Without a doubt, plastic is a fantastic invention. Without plastics, we would have no snorkels, masks, fins, or other modern scuba equipment, and without plastics, we would still be relying on wood, glass, bone, and other materials for a number of the things that make our lives better and more convenient. Not all plastics, however, are created equally; and, how we handle our own plastic consumption can make a difference. Let’s take a closer look.
What is BPA?
An organic compound that is soluble in organic solvents, Bispehnol A, commonly referred to as BPA, is a colorless solid used to make epoxy resins, polycarbonate polymers, and other compounds that are used to manufacture many plastic-based items.
First synthesized in 1891 by a Russian chemist named Aleksandr P. Dianin, it contains phenol (also known as carbolic acid) and acetone, which is commonly used as paint thinner or nail polish removal. The phenol used in the compound comes from coal tar, and is soluble in water, with approximately 8.3 grams dissolving in 100 milliliters of water. Sodium phenoxide, the sodium salt contained in phenol, is even more water soluble. To synthesize BPA, one unit of acetone is condensed with two equal units of phenol. Hydrochloric acid or another strong acidic compound, like sulfonated polystyrene resin, is then used to catalyze the two components and create BPA molecules.
BPA and its components are very interesting molecules, to say the least. Phenol has been used in medical applications, particularly as an antiseptic although patients’ skin was often irritated by it, and it also saw use during WWII, when it was combined with cyanide and used in lethal injections by Nazis, who administered it as part of their euthanasia program, and as an inexpensive method for killing prisoners held in concentration camps. A single gram of phenol is enough to cause death when injected.
BPA Exposure Risks
Testing has shown that rats exposed to BPA showed changes in prostate and mammary tissue, which suggests an increased potential risk for cancer; in some tests, female mice exposed to BPA experienced accelerated hormonal activity and early puberty. In addition, BPA has been shown to be an endocrine disruptor capable of mimicking the body’s hormones, particularly during early development.
In addition, the substance has been linked to neurological difficulties; particularly when exposure occurs during development. A number of studies conclude that BPA has persistent effects on brain structure and function, affecting the hippocampus and affecting memory processes. A notable study conducted by the Yale School of Medicine showed nonhuman primates who were regularly exposed to the substance at the US Environmental Protection Agency’s maximum safe dose suffered from interference with neural pathways vital to functions including memory, mood, and learning. Another study linked BPA to attention deficit, hyperactivity, and heightened sensitivity to addictive substances.
Altered thyroid function, susceptibility to obesity, increased leukemia, testicular, and breast cancers have all been linked with exposure to BPA; so has neuroblastoma, a particularly aggressive form of brain cancer that tends to affect infants and children. Worse, a 2010 study found that BPA reduced the effects chemotherapy had on some tumors.
BPA Exposure
BPA migrates into food from the epoxy resin coatings that sometimes line the cans products come in, and it also makes its way into water via leaching from polycarbonate plastic bottles. Some pipes used to deliver drinking water are lined with plastic that contains BPA, and Adult exposure is lower than child and infant exposure; and the amount of exposure varies from one person to another.
Since problems with BPA exposure have come to light, popular items such as reusable plastic drinking bottles, baby bottles, kids’ sippy cups, and plastic containers for food storage are being manufactured without BPA; alternatives to plastic are also becoming more popular. Some food manufacturers are now using plastic lined cans that contain no BPA.
BPA and the Ocean Environment
Sadly, BPA has found its way into the ocean and into sand, to the point where it is actually measurable, to the tune of anywhere from .01 to .50 parts per million. During a survey of 200 sites in twenty countries around the world, it and other chemicals found in the plastics that pollute the oceans were found to be ubiquitous; this is not surprising since plastic trash has accumulated to the point where the United Nations estimates that there are around 46,000 pieces of plastic polluting every single square kilometer of the world’s oceans – while we don’t see a lot of it as much is heavily concentrated in gyres, it is there. BPA is also found in wastewater that eventually makes its way into the oceans.
BPA has been shown to cause reproductive disorders in crustaceans and shellfish, and even tiny doses lower than a single part per trillion have been shown to have an effect at the cellular level. Like mercury and other toxins, BPA can bioaccumulate within animals, with greater concentrations occurring up the food chain all the way to top predators, such as sharks, dolphins, seals, and us humans.
While testing on marine organisms has been somewhat limited, test results so far show that BPA can affect the growth and development as well as the reproductive capacity of a number of aquatic organisms including reptiles and amphibians, invertebrates, and fish. A 2011 study conducted in China found that 20 species of freshwater and marine fish collected in a random sampling from markets in Hong Kong did contain measurable levels of BPA.
How to Avoid BPA Plastics
Any product manufactured from hard, transparent plastic probably contains BPA, unless it is specifically labeled “BPA Free.” Some plastics marked with the number “7” in a triangle contain BPA; however, the number seven mark is a kind of recycling catch-all. If the plastic you’re looking at is soft and pliable, it is probably made without BPA. If a plastic item is marked “PC” it contains polycarbonates and is likely to have been manufactured with BPA.
Using metal or glass containers, particularly reusable types, helps you reduce your overall plastic consumption and greatly reduces your risk of exposure to BPA; so does buying fresh or frozen produce instead of canned produce, and so does breast feeding babies or giving them powdered formula rather than formula that comes in liquid form inside plastic-lined cans.
In addition, be careful about microwaving anything plastic, even though it might be labeled as safe to microwave; besides BPA, there could be other chemicals leaching into food since plastic often releases toxins when it is heated. Watch out for bottled water; keep it cool if you drink it, and don’t drink anything that has been left in the sun inside a plastic bottle for a long time.
By selecting plastic products carefully, then re-using and recycling whenever possible, you can make a difference. Be sure to share what you know with others, and you’ll be going the extra mile – not just to protect your own health, but to protect the health of the oceans and the creatures that inhabit them.