In the blink of an eye, it's already the month of waxing moon, and many readers are already fantasizing about "shopping and eating" for the holidays. However, whether it is shopping or eating, there is one thing that often have to contact the small ticket.
Recently, a media report said that the small ticket or less contact with the good, because the small ticket contains bisphenol A, and bisphenol A can cause cancer.
Related story (Photo credit: Globe)
Is this the truth?
In fact, there are three parts to the question.
First, can BPA cause cancer?
The answer is that it depends.
To determine the toxicity of a substance, there are usually two perspectives, one is emergency toxicity, how much intake at one time will cause poisoning; the second is chronic toxicity, long-term, low-dose exposure, whether it will cause abnormalities in the body.
Bisphenol A (bisphenol A , BPA) is an important chemical raw material, mainly used in the production of epoxy resins and polycarbonate, is widely used in food packaging, medical devices and other fields. Manufacturers produce products in order to earn money, not for lawsuits, and the reason why chemical companies around the world are coincidentally choosing BPA is precisely because Bisphenol A has very low toxicity.
Studies have shown that for rats, the LD50 for BPA is 3250mg/kg.[1] It takes a 50kg adult to drink more than three taels (162.5g) of BPA at a time to be at risk of death. The average person is pressured to worry about it.
It's the chronic toxicity that really concerns people.
No human being can grow or develop without hormones, and for hormones to work, they must bind to the appropriate receptors. When BPA enters the body, it can bind to estrogen receptors, mimicking or even interfering with the effects of estrogen. According to this reasoning, long-term exposure to BPA will cause abnormal hormone metabolism, which in turn will lead to changes in body weight and fetal development; on the other hand, some cancers are hormone-dependent, such as ovarian cancer, which may give BPA a chance to take advantage of. [2]
The structure of BPA
With the increase of corresponding research, governments have attached great importance. The attention is manifested in two ways, by minimizing the chances of introducing BPA to the population, such as the current ban on the use of BPA in bottles in China, and by conducting toxicological studies.
In 2014, the U.S. Food and Drug Administration (FDA) published the results of its own research. The main conclusion was that the human body metabolizes BPA rapidly, and there is no evidence that low doses of BPA are harmful, and likewise there is no evidence that BPA can pass through the placenta, from mother to baby. [3]
FDA's findings (image credit: FDA)
The FDA therefore concludes that it is safe to use BPA in the manufacture of food containers, packaging, etc., and that although a very small amount of BPA precipitates, there is no harm in being exposed to such doses. [4]
The FDA's statement on the safety of BPA (image source: FDA)
So, how much does the so-called "this dose" mean? We can refer to the European Union. The European Food Safety Authority (EFSA) adopted a new standard in January 2015, setting the tolerable daily amount (TDA) for BPA at 4 μg/kgbw/d, which means that a person weighing 50 kilograms who consumes less than 200 μg per day has absolutely nothing to worry about.
Of course some academics were unconvinced, arguing that the FDA's study was too short and flawed. So under the commission of the NIEHS (National Institute of Environmental Health Sciences), the FDA, the National Center for Toxicological Research conducted a long-term study from 2012, and just last year released core data that supported the FDA's conclusions.
Second, do small bills contain BPA?
This is a relatively simple question, and shopping coupons do contain BPA.
Shopping coupons are essentially a type of thermal printing paper. The so-called thermal paper is paper that can develop under heat, and BPA is a common developer. As early as 2010, some scholars tested thermal printing paper, and the results showed that 11 out of 13 samples contained BPA, with levels ranging from 8g/kg to 17g/kg. [5]
Finally, can daily contact with small bills lead to excessive BPA intake?
The amount may seem quite a bit, but unlike a milk bottle, where BPA can go directly into the mouth, BPA on a small ticket can only migrate into the body through the skin, which is much less efficient than the former. The study showed that only about 1 μg of BPA enters the body after holding a small ticket for 5 seconds with dry hands. [5] At this rate, it would mean that touching a small ticket ten times a day would not meet the standards set by the EU.
Of course, less exposure is always better. Keeping your fingers dry is a good way to do this, as dry fingers are less able to absorb BPA, and being willing to wear gloves is naturally more effective.
Additionally, the plastic products you come into contact with in your daily life have abbreviated symbols, consisting of three arrows and numbers (1 to 7), and those with the number 7 may be synthesized from BPA, and there may be a very small amount of BPA precipitation, so you can try to avoid them.
Types of plastic products (image from the Internet)
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References
[1] Liu Yanli, Zhang Yanli. Research progress of bisphenol A in food packaging materials[J]. Food and Machinery, 2011, 27(01): 155-157+174.
[2]Wang Jia, Zhan Ping. Research progress on the effects of bisphenol A on the body and its mechanism[J]. Journal of Preventive Medicine Intelligence, 2005, 21(5): 541544.
[3]NUTRITION C for F S and A. Public Health Focus - Bisphenol A (BPA): Use in Food Contact Application[EB/OL]. [2019-01-24]. . The op-ed articles published on this website represent the views of the authors and are not related to this website. If there is any infringement of copyright, the responsibility of the article will be borne by the author.
Author: Zhao Yancang