As we mentioned before, many xenoestrogens are man made chemicals that have been unintentionally released into the environment over the last 70 years through the industrial and agricultural uses of certain compounds. When introduced into the human endocrine system, through skin absorption or ingestion, these chemicals mimic the effect of the body's natural hormones. They are distinctly different from phytoestrogens, which are naturally occurring substances derived from plant sources.
Xenoestrogens generally fall into one of two categories: pharmacological estrogens, which are specifically developed with a certain purpose in mind, or agents with an unintended and detrimental effect. Compounds that fall into that second category are often difficult to recognize or regulate, for the simple reason that they are not meant to have any effect on the human body at all. Developed for an industrial or agricultural purpose (think pesticides and chemical fertilizers), their effects on human beings are a corollary, and until recently unrecognized, danger.
First, to the sources: When I mention that Xenoestrogens are ubiquitous, I mean they are truly everywhere. These compounds can be absorbed into the human body through the skin, inhaled, or ingested, and we unknowingly do so throughout our daily lives. As we have already discussed, many plastics pass estrogenic chemicals into our environment, particularly when they are cut or heated. While most of us immediately think of plastic water bottles and BPAs, the complete saturation of our environment with plastics is taken for granted far more than it ever should be.
Plastics are not, however, the only source of estrogenic compounds. Chillingly, some of our food sources may be just as dangerous as the packaging they are shipped in. American-grown, non-organic livestock are often fed estrogenic hormones in order to fatten them up, and they consume feed that is laden with chemical pesticide sprays before they are processed. While "free-range" and "grass-fed" have become effective advertising terms that have gained traction in supermarkets, the reality is that many of these sources are still laden with chemicals that promote endocrine disruption in one form or another.
We've also discussed on this blog how certain cosmetics are often filled with harmful chemical compounds. Phthalates, which are commonly found in fingernail polish and glues, are endocrine disruptors, and can particularly interfere with male sex hormones. Emulsifying chemicals are increasingly troubling as well; found in soaps and shampoos, they are easily transferred across the membranes of the skin.
The sources of xenoestrogens don't end at the supermarket doors, however, and they often enter our environment from even more unusual sources. Car exhaust, for example, is a real issue for a number of health problems, and people who live in urban areas or regions where they are constantly exposed are breathing in harsh chemicals that have effects far beyond damage to the respiratory system.
Pesticides are yet another major source of chemical contamination, and we are exposed to them on a daily basis, though we often take it for granted. Most supermarket produce has been treated with pesticides at some point and contains residual traces of contamination. Pesticides that are washed off of produce can go on to contaminate groundwater sources. Synthetic estrogens used in oral contraceptives and hormone replacement therapies can also contaminate water sources as many are passed out of the body through urine.
While most water treatment plants have implemented systems for addressing chemicals such as xenohormones, incomplete removal can allow endocrine disrupting compounds to pass into the environment. Industrial waste products, like polychlorinated biphenyls (PCBs) and dioxins, can also contaminate waterways, and lest we forget, what contaminates our water is found in fish as well. Supermarket to river...the circle of life (If by life you mean chemicals).
While the list of potential sources seems shockingly universal, the reason that xenoestrogen contamination goes unnoticed by society at large is that the levels encountered over the short term are very slight. Once in the human body, however, these chemicals build up, causing long term damage that compounds over time. Chemicals can also interact with one another while in our bodies, leading to a host of other unpredictable ill-effects.
The health consequences of xenoestrogens are an extremely broad and deep topic, one that deserves close attention. To that end, I've decided to split this post in two, and will continue with more far more details on the effects of estrogenic chemical compounds, and what you can do to avoid them, in our next post.