About Endocrine Disruptors

last updated: September 26, 2011

On the Safer States site, we often mention different chemicals and their role as endocrine disruptors. For instance, bisphenol-a (BPA) and cadmium act as endocrine disruptors in the body. Endocrine disruptors are of concern to the science community because of their ability to wreak havoc on many different biological processes in vulnerable populations. Here's what you need to know about endocrine disruptors:

What are endocrine disruptors?

Endocrine disruptors are chemicals –- both man-made and naturally occurring -- that mimic or block hormones in the endocrine system, interfering with the body's normal regulation of bodily functions. A growing body of evidence is revealing that endocrine disruptors can produce adverse health effects in laboratory animals, wildlife, and humans. Because of this, the issue of endocrine disruptors has become an important public health concern.

What is our endocrine system?

The endocrine system is a complex network of glands, hormones, and receptors that controls important bodily functions. Endocrine glands produce hormones and send them out throughout the body to connect to receptors in organs and tissues and instruct them how to function.

What are endocrine glands and what do they do?

Hypothalamus. Responds to the nervous system and releases hormones to pituitary gland.

Pituitary. Receives signals from the hypothalamus and produces hormones to act on other endocrine glands.

Thyroid. Regulates body growth and development and metabolism.

Adrenal. Produces hormones in response to stress and regulates blood pressure, glucose metabolism, and the body's salt and water balance.

Pancreas. Produces insulin and regulates glucose in the blood.

Ovaries/Testes. Produce steroids that affect growth and development and regulate reproductive cycles and behaviors.

The endocrine system controls all biological processes in our bodies:

• Body growth and development
• Sexual development and reproduction
• Production and utilization of insulin
• Rate of metabolism
• Intelligence and behavior
• Response to stress

How do we become exposed to endocrine disruptors?

We are exposed to endocrine disruptors in much of our everyday life. Synthetic chemicals are found in almost everything we purchase -- food, plastics, toys, furniture, clothing, computers, appliances, pesticides, household cleaners, and cosmetics.

What are the potential health effects of exposure to endocrine disruptors?

While research on human health effects is growing, many chemicals have been found to disrupt the endocrine systems of laboratory animals and wildlife, and research has indicated the following potential health effects:

• Reduced male and female fertility
• Abnormal male reproductive organs
• Early puberty and early reproductive aging in females
• Breast, ovarian, and prostate cancers
• Immune and autoimmune diseases
• Neurodegenerative diseases
• Obesity
• Diabetes

Do you have to be exposed to chemicals in large doses for them to affect your health?

Scientists have long known that even very small naturally occurring changes in hormone levels can affect the body's endocrine system and cause disease. Scientists believe, and research is showing, that even low doses of chemical endocrine disruptors will do the same.

Who is at the greatest risk of health effects from endocrine disruptors?

Fetuses. Research has shown that the greatest risk from endocrine disruptors occurs during the prenatal and early postnatal stages when a fetus is developing organs and neural systems. Endocrine disruptors do cross the placental barrier and even low doses of endocrine disruptors can have significant effects -- health effects that may or may not manifest themselves until the child has reached adulthood.

Children. While fetuses are the most susceptible, growing children are still developing the hormonal relationships that make up their endocrine systems, and are also very much at risk of exposure to endocrine disruptors that may adversely effect them as children or later, as adults.

Pregnant & Lactating Women. Toxins accumulate in adults over a lifetime of exposure and endocrine disruptors in a pregnant woman can be transferred to her fetus or transferred through her milk to her newborn child/toddler.

Adults. As the adult endocrine system is already developed, adults are less at risk from endocrine disruptors than infants, growing children, and pregnant or lactating women, however endocrine disruptors can still cause significant health effects in adults.

What is being done about regulating endocrine disruptors?

In 2009, the Endocrine Disruption Prevention Act was introduced into Congress. The bill was never brought up for a vote, but was updated and re-introduced in 2011. This law would authorize the National Institute for Environmental Health Sciences to conduct research on endocrine disrupting chemicals and their safety. Findings from the research will be passed on to regulatory agencies, giving these agencies the evidence they need to regulate endocrine disruptors and protect the public health.

What can individuals do about exposure to endocrine disruptors?

As we wait for chemical endocrine disruptors to be regulated out of our everyday lives, we can take steps to reduce our exposure to endocrine disruptors. Choosing to remove and stop purchasing or consuming products containing chemical endocrine disruptors can lessen exposure. We can also vote for candidates who will push for strong reform, take action on strong state policies overseeing the chemical industry, and support reform of the Toxic Substances Control Act (TSCA) on the federal level.

Additional Resources

EPA's Endocrine Disruptor Screening Program
The Endocrine Disruption Exchange
National Institute of Environmental Health Sciences
Natural Resources Defense Council
e.hormone
Our Stolen Future