Sex hormones originating from different livestock production systems: fate and potential disrupting activity in the environment

Abstract Endogenous hormones of human or animal origin have been reaching the environment for thousands of years, even though to an increasing extent due to growing population and more intensive farming. During the last decade the hormonal disrupting activity of different substances of both natural and anthropogenic origin, has been discussed for wildlife populations in various ecosystems and even for human fertility. So far, natural recycling has not been causally linked to any known severe adverse effect on wildlife or human endocrine system, but discussion on environmental endocrine disrupters has to be extended by this important aspect. The amount of sex steroids excreted by humans and livestock seems in the same order of magnitude, but the available data on their importance is still limited. Besides endogenous hormones, exogenous sex steroids used as anabolics in animals are excreted and reach the environment. The environmental fate of steroids originating from livestock excreta seems to be strongly influenced by storage conditions and also by the soil type of the fields where the dung is spread. Particle size and organic components strongly affect adsorption and migration in the soil. Our studies indicate that low concentrations of trenbolone and melengestrol acetate are very mobile in agricultural soils. However, both hormones have a high affinity to the organic fraction of the immobile phase leading to a high retardation within soil materials.