Occurrence and Characterization of Steroid Growth Promoters Associated with Particulate Matter Originating from Beef Cattle Feedyards

Abstract

Studies of steroid growth promoters from beef cattle feedyards have previously focused on effluent or surface runoff as the primary route of transport from animal feeding operations. There is potential for steroid transport via fugitive airborne particulate matter (PM) from cattle feedyards; therefore, the objective of this study was to characterize the occurrence and concentration of steroid growth promoters in PM from feedyards. Air sampling was conducted at commercial feedyards (n = 5) across the Southern Great Plains from 2010 to 2012. Total suspended particulates (TSP), PM10, and PM2.5 were collected for particle size analysis and steroid growth promoter analysis. Particle size distributions were generated from TSP samples only, while steroid analysis was conducted on extracts of PM samples using liquid chromatography mass spectrometry. Of seven targeted steroids, 17α-estradiol and estrone were the most commonly detected, identified in over 94% of samples at median concentrations of 20.6 and 10.8 ng/g, respectively. Melengestrol acetate and 17α-trenbolone were detected in 31% and 39% of all PM samples at median concentrations of 1.3 and 1.9 ng/g, respectively. Results demonstrate PM is a viable route of steroid transportation and may be a significant contributor to environmental steroid hormone loading from cattle feedyards.

Ractopamine in particulate matter emitted from beef cattle feedyards and playa wetlands in the Central Plains

“…Ractopamine concentrations observed in the present study were similar to concentrations of antibiotics (up to 4.5 mg/g monensin and chlortetracycline; McEachran et al 2015) and higher than concentrations of steroids (up to 60 ng/g; Blackwell et al 2015) in PM samples collected from the same region. Ractopamine and antibiotics have similar daily dosages (max 420 mg/head/day ractopamine for up to 42 d, Elanco Animal Health 2017a; max 480 mg/head/day monensin for entire time on feed, Elanco Animal Health 2017b), whereas steroids are administered as time-release FIGURE 2: (A) Ractopamine concentration in air, (B) ractopamine concentration in particulate matter, and (C) particulate matter concentration in air collected upwind and downwind of beef cattle feedyards.…”

“…These have focused on water around agricultural production facilities in Nebraska, with ractopamine detected in a beef cattle production facility's wastewater lagoon ( 261 ng/L; Bartelt-Hunt et al 2011), in surface waters in effluent-dominated areas ( 1.2 ng/L; Brown et al 2015), and in a mixed-use agricultural watershed (< 0.1 ng/L; Jaimes- Correa et al 2015). Based on previous research documenting transport of veterinary pharmaceuticals in feedyardemitted PM (steroids, Blackwell et al 2015;antibiotics, McEachran et al 2015), we hypothesized that ractopamine would also be transported from feedyards via PM. Feedyards in this region do, however, generate considerable fugitive airborne particulate matter (PM) emissions.…”

“…Fine particulate fractions of feedyard PM (< 7.5 mm) have been shown to persist 3.5 km downwind at > 99% of initial concentrations (Hiranuma et al 2011), suggesting that chemicals affiliated with feedyard PM are indeed transported into the surrounding environment. Based on previous research documenting transport of veterinary pharmaceuticals in feedyardemitted PM (steroids, Blackwell et al 2015;antibiotics, McEachran et al 2015), we hypothesized that ractopamine would also be transported from feedyards via PM. We theorized that this PM is then deposited into the surrounding environment, including into playa wetlands that are the predominant aquatic systems in parts of the Central Plains.…”

A critical review of the environmental occurrence and potential effects in aquatic vertebrates of the potent androgen receptor agonist 17β‐trenbolone

“…Hence, aquatic species would be most prone to unintended exposures. However, there is at least some potential for exposure in terrestrial environments, either through land‐applied manure from treated animals (Lange et al ; Jones et al ) or via aerial transport of trenbolone acetate metabolites associated with dust (Blackwell et al , ; Wooten et al ).…”

“…Additional empirical data concerning the persistence of 17β‐trenbolone under different use/degradation scenarios and climatological conditions also would be valuable. For example, although recent studies suggest that aerial transport of 17β‐trenbolone can occur (Blackwell et al ), data concerning this phenomenon are relatively limited. Basically, at present, there are insufficient empirical data to conduct a robust probabilistic assessment of exposure for aquatic organisms to 17β‐trenbolone.…”