On any given day, we engage in countless actions, from simply opening the window in your room when you wake up to washing your face before going to bed at night.
You’re not consistently analyzing every single one of these actions. They take place naturally, with little conscious thought, as your mind often drifts elsewhere.
However, our environments harbor secrets we rarely hear about.
While you might have heard about some of these, such as parabens or phthalates, many of us have not heard of the dozens of others, from nonylphenols to PCBs.
Endocrine Disrupting Compounds (EDCs) are exogenous chemical compounds, or mixtures of chemicals in our external environment, that interfere with the way that hormones function throughout our body.
If you want to hear more info & my thoughts about hormones and their role in our biochemistry, check out my previous article, A glimpse into the world of hormones.
EDCs mimic hormones and can trick receptors into thinking that they are hormones, and block naturally produced hormones from doing their job. This causes the increase or decrease of hormone levels in the blood, affecting the way that they are produced, broken down, stored, and the body’s sensitivity to the hormone.
EDCs can also block cellular responses. Hormones have to bind to their dedicated receptor in order to function. For example, if we have an exogenous, or external, EDC that is structurally similar to estrogen, it binds to the receptor, but it might not activate the receptor. In this case, it just acts as a blocker.
However, there are many different types of hormone blockers. Some EDCs can block the synthesis of certain proteins, which are responsible for the synthesis of hormones. In turn, the natural circulating levels of hormones are altered.
It is important to note that when a chemical compound is released, it has a limited amount of time during which it can carry out its respective actions before they are cleared out of the body. This is the reason why hormonal levels naturally fluctuate. Therefore, if an EDC interferes with the metabolic clearance of hormones, then hormones cannot be properly regulated either.
In general, EDCs can be categorized into two main categories; agonists and antagonists.
Agonists are the hormone mimics, which bind with hormone receptors and continue to initiate a cellular response. While this might not sound like a problem in theory, as we established above, the hormone mimic might not be aligned with the body’s natural and expected hormonal fluctuations (ex. constant secretion of high estrogen) or causes the buildup of naturally produced estrogen in the blood. Antagonists are the blockers, which either stop the hormone receptor, the production of proteins that synthesize hormones, or some other receptor or molecule involved in the secretion or binding of hormones.
EDCs don’t just disrupt a subset of our biological function; they have the capability to alter nearly all of our basic biological processes. According to the Endocrine Society, all hormone-sensitive physiological systems are vulnerable to EDCs. They can cause abnormalities in sex organs, endometriosis, altered function of the nervous system & immune system, cancers, respiratory problems, metabolic issues, growth, neurological and learning disabilities, and much more.
Everything in our body makes a hormone or is sensitive to hormones.
From our muscles, which are especially sensitive to androgens; to adipose tissue, which produces a key hormone called leptin, steroid hormones, and other peptide hormones; to our pituitary gland, which is our master endocrine gland, everything in our body is influenced by hormones.
We are most commonly exposed to EDCs through 3 different routes; ingestion, inhalation, and absorption.
When we are exposed to EDCs in our immediate environment, and in our foods (especially produce), the compounds are potentially absorbed and transferred into the bloodstream where they have the potential to accumulate and affect biological processes.
When inhaled in the form of dust, fragrances, etc., the molecules aggregate in the air sacs within the lungs, are moved to the blood capillaries through the air sacs. Therefore, compounds that are inhaled still have a direct route into the bloodstream, through a much faster transportation system than ingestion. This is the reason why drugs of abuse (marijuana, nicotine, cocaine, etc.) have a much more immediate effect through inhalation than when taken orally.
EDCs can also be absorbed through the skin, which is not good at protecting us from these compounds. Any lacerations, cuts, or lesions allow for easy transport into the bloodstream.
Endocrine Disrupting Compounds
Examples of Common Sources of EDC’s:
- Industrial chemicals infiltrate soil and groundwater in surrounding areas, building up over time and making their way into the food chain
- Pesticide residues on non-organic produce
- Household dust containing lead, flame retardants, and PCB’s from furniture
- Traces of EDC’s accumulated in processed foods from materials used in manufacturing, processing, transportation, and storage
- Consumer and household products, such as cosmetics, certain fabrics, products with fragrance, etc. packaged in containers containing EDC’s
Nonylphenols are surface-active agents or surfactants. They work chemically as a surfactant because of their amphiphilic properties. They have a hydrophilic head that is partially charge and interacts well with the water, and a hydrophobic tail that despises the water. In essence, nonylphenols allow things to be mixed homogeneously, and therefore, are commonly used in detergents, emulsifiers, dyes, and fabric softeners.
Nonylphenols are broadly available, particularly in our clothing. There are some country-specific and variable bans on the use of the surfactant. Because of their broad availability, they end up in our water supply. Even if they are not used in one specific location, chemicals used anywhere in the world can will up in our broader environment. Air and water don’t exactly respect borders.
DDT was a pesticide that was first used in World War II as an insecticide, especially in the Pacific Rim. In order to prevent insect-borne diseases, massive areas would be sprayed with DDT to kill all of the insects in the region, particularly mosquitos.
DDT killed insects by interfering with normal nerve impulses through the opening of neural sodium channels and changes in the electrical charges of the neurons as sodium passes through. This is fatal as neurons communicate through electrochemical connections. Therefore, DDT causes the neurons to spasm and leads to immediate death.
After World War II, DDT was adopted by the agricultural industry, to eliminate pests, which posed a risk to our food production and food chain. When an individual is exposed to DDT, their body has the capability of metabolizing the compound, leading to the formation of a metabolite (metabolic byproduct) called DDE, which stands for the lengthy, 32-letter long name, Dichlorodiphenyldichloroethylene.
While the effects of DDT were first observed in birds by field biologists, such as Rachel Carson, scientists quickly connected the dots, realizing the weak bird eggshells had something to do with this chemical and was likely impacting humans through the food chain.
DDE works as an anti-androgen; it blocks testosterone and other androgens, and induces estrogen-like activity, as it is an exogenous, estrogen-like chemical, known as xenoestrogen.
In essence, DDE impacts the production of sex steroid hormones and can be extremely harmful to fetuses and younger individuals still within developmental stages, within whom DDT can disrupt proper development and reproductive function.
PCBs, or polychlorinated biphenyls, are highly toxic industrial compounds, posing serious health risks to all individuals, but particularly, fetuses, and young children, who have a high risk of suffering developmental and neurological problems just from repeated or high exposure to PCBs.
PCBs were used in a large number of industrial products, before being banned by the United States in 1979. However, PCBs are still present in the air, water, and soil, and are still used in commercial cases, especially in transformers, capacitors, oil in motors and hydraulic systems, old electrical devices, and other electrical equipment.
PCBs were readily used mainly in electrical capacitors pre-1970s as lots of electrical charges needed to pass through dedicated circuits without leaking outside of that path. They are perfect for the job, as they have good insulating properties, barely degrade over time, are chemically stable, and are not flammable.
However, PCBs have, and still continue to be released into large and open natural environments. And the thing about PCBs is that they stay. Especially in closed bodies of water, such as lakes, and other closed environments, the effects of PCBs persist even after decades.
In particular, PCBs can accumulate in the leaves of plants, as well as the bodies of small organisms and fish. As they are one of the most widely studied environmental contaminants, the EPA has concluded that they are probable human carcinogens, alongside significantly impacting an animal’s immune, reproductive, nervous, and endocrine systems. Within the endocrine system, they have resulted in decreased thyroid hormone levels in rodents, as well as developmental deficiencies and other deficits in hearing.
PBDEs, or polybrominated diphenyl ethers, are still widely used EDCs as they were banned in the United States in 2004, Canada in 2008, but are not subject to any restrictions in many other countries, including China.
The variable bans have little impact; the infiltration of PBDEs into the environment impacts all of us in some manner regardless. Furthermore, they are still widely present, even in the United States. Even after being banned over a decade ago, they have been found in many places, including the old light fixtures in New York public schools.
PBDEs are compounds found particularly in textile products; anything from furniture to mattresses, to curtains.
In particular, PBDEs act as flame retardants — preventing the rate at which fire spreads on objects with textile coverings, making homes much safer as the probability of anything from the couch to the carpet spontaneously catching on fire was very high.
As described by the EPA, they are commonly inhaled in our environment. They can also end up in our general surroundings in the form of dust, leaving young children vulnerable to exposure, as they often put their hands in their mouths.
The EPA has also outlined the effects of PBDEs in rats and mice, from neurotoxicity, especially within developmental stages, and impacts on reproductive, thyroid, immune system, liver, and pancreas function, as well as carcinogenic effects.
Phthalates are a group of chemicals, also called plasticizers, that are used to make plastics more durable, and help dissolve other materials. However, they are found in hundreds of products, from vinyl flooring to soaps to meat.
Not only have phthalates been linked to asthma, but they have also been linked to a plethora of disorders and diseases, including ADHD, breast cancer, obesity, Type 2 Diabetes, neurodevelopmental issues, behavioral issues, autism spectrum disorders, impaired fertility, and altered reproductive development.
However, research has shown that fetuses and young children, as well as children in pubertal stages, are at the highest risk. Males are at the highest risk, as phthalates greatly affect male fertility.
Phthalates can be found in the urine of nearly all Americans. In the Fourth National Report on Human Exposure to Environmental Chemicals, CDC scientists measured 13 phthalate metabolites in the urine of over 2,600 participants aged six years and older who took part in the National Health and Nutrition Examination Survey between 2003–2004. Researchers found measurable levels of many phthalate metabolites in the general population, with adult women having higher levels of urinary metabolites than men, for phthalates used in soaps, body washes, shampoos, cosmetics, and other personal care products.
While finding detectable amounts of phthalate metabolites within the urine does not indicate adverse health effects, yet further biomonitoring data will allow scientists to find reference values for what threshold may be harmful.
BPA, or bisphenol A, is an EDC that more individuals are familiar with, due to the negative media attention it has gotten in the past few years, to the labels we often see on canned foods, noting that it is “BPA free.”
BPA is an endocrine disruptor in that it imitates the body’s hormones, particularly, estrogen. In 2013, scientists found that BPA exposure affects egg maturation in humans, and in a 2015 review, found evidence that BPA interferes with endocrine function involving the hypothalamus and the pituitary glands. In essence, BPA proposes impaired reproductive maturation and may affect puberty and ovulation, leading to infertility. Researchers have also noted that the impact of BPA can be “lifelong and transgenerational.” Furthermore, BPA can also influence asthma, breast and prostate cancer, Type 2 Diabetes, heart disease, and fetal brain development.
BPA is a chemical produced in massive quantities, for its use in the production of polycarbonate plastics. Most often, we come into contact with it in the form of plastic bottles, food containers, and the lining of canned foods.
From a utility perspective, hard plastic containers are versatile and practical. However, they pose a widespread concern about BPA. When warm foods or liquids are placed in containers or bottles, such as sippy cups, there is a higher probability of the container leeching BPA outside of the plastic.
According to the CDC, BPA can be detected in practically every single American. At this point, little can be done to reverse the existing BPA toxicity within the country. In both the UK and Canada, there is a widespread BPA ban, while in the US, it is in the hands of states and industries, BPA is banned to a varying extent depending on the state. For example, it is banned in baby bottles and sippy cups in California, but in Vermont, it is also banned in all reusable food and beverage containers.
The EDCs described above are six of dozens. There are all countless types of disrupters, from testosterone blockers to estrogen mimics. But one thing is clear — the chemicals in our immediate environment are much more prevalent than we believe.
In our every waking action, we are surrounded by chemical after chemical.
The chemicals we are exposed to are not in our immediate control. Not all of them, at least. However, there are steps we can take to reduce the exposure we have to endocrine-disrupting compounds, including avoiding plastic containers, using paraben-free and phthalate-free cosmetics, and buying nonpackaged foods whenever possible. While the bounds of our chemical exposure are out of control, focusing on making changes within our daily lives can make all the difference.
Thank you very much for giving this a read! If you learned something from this article, please share it! Be sure to connect with me & see more of my insights on Twitter, check out my personal website, and leave this article a clap if you enjoyed it! 👏
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