The toxic effects of plastics pollution on human health
—Belinda McFadgen, for OEC
In early March of 2019, a Cuvier’s beaked whale washed up dead in the Philippines. The whale had died of gastric shock, brought on by the 88 lbs. of plastic bags found in its stomach.
The sheer volume of plastic waste and its brutal impact on marine wildlife is shocking. But just as disturbing is the emerging story of how the toxicity of plastic pollution is affecting human health and the health of the planet as a whole.
A growing understanding of toxic effects
More than twenty years ago, a health hazard from widespread plastic use made headlines. In 1993, scientists accidentally discovered that polycarbonate plastics leach a chemical that mimics the hormone estrogen. The plastic test tubes they used had contaminated their experiment with bisphenol-A (BPA). At the time, this type of plastic had been on the market for 60 years, and was the favored material for use in baby bottles. Biomonitoring studies have since shown that BPA is present in 93% of humans who have been tested for it.
When marine life is choked by plastic, the cause of death is obvious. But when it comes to chemicals that disrupt hormones, the effects are far more subtle and far-reaching. For example, exposure to a chemical that mimics estrogen can alter puberty, weight regulation, and fertility in children. When a fetus in the womb is exposed, it can interfere with healthy development and increase the child’s risk of cancer later in life. But connecting the dots between one invisible chemical and its impacts on human health is a lot harder than looking at one whale with a stomach full of plastic bags. Instead of proving that BPA is safe before it was widely used, we now spend billions of dollars to better understand just how it is affecting our health.
Over the past 20 years, studies have unearthed solid evidence that plastics leach a variety of chemicals, not just BPA. People can be exposed when these chemicals contaminate our food and drink, and even very small doses can raise the risk of health effects. As for BPA, the chemical was voluntarily removed from materials used to make most baby bottles and sports water bottles. Unfortunately, the other chemicals that replaced BPA have not been adequately tested to ensure that they are safe.
Here to stay
Even if you don’t eat or drink from plastic containers, or buy food packaged in plastic, your health may be affected. We know that instead of breaking down, durable plastics are simply worn down into smaller and smaller pieces.
These tiny plastic pieces continue to release hormone disrupting chemicals like bisphenol A (BPA). What’s more, these plastic fragments attract and absorb other pollutants that are also being washed into our waterways, such as pesticides and industrial waste. Plastics can concentrate contaminants up to 100,000-fold, which makes them the perfect vehicle for transferring contaminants to the human food chain.
A team of scientists, worried about the potential adverse effects of plastics pollution on human reproduction, are currently analyzing samples out in the “Great Pacific Garbage Patch” in the Pacific Ocean. They describe the area as a “plastic soup”; trillions of little bits of broken-down plastic swirling and interacting in a floating plastics graveyard double the size of Texas. So far, microplastics have been found to exist in the guts of fish, but they haven’t been found in the muscle tissue that most people eat.
Smaller is not better
Microplastics, about a fifth of an inch in size, could pass through a human digestive system if ingested. But scientists have more recently discovered that when plastic is washed into waterways and out to sea, the turbulence and heat breaks it down into nano-plastics. These pieces, a microscopic 100 billionth of a meter, are a different story. These particles have the potential to lodge in bodies, penetrate cells, and move into tissues and organs.
What can we do?
Plastic production worldwide doubled between the mid-1970’s and 80s, and doubled again by 2000. Today, we produce 348 million metric tons of plastic a year. Over the past half-century, our world has produced so much plastic that it is measurable on a geologic scale. Geologists from the University of Leicester find that plastic has become a measurable geologic marker on the Earth’s surface.
It’s time to find alternatives that don’t create the problems of toxic exposure and enduring waste. There are efforts to reduce plastic waste by finding alternatives to single-use plastics at restaurants and grocery stores. Recycling processes are being re-examined and ways to clean up the oceans are being explored.
And when it comes to toxic materials, it’s time to stop the expensive, time-consuming, and dangerous practice of introducing chemicals only to find out later that they may cause harm. Instead, we must find alternatives that are proven to be safe before we put them to use by applying the precautionary principle. Plastics have been so useful to us over the last 50 years; innovations in bioplastic demonstrate that we can have the advantages without the incredible toxic cost.
Stay tuned for our next blog in the series, where we will discuss the development of these safer alternatives.