Environmental estrogens: A silent enemy

Abstract

Throughout our lives we are exposed to environmental estrogens, from food, air, water, soil, and household products as well as probably through breast milk or during development in the womb. Environmental estrogens have endocrine disrupting activity. Many times natural plant compounds or synthetic chemicals may also disturb the endocrine system. These compounds are weaker than the estrogen naturally produced in the body. Many reproductive, developmental and other health problems have also been linked to these substances when used in lab animals and wildlife. The contaminants derived from estrogenic sources are used for various purposes. They are used to make plastics, pesticides and other commercial products. The potency of natural hormones is greater than any synthetic estrogen except for drugs like diethylstilboestrol (DES). Several factors influence estrogen production (gender, age and reproductive cycle). The majority of natural estrogens are short-lived, do not accumulate in tissues, and are rapidly degraded in the liver. Synthetic environmental estrogens such as beta-hexachlorocyclohexane (beta-HCH), estrogenic drugs such as ethinylestradiol diethylstilbestrol (DES), OPP' DDT, polychlorinated biphenyls (PCBs), 4-nonylphenol (NP) and phytoestrogens such as isoflavones or lignans, are more stable and remain in the body longer than natural estrogens. Animal and human fat and tissues tend to accumulate most of these compounds since they are lipophilic. Environmental estrogens, in turn, may mimic, block or cancel out the effects of natural estrogen, based on the natural estrogen levels. In this review we discuss the effects of environmental estrogens on human health.