Endocrine disruptors are chemicals that disturb the processes controlled by the endocrine system. These synthetic or natural chemicals can affect a person by being inhaled, ingested or through touch. The different types of endocrine disruptors include the DDT insecticide, Bisphenol A (BPA), alkylphenols, phthalates and Polybrominated Diphenyl Ethers (PBDEs).
The endocrine system contains a large number of glands in the body that produce hormones. The ovaries, testes, pituitary, adrenal, thyroid and parathyroid are all glands that make up the endocrine system. These glands are involved in and essential for many important body processes, including reproduction, electrolyte balance, growth and energy production and storage. They produce hormones such as insulin, estrogen, adrenaline, adrenocorticotropic hormone (ACTH), antidiuretic hormone (ADH) and the thyroid hormone. When the production of any one of these hormones is disrupted, the delicate balance of the body is put at risk and multiple processes and organs can be affected.
Endocrine disruptors can be harmful in numerous ways. They can imitate the hormone, block the hormone from binding to its receptor, or they can disrupt the process of a hormone binding to a receptor. Each of these can cause the hormones to send incorrect signals to the glands, which could either over-produce or under-produce the hormone, depending on how the disruptor has affected the cells.
DDT used to be used an insecticide; it was banned internationally in 2001 by the Stockholm Convention on Persistent Organic Pollutants treaty. DDT became a popular substance during World War II to prevent typhus, dysentery and typhoid, and once the war was over, it became a popular insecticide for use on crops. Subsequent studies found, however, that DDT can harm the reproductive health of females and males. DDT also was found in paints, paper, insulation materials and oil.
Bisphenol A is contained in polycarbonate plastics, such as food containers and baby bottles. It also is contained in the lining of canned foods, dental materials, nail polish and even eye glasses. Both Bisphenol A and alkylphenol act as endocrine disruptors by imitating the estrogen hormone. Some alkylphenols are found in detergents, cosmetics and foaming products.
Phthalates are endocrine disruptors that are found in soft plastics, cosmetics, glues and air fresheners. Research has shown some phthalates to be involved in damaging the reproductive health of males. PBDEs also may affect reproduction, causing birth defects or learning disorders in infants who were exposed to the chemical. They also are known for damaging the production of the thyroid hormone. These chemicals commonly are found in flame retardant materials.