Sorption of estrone and estrone‐3‐sulfate from CaCl₂ solution and artificial urine in pastoral soils of New Zealand

Abstract

Abstract-Estrone (E1) and its sulfate conjugate estrone-3-sulfate (E1-3S) are released to the environment in animal wastes in significant amounts, and direct exposure occurs in grazed pasture systems. Both compounds have been shown to potentially contribute to endocrine disruption in wildlife, and knowledge about the sorption behavior of these compounds is necessary for a sound risk assessment. For labile compounds such as E1 and E1-3S, however, the standard protocols might overestimate sorption by not considering metabolite formation or allowing for equilibration that exceeds the commonly reported half-lives of these compounds. We therefore conducted modified batch sorption experiments with 0.005 M calcium chloride (CaCl 2 ) and artificial urine solution to determine the influence of the mediator solution on the sorption of E1 and E1-3S in three pasture soils from New Zealand. Sorption isotherms of both compounds were nonlinear, and the Freundlich equation was found adequate to describe the isotherms. The sorption potential of E1-3S was about one order of magnitude lower than for the free counterpart, and the K f values significantly changed between the two mediator solutions. The calculation of concentration-dependent effective distribution coefficients (K eff d ) revealed that for a range of realistic exposure concentrations in a grazed dairy system, the common approach of using CaCl 2 would deliver incorrect inferences for a sound risk assessment.

The effect of particle size on sorption of estrogens, androgens and progestagens in aquatic sediment

“…The correlation between hormone sorption and surface area has been observed previously, with higher degree of hormone sorption observed for montmorillonite clays with potential for intercalation [32]. Scherr et al [41] found that sorption of estrogens to agricultural soils was limited by the number of sorption sites available, and that these sorption sites were allocated primarily within the organic matter domain of the soils. This finding may also explain the correlations between hormone sorption, OC, and SA.…”

Sorption of 17β-Estradiol to Pig Slurry Separates and Soil in the Soil-Slurry Environment

“…It thus appears that determination of E2 sorption to soil–slurry mixtures in CaCl 2 would severely overestimate the true sorption in slurry‐amended soil. The results support the conclusion by Scherr et al (2009) that the presence of urine leads to reduced sorption.…”

“…It is not known how slurry separation affects the environmental fate of estrogens, but quantification of estrogen sorption to different particle size fractions may be an important first step to evaluate the potential for removing estrogens by slurry separation and to estimate the distribution, persistence, and leaching potential of estrogens in the liquid fraction applied to soil. The majority of sorption experiments have been conducted in water (Ying et al, 2003) or 0.01 mol L −1 CaCl 2 (Casey et al, 2003; Casey et al, 2005; Das et al, 2004; Lee et al, 2003; Stumpe and Marschner, 2009), but recent studies have proposed the use of animal urine as a better representation of the chemical conditions in slurry (Lucas and Jones, 2009; Scherr et al, 2009). Ions and DOC from urine may occupy sorption sites of soil and slurry particles and thus affect sorption of estrogens to the solid phase (Stumpe and Marschner, 2010), and estrogens may complex to DOC present in the urine, thereby reducing sorption to the solid phase.…”

Fate and transport of free and conjugated estrogens during soil passage

“…Therefore, the knowledge of all compounds present along with the soil and hydrochemical properties is important to understand their fate and transport behavior. Recent studies have examined the fate and transport of sulfate-or glucuronide-conjugated estrogens in soils (Scherr et al, 2008(Scherr et al, , 2009a(Scherr et al, , 2009bShrestha et al, 2012). For example, in the study of Scherr et al (2008) which is based on batch experiments, a fast degradation of estrone-3-sulfate (E1-3S) to the metabolite E1 was observed; however, transport experiments were not performed.…”