6 May, 2016
What is wrong with BPA?
We live in a toxic world and our children are being exposed to far more environmental chemicals than we were when we were young. The more you know about these toxins, the scarier life becomes. We wonder how we can protect our children from being poisoned and we make decisions to reduce their exposure, for example by not using pesticides, buying organic food and avoiding plastic in the kitchen and the playroom. And then well-meaning relatives or friends tell us off for being neurotic and over-protective. That is when you need to be well informed, so you can explain why you make these choices. There is plenty of research published about the effects of environmental toxins on children’s health and development. In this article I will focus on BPA in plastics. Why is it so bad? What does it do to our bodies and brains? And to the environment?
BPA (Bisphenol A) is one of the most pervasive chemicals– everyone has heard of it and almost everyone (>95% of the population) has some of it in their body. 50 billion pounds are produced every year. It is found in countless consumer products from food packaging, to toys, the lining of food cans, hard plastic bottles, thermal receipt/eftpos paper and receipts – it is also found in hospitals: medical equipment, such as PVC plastic tubes contain BPA to make it less brittle and many premature babies are exposed to it while they are in intensive care nurseries.
Hard plastics contain bisphenols to make them less brittle. There are more than a thousand studies on their effects. I find it interesting that 100% of the studies funded by the plastics industry found BPA to be be safe for humans while 99% of the more than 1000 independently funded studies (mostly in animals) and over 80 epidemiological studies in humans found that it is toxic even in tiny amounts; in particular, it affects our hormones by disrupting our endocrine system. BPA acts like a hormonal drug and binds to oestrogen receptors and stimulates an oestrogen-like response. At higher doses it will also stimulate receptors for other hormones through what is called “receptor cross talk”: it can stimulate thyroid hormone receptors, testosterone receptors, and receptors that mediate fat cell generation. The thing about endocrine disruptors is that they are toxic even in minute amounts – as little as 1 part per trillion. One explanation for this is that BPA does not bind to human plasma hormone binding proteins (which generally make hormones less active). As opposed to other poisons there is no safe threshold with endocrine disruptors. Exposure to 1 part per trillion during pregnancy can cause male foetuses’ reproductive systems to develop abnormally, for example leading to hypospadias (when the urethra, the opening through which urine flows, is on the base rather than at the end of the penis).
BPA interferes with the development of sperm cells and with normal prostate development (potentially affecting fertility and increasing the risk of prostate cancer later in life). BPA is also very damaging to egg cells and affects the success of in vitro fertilization: the higher the BPA in a woman’s body, the lower the chance of a successful pregnancy – the chemical influences the quality of the sperm cells, egg cell and eventually the embryo. Harm caused by BPA in pregnant mothers at levels that the average US population is exposed to (exposure in Australia and New Zealand is similar) include ADHD-type behaviour changes in their children: learning problems, reduced attention and an increase in aggressive behaviour; it is also associated with increased anxiety in children.
The risk of metabolic disease, which includes diabetes, high blood pressure and heart disease, is affected by BPA levels. Metabolic disease is the number one health crisis in developed countries – a precursor to two of the most common cause of death: heart disease and stroke. In one recent Korean study drinking the contents of just two BPA-lined cans increased the blood pressure in adults immediately and increased the BPA in the urine 16-fold compared to people who drank from glass bottles.
BPA has also been found in breast cancer cells – it is considered a carcinogen and this effect starts in utero when the mammary glands (or breast tissue) develops. It leads to an increased risk of cancer (another common cause of disease and death).
Given all this information, it becomes clear that we should try and avoid BPA – from before birth until adulthood. Is this possible?
BPA is excreted in the urine and is released into the environment. Thousands of pounds of BPA are released into the air from industrial smoke stacks and then settles into streams near these factories. It also leaches from plastic in landfills into ground water. It is such a small molecule that it does not get filtered out of the water in waste treatment plants.
So once the BPA is released into the environment, it enters a cycle from which we cannot easily escape. Luckily the half-life is relatively short – several weeks or months, so it does not persist in the environment (as many other toxins do). The other good news is that carbon filters filter out BPA from water.
In summary BPA is not safe; it affects our hormone balance, increases the risk of metabolic disease, is a carcinogen and a developmental toxin. The toxic effects can even last for several generations, as they are imprinted into our genes.
Due to consumer demand (and in more progressive countries due to regulations) many manufacturers have started to produce BPA-free containers, bottles and cans. So you can now buy BPA free plastic water bottles, baby bottles, – but are they any safer? In fact the producers simply replaced BPA with other plasticizers, such as BPS. Research indicates that BPS may be even more toxic than BPA, we just have not had a chance to study it in depth. I would not be surprised if in a few years, BPS was banned.
So what can you do to avoid BPA and other plasticizers?
Replace plastic food containers, lunch boxes, and plastic water bottles/baby bottles with glass or stainless steel. It has become easier to find glass containers: even Ikea sells them. N
Do not buy canned foods, especially cans containing anything acidic, such as tomatoes, as the acid increases the BPA amount leaking into the food.
Do not buy “BPA free” plastic – as these contain other plasticisers, such as BPS, which may be just as toxic as BPA but has not been studied as extensively.
Replace plastic toys with untreated wooden ones.
Do not touch thermal coated receipts – they are coated with BPA. Never let your children play with thermal coated paper.
Use a carbon filter for your water at home – this will filter out BPA from your water.
If you do all of the above, you will reduce your family’s exposure to BPA and other plasticizers. And this may hopefully lead to a healthier life for everyone, over many generations.
Written by Dr Leila Masson, Pediatrician.
Bisphenol A exposure and children’s behavior: A systematic review. J Expo Sci Environ Epidemiol. 2016 Mar 9. doi: 10.1038/jes.2016.8. [Epub ahead of print]
Chen D, Kannan K, Tan H, Zheng ZG, Feng YL, Wu Y, Widelka M. Bisphenol Analogues Other Than BPA: Environmental Occurrence, Human Exposure, and Toxicity – A Review. Environ Sci Technol. 2016 May 4. [Epub ahead of print]
vom Saal FS, Hughes C. An extensive new literature concerning low-dose effects of bisphenol A shows the need for a new risk assessment. Environ Health Perspect. 2005 Aug;113(8):926-33.