The Endocrine system basically manages many of our bodies life sustaining functions through the production, distribution and mangement of hormones. Hormones are chemical messengers that travel from the producing organs to other parts of the body via the bloodstream and in very specific amounts. These chemical messengers control and adjust the functions of the body.
The adrenal, pituitary, thymus, ovary, testicular, thyroid and pancreatic glands are part of the very complex endocrine system.
Endocrine disruptors are synthetic substances that interfere with normal functioning of the endocrine system or of parts of the system by mimicry or blocking of hormonal activity. Hormones can be altered, inappropriate production can be stimulated, or even the way that the hormones transport through the body when endocrine disruptors go to work.
Overall, there are many suspected endocrine disruptors, especially plasticizers, pesticides and many chemicals. Known disruptors are DES (diethylstilbesterol), Dioxins (Polychlorinated dibenzodioxins), DDT (dichlorodiphenyltrichloroethane) and PCBs (Polychlorinated biphenyls).
Endocrine disruptors enter the body through direct contact or by contaminated water, food or air. They tend to accumulate in fat, and are a concern when eating fatty meats and fish, which get exposure from the extended presence of endocrine disruptors in the aquatic environment. As a result, fatty meats and fish are often considered to be the major source of exposure for humans.
Other sources of exposure exist in industrial environments, in areas where agicultural operations involve the spraying and water table contamination of fungicides and pesticides, and most recently as they leach out of plastics which are used everywhere. The air contamination occurs with spraying and burning of materials that introduce the substances to the air.
Evidence of endocrine disruption manifests in animals mostly from disruptions of the reproductive systems, abnormal swelling of thyroid glands, and the presence of the chemicals in eggs. Lowered populations, signs of illness and other indicators have been observed.
DES was a synthetic hormone with medical applications. The most profound evidence of endocrine disruption in humans occurred during the 1950s and 1960s when women were prescribed a synthetic hormone, DES. The DES was intended to prevent miscarriages, but failed in that purpose. The damage was manifested in the children of the women, who developed vaginal cancers as well as birth defects in their reproductive and compromised immune systems.
As a result, one term and classification for endocrine disruptors as a threat to reproduction in top level predators, or animals at the top of the food chain.
PCBs were used most prominently in electric transformer fluids and have been banned since the late 1970s. Initially, seabirds presented illness that was later related to PCBs. Then humans developed symptoms of chloracne, rashes, indications of liver damage, lesions on the skin and in the eye, menstrual difficulties, poor cognitive development in children, and suppressed immune systems. Worse, PCBs were a prime example of the way in which endocrine disruptors enter the water and the body through fatty fish or at the workplace. Infants were affected in utero or recieved the chemicals through breast milk.
DDT is a synthetic pesticide that showed promise in the early 1940s as a way to control malaria and typhus. But DDT went on to being used in huge quantities and indiscriminately until it was banned in the early 1970s. DDT was a catalyst in the inception of the environmental movement. In humans, DDT metabolizes into DDE, which is an antiandrogen. DDT and DDE have been linked to diabetes, neurological disorders, congenital disorders and reproductive problems. Rachel Carson’s landmark text “Silent Spring” was the catalyst for worldwide action to ban the use of DDT. But, DDT can be used, rarely, for barbituate poisoning and was used
Dioxins are the products of combustion, chlorine and some manufacturing processes. They are known to relate to birth defects, changes to the DNA of an individual, and cancers. Dioxins can occur naturally from such events as volcanic eruptions and fires.But human production is said to account for most of Dioxin production. Such substances as Agent Orange, the chemical that poisoned Victor Yuschenko, and the chemical involved in the northern Italian industrial accident in called the Seveso Disaster are all dioxins. The immediate symptoms of chloracne, can be followed by liver damage, and neuropathy, diabetes and various cancers.
In summary, endocrine disruptors are predominantly the work of mankind. They initially offered great promise in their initial applications, but resulted in great toxicity to the environment and tragic consequences for all who ingested them and who may continue to ingest them. They are so toxic, however, that they have mostly been banned or seriously restricted in use.
Wikipedia, “DDT”
Wikipedia, “PCB”
Wikipedia, “Dioxins”
Wikipedia, “Seviso Disaster”
National Resources Defense Council, “Endocrine Disruptors”
