Evaluation of Analytical Chemical Methods for Detection of Estrogens in the Environment

Evaluation of Analytical Chemical Methods for Detection of Estrogens in the Environment

1 Introduction

Many chemical substances display estrogenic activity and may be suspected of causing adverse effects in humans and/or environmental organisms (1). At present only a few examples provide evidence that the presence of chemicals released to the environment by human activities is causing adverse effects on environmental organisms.

Recently evidence was presented showing that steroid estrogens released from humans are the main causal agents for the feminisation of fish in an aquatic environment impacted by sewage (2;3). The chemicals causing these effects are the natural compounds estrone (E1), 17ß-estradiol (E2) and estriol (E3) and the synthetic estrogen, 17α-ethinylestradiol (EE2). A few other steroid estrogens are also reason for concern. The occurrence of these substances in the environment has hitherto mainly been considered as due to human release through sewage treatment, however, the question of whether release of farm animal waste (cattle and pigs) (17 α-estradiol (E2-17α) is a significant source for the observed effects remains unanswered.

Research focusing on assessing the extent, consequences and methods for solving the resulting problems is strongly dependent on reliable methods for detecting the substances and their metabolites in the environment. It has been shown that steroid estrogens are causing adverse effects in fish at concentrations as low as 0.1 ng/L (3). The lack of reliable analytical methods for analysing for steroid estrogens at such low concentrations (preferably lower) is a major impediment to the solution of this environmental problem. Even though a range of methods have been developed, the descriptions of these methods are scattered in the literature and an overview of these methods should be helpful. The objective of this report is to review the existing methods for detecting estrogens in relevant environmental matrices. This will be done with specific focus on the sensitivity of the methods, but as quality assurance and validation of the methods are very important, other parameters will also be considered in the assessment of the analytical methods.

For this purpose a number of delimitations are needed:
Methods that are not published in the scientific peer review literature will generally not be evaluated.
The diversity of the environment is enormous and therefore, a myriad of different environmental matrices exists. The matrices that will be covered in this report are:
- wastewater related matrices (sewage influent, effluent, and sludge)
- surface water and sediment
- manure, soil, and groundwater
Many of the papers cited in the current report will touch issues regarding pollution with estrogens and their environmental chemistry. As the current report is intended to address only analytical chemical information, it is outside the scope to comment on such issues.

The second chapter in this report discusses the background information needed to develop analytical methods for steroid estrogens. This includes physical and chemical data for the steroid estrogens. Furthermore, a brief overview of exposure routes will be given in order to identify the environmental matrices that are relevant for the current report. For these matrices the expected concentrations will be discussed together with the potential environmental impact. The third chapter describes the different techniques used for analysis of steroid estrogens. The purpose of this chapter is to give an overview of the analytical chemistry methods used in analysing for steroid estrogens. The fourth chapter describes the specific problems that can be encountered when analysing each relevant matrix. The best available methods will be identified for each matrix state. In chapter five the various analytical methods are compared for effectiveness with regard to sensitivity, variability, selectivity and costs. In the sixth chapter recommendations and perspectives are presented, and some conclusions are drawn. Appendices 1 to 4 give overviews of the various analytical methods considered in this study.