Manure-Borne Estrogens as Potential Environmental Contaminants:  A Review

Abstract

Livestock wastes are potential sources of endocrine disrupting compounds to the environment. Steroidal estrogen hormones such as estradiol, estrone, and estriol are a particular concern because there is evidence that low nanogram per liter concentrations of estrogens in water can adversely affect the reproductive biology of fish and other aquatic vertebrate species. We performed a literature review to assess the current state of science regarding estrogen physicochemical properties, livestock excretion, and the fate of manure-borne estrogens in the environment. Unconjugated steroidal estrogens have low solubility in water (0.8-13.3 mg L(-1)) and are moderately hydrophobic (log Kow 2.6-4.0). Cattle excrete mostly 17alpha-estradiol, 17beta-estradiol, estrone, and respective sulfated and glucuronidated counterparts, whereas swine and poultry excrete mostly 17beta-estradiol, estrone, estriol, and respective sulfated and glucuronidated counterparts. The environmental fate of estrogens is not clearly known. Laboratory-based studies have found that the biological activity of these compounds is greatly reduced or eliminated within several hours to days due to degradation and sorption. On the other hand, field studies have demonstrated that estrogens are sufficiently mobile and persistent to impact surface and groundwater quality. Future research should use standardized methods for the analysis of manure, soil, and water. More information is needed about the types and amounts of estrogens that exist in livestock wastes and the fate of manure-borne estrogens applied to agricultural lands. Field and laboratory studies should work toward revealing the mechanisms of estrogen degradation, sorption, and transport so that the risk of estrogen contamination of waterways can be minimized.

Fate and occurrence of steroids in swine and dairy cattle farms with different farming scales and wastes disposal systems

“…As shown in Table 5, the daily fecal estrogens excretions of a cow were 1820e4080 mg/d, which were higher than a sow (6.22e59.0 mg/ d), or other growth stage of swine and cattle in this present study, which is consistent with some previous results (Hanselman et al, 2003;Lange et al, 2002). Lange et al (2002) estimated that the daily fecal excretions of estrogens by cycling sow and cycling cow were 14 mg/d and 200 mg/d.…”

“…Lange et al (2002) estimated that the daily fecal excretions of estrogens by cycling sow and cycling cow were 14 mg/d and 200 mg/d. Hanselman et al (2003) estimated that fecal estrogen excretions were 6.1e97.6 mg/d per sow, and 192e7296 mg/d per cow. It is worth noting that the detected masses and rates of synthetic estrogens 17a-ethynyl estradiol and diethylstilbestrol in wastewater are much higher than those detected in feces (Table S7).…”

“…Only recently, the livestock source of steroids started drawing some interests, mainly in some natural steroids such as estrogens, with few studies on glucocorticoids, and synthetic steroids used in the livestock industry (Gadd et al, 2010;Hanselman et al, 2003;Kolodziej et al, 2004;Lange et al, 2002;Zheng et al, 2008). According to the estimation of Lange et al (2002), the steroids from swine and cattle sources contribute predominantly in total excretion mass of steroids when compared with other livestock sources in European Union and the United States.…”

Potential water quality impacts originating from land burial of cattle carcasses

“…The occurrence of 17β-estradiol at high concentrations relative to other waste streams characterized previously such as municipal wastewater effluents or lagoon wastewaters is notable considering the potential for endocrine disrupting effects at concentrations in the low ng/L range [23]. The occurrence of 17β-estradiol in the leachate with limited detections of 17α-estradiol seem contradictory to previous findings that indicate that beef cattle typically excrete larger amount of 17α-estradiol [23].…”

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

“…These studies have shed some light on hormoneÀDOC interactions, but do not include assessing isomeric differences or the androgens. This is of special importance considering the recent hormonal effects noted for both isomers, stereoselective sorption by soils, 12,13 and the fact that all animal wastes contain both E2 isomers 19 and for beef cattle wastes, both TB isomers. 20 To address these shortcomings, the partitioning of both E2 and TB isomers were examined, along with their primary metabolites estrone (E1) and trendione (TND) as model estrogens and androgens ( Figure SI-1), to two types of commercial DOC.…”