Probing the Primary Mechanisms Affecting the Environmental Distribution of Estrogen and Androgen Isomers

Abstract

Land application of animal manure has been identified as a source of natural and synthetic hormone contaminants that are frequently detected down-gradient of agricultural operations. Much research on the environmental fate of hormones has focused on the structural isomers most biologically active in mammals, e.g., the 17β-isomers of the estrogen estradiol (E2) and the synthetic androgen trenbolone (TB). However, recent work has shown that the Rand β-isomers of E2 and TB can cause comparable effects on certain aquatic species. To improve our understanding and ability to predict isomer-specific interactions with environmental sorbents, we measured the association (K DOC ) of the Rand β-isomers of E2 and TB as well as their primary metabolites (estrone and trendione) with two commercial dissolved organic carbon (DOC) sources by measuring both free and DOC-bound hormone concentrations. We also measured solventÀwater partition coefficients partitioning (K SW ) for the same hormones using hexane, toluene, and octanol. Log K DOC * , log K OC (OC-normalized sorption by soils), and K OW values are all greater for the β-isomer except between the E2 isomers. Theoretical descriptors reflecting electronic character and soluteÀsolvent interactions were calculated to elucidate isomer-specific behavior. Trends for log K OW and log K DOC among hormones as well as between isomers are explained reasonably well by computed electrostatic potential and H-bonding parameters.

Quantification of solute–solute interactions in steroidal hormone removal by ultrafiltration membranes

“…Within the literature, many studies have quantified the interaction of estradiol with natural organic matter (NOM), though there have not been as many studies for the other hormones. The K OM value for estradiol is similar to literature K OM values measured for Aldrich HA [32,33].…”

17β‐Estradiol and Testosterone Sorption in Soil with and without Poultry Litter

“…Ketones evidently react much more strongly with phenolic hydrogen donors than they do with carboxylic acid or alcohol hydrogen donors (Neale et al, 2009). Thus, estrone has a lower K ow value than estradiol because the hydrogen donor in octanol is an alcohol group, whereas estrone exhibits higher K d values than estradiol for sorbents dominated by phenolic hydrogen donors such as humic acid, tannic acid, and toluene (Neale et al, 2009; Qiao et al, 2011). This seems to be reflected in the spread of K d values for sorption of these compounds to soil across a range of studies.…”

Coupled reversion and stream-hyporheic exchange processes increase environmental persistence of trenbolone metabolites

“…Published partitioning coefficients for 17a-TBOH include linear distribution coefficient (K d ; 2.2-41.1 l kg À 1 ) with positive relationships with organic content, pH, clay fraction and cation exchange capacity of the soil [31][32][33] . Additional available partitioning coefficients include organic carbon normalized (log K oc ; 2.77±0.12), Octanol-water (log K ow ; 2.72 ± 0.02), Hexane-water (log K hw ; À 0.114 ± 0.006), chlorophyll-water (log K chw ; 3.36±0.01), cyclohexane-water (log K cyw ; 0.39±0.07) and toluene-water (log K tw ; 1.987 ± 0.01) partitioning coefficients 31,33 .…”

“…Additional available partitioning coefficients include organic carbon normalized (log K oc ; 2.77±0.12), Octanol-water (log K ow ; 2.72 ± 0.02), Hexane-water (log K hw ; À 0.114 ± 0.006), chlorophyll-water (log K chw ; 3.36±0.01), cyclohexane-water (log K cyw ; 0.39±0.07) and toluene-water (log K tw ; 1.987 ± 0.01) partitioning coefficients 31,33 . First-order biodegradation rates for 17a-TBOH were recently reported as 0.0034 h À 1 for 5°C and 0.0071 to 0.013 h À 1 for 20°C in aerobic batch microcosms 31 .…”