Chemical Exposures and Our Endocrine System
The human endocrine system produces hormones that help regulate bodily functions, including metabolism, growth, development, tissue function, sexual function, reproduction, sleep and mood. Made up of the pituitary, thyroid, parathyroid and adrenal glands, as well as the pancreas, ovaries (in females) and testicles (in males), the endocrine system is at work virtually all the time. Our bodies rely on hormones to manage many normal daily functions, as well as ongoing growth and developmental changes throughout our lives.
Given the importance of endocrine activity to our overall health, it’s understandable that readers may become concerned by posts on popular social media sites that claim exposures to some chemicals may have lasting health impacts on their body.
The terms “endocrine-disrupting chemical” or “hormone-disrupting chemical” are widely misused and considered by scientists to be a misnomer, since many substances have been shown to interact with the endocrine system without causing an adverse health effect. Many things we come in contact with, such as sunlight, or common substances, such as caffeine, can “activate” the endocrine system. Some of these interactions are harmless. Others are helpful — like when exposure to sunlight causes our bodies to produce Vitamin D.
What is an endocrine disruptor?
In order for a chemical to be an “endocrine disruptor,” it must affect the endocrine system in a way that causes a negative health effect. It’s important to distinguish endocrine activity that is disruptive or damaging, from endocrine activity that is neutral or even essential to our well-being.
Not all chemicals that interact with the endocrine system present a risk of harm – in many instances, the body naturally adjusts and there is no health effect. For example, when we drink a soy latte or eat edamame, our estrogen levels will become slightly elevated, and then return to normal after a short time. Just because a substance is endocrine active does not mean that it is endocrine disruptive.
So how do we look beyond the headlines, to understand the science? Some chemicals, both natural and man-made, can and do interact with the endocrine system. There is confusion as to whether this interaction is itself harmful, or if the endocrine activity could lead to harm if exposure is above a certain level or frequency.
The two articles on the right explore 1) the science of how our bodies are exposed to and metabolize substances, as well as 2) public policy developments – how government regulators study and screen substances to understand if they might be endocrine active or endocrine disrupting.
The goal is to enable regulators to use science to reasonably assess real-life risk – the possibility of harm arising from a particular exposure to a specific chemical, under typical conditions. In doing so, scientists can help provide informed and confident recommendations to regulatory decision-makers about how chemical ingredients can be safely used as a part the products and materials in our everyday lives.