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Friday 16 November 2012

Thursday 1 November 2012

"Man, I Feel Like A Woman!" Bisphenol A; The Hormonal Disruptor

What is Bisphenol A?
Bisphenol A (aka BPA) is an organic compound formed by the condensing of acetone with two equivalent amounts of phenol, or carbolic acid. It is colourless, and also without taste nor smell. It was discovered in 1891 by Russian chemist Aleksandr Dianin. One of BPA's earliest uses was in the 1930s when it was used to treat women whom were deficient in estrogen. Many medical fields saw it as an adequate substitute to mimic the female hormone's performance, however it was soon to be superceded by diethylstilbestrol (DES) as a suitable replacement. BPA was also used as a stimulant for physical growth in agricultural animals, most notably cattle and poultry.

Since the 1950s BPA has been largely used as a hardener within the manufacturing of polycarbonate plastics, and found in resins that coat the inside of canned consumable goods. As of 2006, global production of BPA is reported to be in the region of about 3.8 million tonnes, with 66% of it used for polycarbonates, and 30% for epoxy resins. German and American chemical firms Bayer AG and Dow Chemical respectively are two of the largest manufacturers of the substance. Not to be just ingested with food and drink, BPA exposure can occur via breathing in air pollution and dust, and can even be absorbed through the skin. When a material containing BPA is heated, it greatly accelerates the discharge of the compound from its source, this process is known as leaching.

What's so bad about BPA?

Although the material has been used abundantly for decades, concerns over negative side-effects to BPA consumption are much more recent. BPA is an endocrine disruptor, this means that it can "interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife". Mainly because of its strong estrogen-like qualities, various studies show that BPA has integral links to a number of sexual and reproductive dysfunctionalities such as PCOS (PolyCistic Ovarian Syndrome), increased chance of miscarriage, enhanced puberty at a younger than average age, and reduced levels of sperm count. BPA has been regarded by some to be carcinogenic (a key factor in causing cancer) to the breasts and prostrate. Other investigations show connections to a plethora of other problems to arise such as heart disease, diabetes, obesity, and learning disorders including autism, dyslexia and ADHD. Environmentally, plastics containing BPA pollutes the oceans and seas as marine life feed off these misplaced items.

Canada was first to introduce some sort of ban of BPA in foods, prohibiting its usage in baby bottles in 2008. The EU followed suit declaring to do the same in 2010. It has been reported that various other countries are implementing similar restrictions such as China, Malaysia, South Africa and Argentina. Another article mentions that "Japanese canning industry has replaced its BPA resin can liners."

The U.S. government department of the Food and Drug Administration (FDA) approved of Bisphenol A's usage in consumables in the 1960s. Upon rumblings of possible side effects to BPA-exposure growing to a scale that it couldn't feasibly be ignored, the FDA has reviewed their stance towards how safe it is amidst foods in January 2010 and March 2012. Pretty much re-inforcing its initial viewpoints, the FDA still states that BPA in foodstuffs is safe overall, saying that it's "supporting efforts to replace BPA or minimize BPA levels in other food can linings.", however it did eventually follow in the footsteps of its upper neighbouring nation, by also banning BPA featuring in baby bottles earlier this year.

So, what everyday things have Bisphenol A in them?

In 1998, the Society of the Plastics Industry (SPI) introduced a code to separate the varying plastic types for recycling purposes. Ranging from 1 to 9 (but excluding 8), BPA is largely associated to class 7, falling under the polycarbonate family of plastic. It's also likely to be found within class 3 (Polyvinyl Chloride, PVC). Although BPA isn't regarded to be found of a sizable quantity within the other classes of plastics, the SPI doesn't rule out the possibility of BPA being in them. Just to realise the prevalence of BPA, it can be found in many things we use, including;

- Plastic baby bottles and toddler "sippy" juice cups
- Plastic drinks bottles (water, juice, and soft drinks etc.)
- Lining in food cans (tinned vegetables, fish, soups etc.)
- Lining in drinks cans (soft drinks, alcoholic beverages)
- Ready meals in plastic trays
- Plastic food containers (e.g. tupperware; they say safe levels of BPA are in their products)
- Thermal paper from store receipts (e.g. supermarkets, department stores)
- Toilet paper (thermal paper is often recycled to make it)
- Eyewear (it can be present within either or both the plastic used for the lens and the frame), safety goggles
- Compact Discs
- Kids toys (e.g. plastic dolls, plastic ducks for the bath)
- Housings for cellphones, SLR cameras, electrical razors, hairdryers, steam irons, mixers, computers, monitors, TVs, copiers, printers, telephones, microwaves, coffee makers
- Dental sealants/bondings, dental fillings
- Various medical instruments, and packaging for them (e.g. blood oxygenators, dialysers, respirators, syringe tops etc.)
- Blenders/blitzers and food processors
- Sheets for roofing, conservatory glazing, glazing for bus shelters
- Motorbike and cycle helmets
- Mouthpieces for musical instruments (i.e. clarinet, recorder, saxophone etc.)
- Powdered coatings for steel furniture (both domestic and office); also coatings of pipes and fixtures and fittings
- Suitcase shells
- Plugs, sockets and switches
- Automotive bumpers, radiator grills, and dashboards; also waterbourne primer for vehicles
- Printed circuit boards, and electrical components (e.g. transformers, inductors etc.)
- Paper and board varnish, incl. food packaging

Quite an extensive number of items are listed huh? A much more fuller catalogue of examples are given in this PDF made by the European Information Centre on Bisphenol A.

What can I do to reduce my exposure to BPA?
The main thing is to avoid eating out of plastic containers as much as you can. It'd be near-impossible to stop doing so completely, but for example if you drink out of glass bottles instead of plastic, or eat fresh, frozen or dried foods instead of the canned variety, you'd decrease your exposure to BPA. The same goes for cooking food in non-plastic materials - use glass, metals and porcelain where possible. As mentioned earlier, heating up plastics drastically quickens the leaching of BPA out from it into your food. Although there is no official icon or logo, so far, more and more products are displaying themselves as "BPA-free" which definitely makes things easier in one's choice to purchase or not. If you don't need a receipt from a shop for the things you've just bought, don't take it! You're reducing your BPA interaction there too. Below are a few sources that detail what you could do to reduce your intake of BPA:

- "Know Your Plastic Food Containers"
- "Is BPA Making You Fat?" (from Healthy Bitch Daily)
- "17 Surprising Sources of BPA and How to Avoid Them" (from EcoSalon)
- "Are baby bottles toxic? : Bisphenol A"
- eHow Directory on BPA