Friday, March 3, 2017
Replacement Chemical In BPA-Free Bottles Also Disrupts Estrogen In The Body
BPA, or bisphenol A, is often found in disposable water bottles and babies' milk bottles and cups. Small amounts can dissolve into the food and drink inside these containers. It is a dangerous chemical linked to health concerns from digestive problems to issues with brain development. It was previously found present in around two billion products in the U.S. that were used on a daily basis.
By 2009 it had the highest production volume and use in consumer goods, with 2.2 million tons consumed globally.
Because it's the most harmful on developing brains and bodies, children and pregnant women, it started to be phased out from the manufacturing process of plastics.
This is a concern because a host of studies have shown that BPA can mimic the actions of oestrogen, binding to the same receptor in the body. Oestrogen is normally involved in breast development, regulating periods and maintaining pregnancies. Animals exposed to BPA develop abnormal reproductive systems, but it is unclear if people are exposed to high enough doses to be affected.
Due to public pressure -- and bans in a few countries -- many manufacturers have started replacing BPA. However, recent investigations have shown that Bisphenol A isn't the only endocrine disrupting chemical consumers should be worried about. According to an article published in the US News and World Report, chemical substitute BPS, an endocrine disrupting hormone with traits very similar to BPA, is present in BPA-Free products and is inside paper money, cash register receipts and most plastic consumer products much like its predecessor.
Widespread human exposure to BPS was confirmed in a 2012 analysis of urine samples taken in the U.S., Japan, China and five other Asian countries.
BPS has some of the same estrogen-mimicking effects of BPA, and that people may now be absorbing 19 times more BPS through their skin than when BPA was used to coat paper.
Not only does BPS appear to have similar hormone-mimicking characteristics to BPA, but research suggests it is actually significantly less biodegradable, and more heat-stable and photo-resistant, than BPA.
Another substitute, fluorene-9-bisphenol, or BHPF, is already widely used in a variety of materials. But Jianying Hu of Peking University in Beijing and her team have found that BHPF also binds to the body’s oestrogen receptors. Unlike BPA, it does this without stimulating them, instead blocking their normal activity. In tests on female mice, BHPF caused the animals to have smaller wombs and smaller pups than controls, and in some cases miscarriages.
In recent years, BHPF has shown up in all sorts of adhesives and plastic materials--everywhere from the aerospace and automobile industry to coatings used to protect floors. "So we are interested in the human exposure and risk due to the usage of BHPF," Hu said.
A 2012 World Health report noted that “significant knowledge gaps exist on the association between exposure to endocrine-disrupting chemicals and adverse pregnancy outcomes, even though the incidence of these outcomes, such as spontaneous abortion, stillbirth, low birth weight and fetal death, has increased in many countries over the last decades.”
And those knowledge gaps leave many concerned.
But none of this matters if we're not coming into contact with BHFP it's only a potential problem if humans are exposed to it. To see if we are being exposed, Hu and his colleagues tested 100 students for the presence of BHFP. Seven percent of them tested positive for the chemical. The testing wasn’t done to prove that BHFP is harming human health, but rather serves to suggest that at least some of us are being potentially exposed to it and that we need to look deeper into what this might mean. How dangerous might BHFP be, and how is it getting into our bodies?
We have some clues about the latter question: because BPA rose to such prominence due to its use in plastic drinking bottles, and because a lot of Chinese students drink boiled water out of plastic water bottles, Hu's team tested polycarbonate bottles both baby bottles (polycarbonate baby bottles are banned in China, so they had to purchase them from abroad) and adult drinking water bottles for the presence for BHPF. They found that water samples taken from all three baby bottles tested positive for BHPF.
Similarly, they detected BHPF in water from two bottles made of Eastman Tritan's BPA-free copolyester. It's unclear if the bottles Hu tested are available in the United States. But the U.S. might not be regulating the use of BHPF at all. A survey of three FDA databases--Indirect Additives used in Food Contact Substances, Inventory of Effective Food Contact Substance (FCS) Notifications, and the Threshold of Regulation (TOR) Exemptions failed to turn up references to either Fluorene-9-bisphenol or BHPF. If the FDA has deemed BHPF safe to use, it should show up in one of those databases.