other Emerging Wastewater Contaminants in Aquatic Systems
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(KHA-1117-840669) Sorption and degradation of trenbolone in soils.

Khan, B¹, Lee, L¹, Sassman, S², ¹ Department Of Agronomy, Purdue University, West Lafayette, IN, USA² Department Of Agronomy, Purdue University, West Lafayette, IN, USA

ABSTRACT- The ultimate fate of many excreted anabolic agents is unknown; however measurable amounts of hormones are released from farm animals and reach the environment. Trenbolone (17Beta-hydroxy-4, 9, 11-trien-3-one) is a synthetic androgenic steroid hormone currently used as a growth promoter for farm animals in several meat exporting countries. Trenbolone is administered in its acetate form (TBA) through a subcutaneous implant and hydrolyzed in the body to the trenbolone, which is the active hormone and potent anabolic agent with androgenic, gestagenic and anti-glucocorticoid effects. To aid in predicting the mobility and persistence of trenbolone in the environment, sorption and aerobic degradation studies were conducted with four soils representing a range of organic carbon (OC) content, pH, and % clay. Multiple concentration sorption isotherms were reasonably fit with a linear sorption model. The average OC-normalized sorption coefficient (Koc, L/kg) is 103.3, which is similar to what was previously observed for the natural androgen testosterone. As trenbolone is degraded, it appeared to rapidly re-distribute between the soil and aqueous phases such that sorption equilibrium was nearly maintained. Based on the consistency of Koc values among different soils, organic carbon appears to be the primary domain of sorption. Based on the Koc values and typical OC contents of agricultural chemicals, a large mass fraction of trenbolone and related metabolites will be associated with soil or manure solids. Trenbolone degraded to trendione under aerobic conditions with half lives of less than one week across soils also similar to testosterone. Therefore, although trenbolone has been reported to much longer half-live in anaerobic manure systems (7 to 8 months), once applied to an aerobic soil environment, it is likely to degrade rapidly.

Key words: Sorption, Sorption Coefficient(Koc), Androgenic Hormones, Trenbolone