By Jessica A. Knoblauch
Environmental Health News
July 2, 2009
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 also has 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.
“One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics,” wrote David Barnes, a lead author and researcher for the British Antarctic Survey. The report was published this month in a theme issue of Philosophical Transactions of The Royal Society B, a scientific journal.
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.
“Plastics are very long-lived products that could potentially have service over decades, and yet our main use of these lightweight, inexpensive materials are as single-use items that will go to the garbage dump within a year, where they’ll persist for centuries,” Richard Thompson, lead editor of the report, said in an interview.
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.
“Every additive that we use is very carefully evaluated, not just by the industry, but also independently by government agencies to look at all the materials we use in plastics,” said Mike Neal, a consumer and environmental affairs specialist at PlasticsEurope, an industry trade association, and a co-author of the report.
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.
“We have animal literature, which shows direct links between exposure and adverse health outcomes, the limited human studies, and the fact that 90 to 100 percent of the population has measurable levels of these compounds in their bodies,” said John Meeker, an assistant professor of environmental health sciences at the University of Michigan School of Public Health and a lead author. “You take the whole picture and it does raise concerns, but more research is needed.”
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.
“It’s tough to have a smoking gun with a single animal study or observational human study,” Meeker said. “We need to have different types of studies indicating a consistent pattern to more definitively determine health effects resulting from these chemicals.”
A sea of plastic: Shocking images show how bottles, bags and rubbish are choking our oceans.
These pictures are unlikely to make it into the glossy tourist brochures that sell the Caribbean as a paradise destination.
For they show the much grimmer reality of clear blue seas increasingly choked by a tide of discarded plastic.
In one photograph taken near Roatan, an island off the coast of Honduras, a diver grimaces as he prepares to enter the water almost completely covered by waste.
Another, taken from below the waterline, shows plastic bottles, bags and other rubbish on the surface blocking out sunlight.
Meanwhile, a close-up image of the ocean reveals dozens of disposable knives and forks floating among seaweed.
It is thought the rubbish was washed into the sea from nearby Guatemala, carried on rivers swollen by the recent rainy season flowing through towns and villages.