The Effects of Plastic on the Environment

From cell phones and computers to bicycle helmets and hospital IV bags, plastic has molded society in many ways that make life both easier and safer. But the synthetic material has also left harmful imprints on the environment and perhaps human health, according to a new compilation of articles authored by scientists from around the world. More than 60 scientists contributed to the new report, which aims to present the first comprehensive review of the impact of plastics on the environment and human health, and offer possible solutions.

As the scrutiny of the environmental toll of plastic increases, so has its usage, the scientists reported. Since its mass production began in the 1940s, plastic’s wide range of unique properties has propelled it to an essential status in society. Next year, more than 300 million tons will be produced worldwide. The amount of plastic manufactured in the first ten years of this century will approach the total produced in the entire last century, according to the report.

Evidence is mounting that the chemical building blocks that make plastics so versatile are the same components that might harm people and the environment. And its production and disposal contribute to an array of environmental problems, too. For example:

• Chemicals added to plastics are absorbed by human bodies. Some of these compounds have been found to alter hormones or have other potential human health effects.
• Plastic debris, laced with chemicals and often ingested by marine animals, can injure or poison wildlife.
• Floating plastic waste, which can survive for thousands of years in water, serves as mini transportation devices for invasive species, disrupting habitats.
• Plastic buried deep in landfills can leach harmful chemicals that spread into groundwater.
• Around 4 percent of world oil production is used as a feedstock to make plastics, and a similar amount is consumed as energy in the process.

People are exposed to chemicals from plastic multiple times per day through the air, dust, water, food and use of consumer products. For example, phthalates are used as plasticizers in the manufacture of vinyl flooring and wall coverings, food packaging and medical devices. Eight out of every ten babies, and nearly all adults, have measurable levels of phthalates in their bodies.

In addition, bisphenol A (BPA), found in polycarbonate bottles and the linings of food and beverage cans, can leach into food and drinks. The U.S. Centers for Disease Control and Prevention reported that 93 percent of people had detectable levels of BPA in their urine. The report noted that the high exposure of premature infants in neonatal intensive care units to both BPA and phthalates is of “great concern.”

Polybrominated diphenyl ethers or PBDEs, which are flame-retardants added to polyurethane foam furniture cushions, mattresses, carpet pads and automobile seats, also are widespread. The plastics industry maintains that its products are safe after decades of testing. But some of these chemicals have been shown to affect reproduction and development in animal studies, according to the report. Some studies also have linked these chemicals with adverse effects in people, including reproductive abnormalities.

Shanna Swan, director of the University of Rochester’s Center for Reproductive Epidemiology, conducted studies that found an association between pregnant women’s exposure to phthalates and altered genital development in their baby boys. Also, people with the highest exposure to BPA have an increased rate of heart disease and diabetes, according to one recent study. Animal tests studies of PBDEs have revealed the potential for damaging the developing brain and the reproductive system. Yet the effects on human health remain largely unknown. To help shed more light on the issue, the report recommends more sophisticated human studies.

Plastic’s problems extend beyond the human body, according to the report. More than one-third of all plastic is disposable packaging like bottles and bags, many of which end up littering the environment. Although the image of a bird tangled in a plastic necklace is by now burned into the public’s eye, ingestion of plastic fragments is much more common. Once inside, plastic can pack a one-two punch by both clogging an animal’s stomach and poisoning it with chemicals that have concentrated in the plastic. Some chemicals are then transferred to the food web when animals eat them.

More than 180 species of animals have been documented to ingest plastic debris, including birds, fish, turtles and marine mammals, according to the report. Unfortunately, collecting data on plasticizers’ impacts on wildlife suffers the same pitfalls as studying human health. Still, there is already evidence that chemicals associated plastics might harm wildlife. For example, laboratory studies have shown that phthalates and BPA affect reproduction in all studied animal groups and impair development in crustaceans and amphibians.

Traveling from coast to coast, plastic can endure for thousands of years due to the reduced UV exposure and lower temperatures of aquatic habitats. Plastic also serves as a floating transportation device that allows alien species to hitchhike to unfamiliar parts of the world, threatening biodiversity. Global warming further aids the process by making previously inhospitable areas like the Arctic livable for invasive species, which can be detrimental to local species. For example, plastic items are commonly colonized by barnacles, tubeworms and algae. Along the shore of Adelaide Island, west of the Antarctic Peninsula, ten species of invertebrates were found attached to plastic strapping that was littering the ice.

Plastic is so resilient that even burying it deep within the earth doesn’t keep it from impacting the environments. Currently it accounts for approximately 10 percent of generated waste, most of which is landfilled. But, as the report notes, placing plastics in a landfill may simply be storing a problem for the future, as plastic’s chemicals often sink into nearby land, contaminating groundwater. In addition, production of plastics is a major user of fossil fuels. Eight percent of world oil production goes to manufacturing plastics.

As plastics grow in volume at a rate of about nine percent each year, the authors emphasize that tackling its problems means addressing its sustainability. One solution is to treat plastic as a reusable material rather than as a disposable commodity that’s quickly discarded. That means making plastic more easily recyclable from the get-go by using fewer materials in the manufacturing process and increasing recycling facility availability. Increasing the availability of biodegradable plastic, which can be made from renewable materials from plants such as corn and soy, is another option.

The authors said that if plastics are made and used responsibly, they can help solve some environmental problems. For example, one study found that packaging beverages in PET (a type of plastic) versus glass or metal reduces energy use by 52 percent and greenhouse gas emissions by 55 percent. And, solar water heaters containing plastics can provide up to two-thirds of a household’s annual hot water demand, reducing energy consumption.