554 trends in analytical chemistry, vol. 16, no. 10, 1997 Detection of endocrine-disrupting pesticides by enzyme-linked immunosorbent assay (ELISA): application to atrazine Jordi Gas&n, Anna Oubiiia, Damih Barcel6* CID-CSIC, Department of Environmental Chemistry, c/Jordi Girona 18-26, 08034 Barcelona, Spain An overview of biological and toxicological effects of relevant endocrine-disrupting com- pounds is given. Special attention is paid to the determination of atrazine, a relevant pes- ticide that is considered an endocrine dis- rupter, by ELISA. 0 1997 Elsevier Science B.V. 1. Introduction The Worldwatch Institute estimates that there are about 70 000 synthetic chemicals in everyday use, with between 500 and 1000 new chemicals being added to the list each year [ 11. It is estimated that over 700 different organic compounds, particularly pesticides and their breakdown products, surfac- tants, phenols and polycyclic aromatic hydrocar- bons, may be found in drinking water. Perhaps one of the most pertinent issues as far as risk assess- ment is concerned is that the effects of long-term exposure to trace levels of chemical pollutants are by no means clear. Many of these chemicals can disturb development of the endocrine system and of the organs that respond to endocrine signals in organisms indirectly exposed during prenatal and / or early postnatal life [ 2 1. Hormones influence many aspects of the body, regulating its metabolism, and affecting sexual characteristics. Oestrogens are the hormones that *Corresponding author. Tel.: + 34 (3) 400-61718. Fax: + 34 (3) 204-5904. influence the development and maintenance of female sex characteristics, and the maturation and function of the sex organs, and testosterone serves a similar function for males. The most important oes- trogen is 17-P-oestradiol. During sexual differen- tiation there are a number of critical periods when the reproductive system is uniquely susceptible to chemically induced perturbations. At these times an inappropriate chemical signal can result in per- manent and irreversible lesions that often result in infertility, whereas similarly exposed young adults are only transiently affected. The strict definition of an oestrogenic chemical is a chemical which can imitate an oestrogen, nor- mally 17-P-oestradiol. However, this term is also frequently used to refer to chemicals which are able to disrupt the hormonal systems of males or females; more accurate terms for these chemicals are hormone-disrupting or endocrine-disrupting. There are many factors which influence whether a chemical will affect a human or animal, including how the chemical enters the body, how it is distrib- uted and what hormonal and other processes it interacts with. These endocrine-disrupting chemicals can come from the diet, such as the phytoestrogens coumes- trol and genistein, or from the environment (e.g., op’-DDT, and polychlorinated biphenyls (PCBs)), where they are produced as pesticides and wastes from manufacturing processes. Besides a relative requirement for a phenolic ring, the array of chem- ical structures and substitutions found in environ- mental compounds makes prediction of oestro- genie potency difficult [ 3 1. Also, many of the endocrine disrupters are persistent, lipophilic, and have low vapour pressures, which facilitates their widespread dispersal [ 2 1. There are many ways to disrupt the hormone system, Some involve interaction with a receptor, some involve the production or elimination of hor- mones and receptors, and all involve interference with the normal hormonal messages which need to be delivered for normal development and behav- iour to occur [ 4-9 1. 0165-9936/97/$17.00 PLJSO165-9936(97)00051-4 0 1997 Elsevier Science B.V. All rights reserved.