The harmful effects of bisphenol A (more commonly known as BPA) have been widely publicized lately. It is a known endocrine (hormone)-disruptor and is believed to be associated with an increased risk for a variety of health concerns including cancer, diabetes, cardiovascular disease and reproductive dysfunction. In a troubling new finding, researchers found that a widely used flame retardant that is very similar to BPA also has hormone disrupting ways, just like its chemical cousin.
The flame retardant is TBBPA (tetrabromobisphenol A), and it can be found in a wide variety of products including electrical equipment such as televisions and computers, appliances such as refrigerators, and automobiles. It is released into the environment from these products and ends up in the air, water, wildlife and people. It is currently one of the most widely produced halogenated flame retardants in the world.
TBBPA was already associated with health concerns including possible effects on the immune system and disruption of thyroid hormones. Data from a recent study carried out by the National Toxicology Program (NTP) found that mice and rats exposed to TBBPA can develop tumors, indicating that this chemical is a concern in causing cancer.
As if that wasn’t enough, now a new study carried out by researchers at the National Institutes of Health (NIH) looked at the 3D structure of TBBPA and found that it was able to mimic the estrogen hormone estradiol. Hormones of this type are important for the development of the female reproductive system, along with protection of the heart, brain and bones, and their levels are strictly regulated by the body.
In the normal situation, the levels of hormones like estradiol are regulated by a processing center (known as an enzyme). The estradiol must attach to the processing center in order to be broken down:
Normal Situation: Processing center breaks down estradiol
This study found that TPPBA can attach to the same processing center as estradiol, which could prevent estradiol from binding. If estradiol is unable to bind and be broken down, it could cause a buildup of estrogen in the body:
Excessive amounts of estrogen in the body can lead to a wide-range of health concerns including an increased risk of cancer.
The researchers also looked at the 3D structure of another flame retardant derivative and found that it was able to act in the same way as TBBPA. The ability of different flame retardants to act like this is worrying, as it suggests that an effect on estrogen could occur when different flame retardants are each present at low doses. The effect of multiple low doses of chemicals is usually not taken into consideration when legislation for these chemicals is written, as discussed in a previous blog post.
It is interesting to note that instead of this chemical being withdrawn from the market due to these emerging health concerns, a price increase of 15% has just been announced by Albemarle Corporation.