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The effects of natural steroid hormones in animal feces or sewage on physiological mechanisms of wild animals and humans have become a hot research topic in the environmental field (Leet et al., 2011; Ferrey et al., 2015; Zhang et al., 2021). Masculinized fish was found in the androstenedione-containing river receiving mill effluents, and the androstenedione has been revealed to cause androgenic effects on female mosquitofish (Jenkins et al., 2003). It is also frequently detected in wastewaters and concentrated animal feeding operations (CAFOs) lagoons worldwide in the following research (Chang et al., 2011; Liu et al., 2012; Bartelt-Hunt et al., 2011). Recently, potential environmental contamination risk with androstenedione caused by application of animal manure to fields has become a concern (Yost et al., 2014; Bartelt-Hunt et al., 2012; Zhang et al., 2019). Up to 800 ng·L−1 of androstenedione has been measured in livestock wastewater lagoons (Bartelt-Hunt et al., 2011). China has a total population of 7.6 × 109 livestock, including 100 million cattle, 660 million pigs and 650 million poultry (Liu et al., 2012). Yang et al. (2021) reported that androstenedione accumulates in the soil with long-term fecal application. Chinese researchers believed that androstenedione excreted by animals is worth notice and may pose potentially high risks to sensitive organisms in the receiving environment (Liu et al., 2012; Zhang et al., 2015; Huang et al., 2019).
Steroid hormones cannot degrade during composting completely (Zhang et al., 2019). After agricultural application, steroid hormones in animal manure were easily absorbed in soils and sediments owing to organic matter interactions (Lima et al., 2012; Ong et al., 2012). Kim et al. (2007) also confirmed that androstenedione adsorbed in soils within several minutes followed by a slow adsorption process. Due to its high adsorption by soils, the androstenedione thus has relatively low potential to migrate in soils (Yuan et al., 2020). The livestock grazing with direct access to the earth's surface water resulted in elevated androstenedione concentrations of up to 44 ng·L−1 in agricultural watersheds (Kolodziej et al., 2007). In a simulated rainfall field experiment (Mansell et al., 2011), six steroid hormones, including androstenedione, were detected in the runoff from a steer feedlot. Arnon et al. (2008) suggested that interactions between hormones and manure lead to enhanced soil transport, to depths of 32 m below a dairy-farm waste lagoon. Stump et al. (2010) proved that dissolved organic matter (DOM) from cattle manure decreased 17β-estradiol sorption on soils. Lucas and Jones (2006) reported that sheep urine enhances leaching through soil columns. Although it is reported that DOM may inhibit photodegradation of sex hormones (Young et al., 2013), there is no sufficient information available on the effect of manure DOM on androstenedione sorption.