Submitted to: Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2007
Publication Date: 12/12/2007
Citation: Zheng, W., Yates, S.R., Bradford, S.A. 2007. Analysis of Steroid Hormones in a Typical Dairy Waste Disposal System. Environmental Science and Technology. Vol 42:2 Interpretive Summary: The occurrence of steroidal hormones in aquatic environments is receiving considerable attention since many of these compounds can interfere with normal functioning of the endocrine system of humans and animals. Two common sources of steroidal hormones are municipal sewage treatment plants and concentrated animal feeding operations. To minimize and avoid the potential hormone inputs from dairy waste products, the proper treatment and disposal of solid manure and manure-containing wastewater is very important. However, there is currently little information pertaining to the prevalence of hormones and their metabolites in dairy waste-disposal systems. It remains unclear what levels of steroids could be introduced into fields from agricultural practices, and whether the dairy waste treatment poses any risks to surrounding aquatic environments. The objectives of this research was to develop an accurate, and reliable method to detect low levels of steroid hormones in soil, water and manure complexes and to investigate and evaluate the types of hormones that occur in dairy waste systems in California. This information will increase our understanding of the types and amounts of steroidal hormones that occur in dairy waste, and the potential contribution of dairy facilities as a source of these compounds.
Technical Abstract: The environmental loading of steroid hormones contained in dairy wastes may cause a potential adversely affect on the aquatic species. This work was to investigate the profile of steroid hormones in a typical dairy waste operation system and assess the potential risk of hormone contaminations resulting from land application. Simple and quantitative methods were developed to monitor low-level steroid hormones in complex matrix samples. The preparation method for wastewater analysis consists of solid phase extraction and purification steps, which allows removing the sample matrix interference and achieving low detection limits for the quantification of hormones of interest. Precision of the method was high and the average recoveries were >80% for all steroid hormones except medroxyprogesterone, indicating that the methods are satisfactory for the monitoring of dairy wastes involving solid and liquid samples. The methods developed were applied to the survey of hormones in dairy wastes. The endogenous hormones 17-[alpha]-estradiol, 17-[beta]-estradiol, and estrone were detected in the dairy wastewater and lagoon water. The high concentration of 17'-estradiol in fresh dairy wastewater rapidly decreased along the sewage lane because the chemical can readily transform to its metabolite, estrone. The levels of total steroid hormones in the lagoon water were approximately 1~3 orders of magnitude lower than those in the dairy wastewater. The use of sequencing lagoons may remove the hormones and minimize their loads to the environment from land application. In fresh and piled solid manure samples, four steroid hormones were quantified with relative high concentrations. The piling of solid dairy wastes is a good and easy agriculture practice to reduce the hormone load because steroid contaminants may be readily degraded by manure microorganisms.