The average American produces a half-pound of plastic waste every day; while around the world, 300 million tons of the exceedingly durable material are produced each year. Plastics were the material pegged to change the world; and they have had an amazing impact. But for all the technology and convenience borne from the polymer family, untold perils are becoming realized as well. Just how dangerous are plastics for human and environmental health?
Wading through the confusing studies, many sponsored by those with financial interests in the material, has been a daunting proposition. So hats off to Rolf Halden, associate professor in the School of Sustainable Engineering at Arizona State University and assistant director of Environmental Biotechnology at the Biodesign Institute. Halden has undertaken a survey of existing scientific literature concerning the hazards of plastics to human health and to the ecosystems we depend on. His findings, which appear in the latest issue of the Annual Review of Public Health, his conclusions are pretty grim.
Because of the material’s longevity, plastics pile up in landfills and are occupying the world’s oceans in increasing quantity. Halden’s study reiterates the fact that the effects to the environment from plastic waste are severe. Measurements from the most contaminated regions of the world’s oceans show that the mass of plastics exceeds that of plankton sixfold. Patches of oceanic garbage, called gyres, are swirling vortexes of plastic bits. The North Pacific Gyre, one of several in the world, is expanding at such a rate that from the first time it was studied until now, it has grown from the size of the state of Texas to twice the size of the continental United States!
Aquatic birds and fish routinely becomes victims because although plastic does undergo some biodegradation, it doesn’t thoroughly break down. And plastics and their additives aren’t just present in our environment, virtually all of us ingest them as well; plastic is consumed with the food we eat, the water we drink and from other sources.
As Halden points out, annual production alone would fill a series of train cars encircling the globe. “We’re doomed to live with yesterday’s plastic pollution and we are exacerbating the situation with each day of unchanged behavior,” he said.
Two classes of chemicals from plastic are of serious concern for human health: bisphenol-A or BPA, and additives used in the synthesis of plastics, which are known as phthalates. BPA is a basic building block of polycarbonate plastics, such as those used for bottled water, food packaging and other items. BPA is a synthetic estrogen and commonly used to strengthen plastic and line food cans. Scientists have linked it, though not conclusively, to everything from breast cancer to obesity, from attention deficit disorder to genital abnormalities in boys and girls alike.
Adding to the health risks associated with BPA is the fact that other ingredients are routinely added to plastics. Many of these potentially toxic components also can leach out over time. Among the most common is a chemical known as di-ethylhexyl phthalate or DEHP. In some products, like medical devices including IV bags or tubing, additives like DEHP can comprise nearly half of the of the product. “If you’re in a hospital, hooked up to an IV drip,” Halden explains, “the chemical that oozes out goes directly into your bloodstream, with no opportunity for detoxification in the gut. This can lead to unhealthy exposure levels, particularly in susceptible populations such as newborns.”
Halden explains that although plastics have some beneficial and legitimate uses in society, their thoughtless misuse has led to a gravely unsustainable condition. “Today, there’s a complete mismatch between the useful lifespan of the products we consume and their persistence in the environment.” Prominent examples of offending products include single-use water bottles, Teflon-coated dental floss and cotton swabs made with plastic PVC sticks. All are typically used for seconds or minutes, yet will persist in the environment, sometimes for millennia.
Ultimately, developing petroleum-free materials for use in smart and sustainable plastics will become a necessity, driven not only by health and environmental concerns but by the world’s steadily declining oil supply. As Halden emphasizes, the manufacture of plastics currently accounts for about 8 percent of the world’s petroleum use, a sizeable chunk, which ultimately contributes to another global concern — the accumulation of carbon dioxide in the atmosphere.
“We are at a critical juncture,” Halden notes, “and cannot continue under the modus that has been established. If we’re smart, we’ll look for replacement materials, so that we don’t have this mismatch–good for a minute and contaminating for 10,000 years.”