| RESEARCH IN THE GROUP |
Research in the Group for Reproductive, Endocrine and Environmental Toxicology (GREEN Tox)(formerly Section for Developmental and Environmental Toxicology,, Institute of Pharmacology and Toxicology, University of Zurich)Humans and animal populations are increasingly exposed to chemicals in the environment throughout their lifetime, during reproduction and ontogeny. GREEN Tox (Group for Reproductive, Endocrine and Environmental Toxicology) conducts research at two levels: (1) longterm toxicology of environmental chemicals (including cosmetics and flame retardants) with focus on endocrine effects, the developing organism and reproduction, and (2) development of new refined test methods for the characterization of endocrine activity and developmental toxicity of chemicals. Rational actions require reliable information. We are therefore working along two lines: conducting research and providing information to the scientific community and to the public. Current Research Projects on Endocrine Active Chemicals (Endocrine Disrupters)Endocrine active environmental chemicalsDuring the past decade, researchers realized that chemicals out of different classes, derived from human sources (pesticides, industrial chemicals, drugs) or plants (phytoestrogens), are capable to activate or block hormone receptors, in particular estrogen or androgen receptors. Chemicals may further interfere with synthesis and breakdown of steroid hormones. Such chemicals may affect hormone-regulated developmental processes in peripheral organs (reproductive tract) and in central nervous system (sexually dimorphic neuron groups), which may result in alterations of sexual behavior or other types of behavior. Chemical-induced developmental alterations have been observed in wildlife, and recently, effects on humans have been demonstrated in selected cases. The occurrence of endocrine active chemicals in the environment presents three main problems, identification and characterization of endocrine active chemicals, monitoring of endocrine activity in environmental samples and of endocrine effects in populations, and risk assessment (in particular of low-dose longterm exposure). We focus on cosmetics and flame retardants. Many chemicals in cosmetics are high production volume chemicals. Their dual role as compounds administered to humans and as chemicals released into the environment and entering the food chain has long been neglected. Some classes of flame retardants are now receiving more attention because they have been found to increase at an alarming rate in human and animal tissues. We follow a dual strategy: On one hand, we analyze endocrine activities of individual chemicals and mixtures of chemicals in vitro and in acute in vivo tests (uterotrophic assay), on the other hand, we study longterm effects of chemicals with identified endocrine activity, with emphasis on effects on reproduction and ontogeny. |
