World - The Many Lifetimes of Plastics
Many of us have seen informational posters at parks or aquariums specifying how long plastics bags, bottles, and other products last in the environment. They're a good reminder to not litter, but where does the information on the lifetime expectancy of plastic goods come from, and how reliable is it?
It turns out, getting a true read on how long it takes for plastic to break down in the environment is tricky business, says Collin Ward, a marine chemist at Woods Hole Oceanographic Institution and member of the its Microplastics Catalyst Program, a long-term research program on plastics in the ocean.
"Plastics are everywhere, but one of the most pressing questions is how long plastics last in the environment," he says. "The environmental and human health risks associated with something that lasts one year in the environment, versus the same thing that lasts 500 years, are completely different."
Knowing the fate of plastics may be tricky, but it's critical. Consumers need the information to make good, sustainable decisions; scientists need it to understand the fate of plastics in the environment and assess associated health risks; and legislators need it to make well-informed decisions around plastic bans.
The long-standing mystery around the life expectancy of plastic goods has prompted a new study from Woods Hole Oceanographic Institution looking at how the lifetime estimates of straws, cups, bags, and other products are being communicated to the public via infographics. Ward, the lead author of a new paper published in the journal Proceedings of the National Academy of Sciences, along with WHOI marine chemist Chris Reddy, analyzed nearly 60 individual infographics and documents from a variety of sources, including governmental agencies, non-profits, textbooks, and social media sites. To their surprise, there was little consistency in the lifetime estimates numbers reported for many everyday products, like plastic bags, among the materials.