What are environmental hormones?
The female sex hormone, estrogen, controls the growth of cells. It does this by attaching itself to proteins called estrogen receptors throughout the body. There are also estrogens in the environment that can attach themselves to these same proteins. Environmental estrogens block the body’s estrogens and may cause health problems. Environmental estrogens are all around us―in what we eat, drink, the air we breathe, in things we use at home, and at work. They include things such as: • DDT and kepone—chemicals once found in pesticides. They break down slowly in the environment and may stay for years in soil and water. • Polychlorinated biphenyls—a mixture of chemicals once used as coolants in electrical devices. They are still in the air. • DES or diethylstilbestrol—until banned in the 1970s, used to prevent miscarriage in women.
Pesticides, plastics, herbicides and a wealth of other new chemicals contain man-made estrogen. People are assaulted today by hormones in meats, dairy products, and drugs, such as hormone replacement therapy. It has only been in the last 5-10 years that people are stating to realize how common environmental hormones are in modern society. These environmental hormones can be toxic to the body by increasing the estrogen levels many times higher than normal. For example, there has been a link between pesticides and breast cancer.
The endocrine systems is comprised of a set of glands and the hormones they produce that help guide development, growth, reproduction and behavior of animals including human beings. Some of the endocrine glands include the pituitary, thyroid and adrenal glands, the female ovaries and male testes. Hormones are chemicals produced by endocrine glands that travel through the bloodstream and cause responses in other parts of the body. Examples of hormones include adrenaline, which helps stimulate physical activity, and estrogen, which is essential for female reproductive function. Hormones can produce both positive and negative effects. For example, some types of breast cancer are exacerbated by estrogen. Chemicals that interfere with the normal functioning of this complex system are known as “endocrine disruptors.” Disruption of the endocrine system can occur in various ways. For example, some chemicals may mimic a natural hormone, “fooling” the body into over-responding to the hormone.
The term environmental hormone is commonly used to describe environmental agents that can alter the endocrine system of humans and wildlife. Fundamental research has taught us that the endocrine system is made up of specialised cells and glands under the control of a network of chemical signals or hormones. This communication network responds to stimuli by releasing hormones, the chemical messengers that carry instructions about essential bodily functions to target “receiver” cells throughout the body. The instructions are read by receptors within or on the surface of the “receiver” cell. Some hormonal instructions cause short term temporary changes, such as a faster heart beat. Others dictate more long-term development, such as initiation of the menstrual cycle or even bone or muscle growth, or development of the reproductive organs (ovaries and testes) in the developing foetus.
The female sex hormone, estrogen, controls the growth of cells. It does this by attaching itself to proteins called estrogen receptors throughout the body. There are also estrogens in the environment that can attach themselves to these same proteins. Environmental estrogens block the body’s estrogens and may cause health problems. Environmental estrogens are all around us―in what we eat, drink, the air we breathe, in things we use at home, and at work. They include things such as: • DDT and kepone—chemicals once found in pesticides. They break down slowly in the environment and may stay for years in soil and water. • Polychlorinated biphenyls—a mixture of chemicals once used as coolants in electrical devices. They are still in the air. • DES or diethylstilbestrol—until banned in the 1970s, used to prevent miscarriage in women. Some daughters of women who took DES during pregnancy have had reproductive problems and rarely, vaginal or cervical cancer, when they reached childbearing age.
