Distribution and Relocation of Manure Borne Natural Estrogens in Agricultural Soils.
Josefine Beck1, Kai Totsche2, and Ingrid Kögel-Knabner1. (1) Technische Universität München, Lehrstuhl für Bodenkunde, Wissenschaftszentrum Weihenstephan, Freising, D-85350, Germany, (2) Universität Jena, Fachgruppe Hydrogeologie, Burgweg 11, Jena, D-07749, Germany
Feminisation of male fish in rivers makes us think about endocrine disrupting effects of artificial and natural substances released to the environment. Manure is one source of natural estrogens and is spread on agricultural soils regularly. These estrogens may reach ground and surface water e.g. by seepage, interflow or overland flow. There are investigations about sorption and degradation of estrogens in soils but less is known about field situation, estrogen input and their distribution. We investigated the fate of the principal natural estrogens of dairy manure in soils: 17α-estradiol, 17β-estradiol, estrone and estriol. Field samples of crop land and pastures that are used in different intensity should give information about estrogen amounts and distribution in soils. 4 crop land plots and 3 pasture plots were sampled in a regular orthogonal sampling grid with 5m spacing. Additionally batch and column experiments should elucidate potential degradation, sorption and transport of the estrogens. After pressurized liquid extraction and solid phase extraction estrogens were determined by GC-MS. In the crop land soil material of the estrogens were homogeneous distributed. Amounts about 10 ng kg-1 were found. The homogeneous manure spread by divers agricultural techniques and the intensive cultivation by e.g. ploughing are reasons for that findings. The estrogen concentrations founded are marginal for environmental risk assessment, if you consider an estimated input of 2.4 g estrogens per hectare and year, dilution effects and degradation. In contrast the estrogens in pasture soils were distributed inhomogeneous in amounts up to 120 ng kg-1. For input 1 g estrogens per hectare and year were estimated. Higher estrogen concentrations were found near the watering place and the paddock entrance. The cattle visits these places frequently and in high dense. According to high log KOC-values above 3 and the batch experiment results that showed a 90% estrogen reduction in the solution after 24h, a relocation of the estrogens seemed unlikely. In contrast we found low and increasing concentrations of the estrogens after 7 porevolumes in the column experiments. This could be either due to a transport of dissolved estrogens or due to a carrier facilitated transport of hormones bound to mobile organic or inorganic matter. Manure borne natural estrogens are found in environmental relevant concentrations. Their distribution is mainly determined by the way of input. In spite of a high rate of sorption and degradation a rapid relocation can't be excluded. Thereby intensive contaminated spots, like e.g. paddock entrances that additionally often have a minor soil infiltration by structural damages, represent a special risk.