What it is:
• Hormones are chemicals that act as signaling agents. They are released in one part of an organism, e.g. a cell or organ, and transported to another part where they are recognized by a receptor and bound to the receptor, which results in a biological response.
• There are endogenous hormones, synthetic hormone analogues and also exogenous chemicals (hormone mimics) that can have hormone-like effects from exposure.
• Animals, humans and plants produce endogenous hormones. Plant hormones are called phytohormones.
• There are many types of hormones that serve multiple functions, e.g. estrogens (e.g. estradiol and estrone), androgens, (e.g. testosterone), thyroxine, melatonin, insulin, epinephrine and vitamin D3.
• They can be effective at minute concentrations in the organism. Ethinylestradiol is a synthetic estrogen derivative of 17β estradiol that is widely used in female contraceptives at daily doses of about 10µg.
• Hormones are selective, meaning that a specific chemical structure will bind to the appropriate receptor and result in a specific result. However, some hormones can be effective to some degree across species and some chemicals are structurally similar enough to also bind to some degree.
• Environmental exposures to hormones and hormone mimics are usually very low; although many foods naturally contain phytohormone substances at substantial levels.
• Total dietary intakes of phytohormones can be in the hundreds of mg/day.
• Cereals, fruits, berries and beans, including soybeans, contain substantial amounts of phytoestrogens and many plants and oils contain phytosterols.
• Environmental sources (water) of hormones originate primarily from wastewater that receives natural and synthetic hormones that are excreted by humans.
• Concentrations in wastewater and receiving waters are in parts per trillion (ppt) or parts per billion (ppb) range.
• The potency of a hormone is usually much greater than its mimics.
• There are concerns for the potential for health effects that could be caused by environmental exposures to actual hormones, synthetic hormones or chemical mimics. The latter are often referred to as endocrine disruptors, although a better term would be endocrine active chemicals. Effects have been observed in animals under some environmental conditions.
• Phenolpolyethoxylate detergents have some weak endocrine activity.
• Bisphenol A (BPA) is a phenolic high volume industrial chemical that has major applications in production of epoxy resins that have numerous uses. It has low hormonal activity. There are moves to ban its use in many applications.
• Recently California announced that BPA would be listed under Proposition 65 for reproductive toxicity. The acceptable level is likely to be 0 µg/day, which is much higher than the usual dietary and environmental exposures, and it incorporates 100 to 1,000 safety factor from the animal test data.
• Many hormones are not stable in the environment. The estrogens and androgens are fairly stable and they have attracted much interest because they have been detected at ppt to ppb levels in receiving waters and source waters to some drinking water supplies.
• Feminization of fish has been observed in some receiving waters of sanitary wastewater discharges.
• Conventional drinking water treatment appears to be effective for removing trace amounts of steroidal hormones from drinking water. Other technologies include granular carbon and reverse osmosis.
• Oxidizing disinfectants like chlorine and ozone can chemically react with those hormones and modify their structures assumedly to less biologically active chemicals.
• Potable reuse projects are aware that hormones are present in wastewater and the technologies are very effective at removing them.
• The World Health Organization has reviewed pharmaceuticals, including some hormones and concluded that risks from drinking water exposure are very small and that WHO guidelines are not required.
• USA national regulations for drinking water are under consideration, but it is not known whether there is a likelihood that they will be generated in the near future.
• Several steroidal hormones and some potentially endrogen active synthetic chemicals are listed for monitoring by many drinking water supplies in the U.S. EPA Unregulated Contaminants Monitoring Rule (UCMR 4) that is being developed.
• Some bans for BPA-containing products are under consideration in some states.
Sources: Biochemistry, 3rd Edition. G. Zubay. Wm. C Brown publishers. Pharmaceuticals in Drinking Water, World Health Organization, WHOpharmaceuticals_20110601.pdf. Many foods contain phytoestrogens, Academicsreview.org/reviewed-content/geneticroulette.