Their work revealed several important findings, including that the majority of this garbage comes from toxic plastics. They say unless consumers are disposing of it, this litter will likely remain in the environment forever.
“There has been a lot of emphasis on individual human behavior as the way to decrease rates of littering,” said researcher Andrew Gray. “In reality, it’s just as easy or even more accurate to say that if we didn’t produce the stuff in the first place, it wouldn’t get into the environment.”
Understanding trends in littering
For the study, the researchers analyzed nearly 3,300 feet of roadside several times per week for a month in five cities across southern California: Riverside, San Dimas, Moreno Valley, Palm Desert, and Loma Linda. Their analysis was primarily concerned with the accumulation rate of the litter, the origin of the litter, and the composition of the roadside litter.
Ultimately, 60% of all roadside trash they collected was plastic, and most of it was either food or tobacco products. The study also showed that much of this trash doesn’t travel very far; consumers are depositing it along the road just short distances from wherever they purchased it.
“A lot of people say, ‘it’s not my trash,’” said researcher Win Cowger. “I want to dispel that notion with the evidence that we have, at least here in the Inland Empire.”
The researchers explained that while roadside litter may not seem like a significant issue, when left unattended, it remains in the environment forever. This means that these plastic and paper products eventually end up as pollution in the air or the water, or it breaks down into microplastics that are later ingested by consumers.
Finding solutions for littering
With a better understanding of how roadside littering happens and what the primary culprits are, the researchers are now looking to find tangible ways to fix this issue. Their work showed that simply cleaning up roadside litter isn’t enough; in the team’s daily roadside inspections, they cleaned up the sites only to find there was more litter the next day.
“There’s a broken window theory some people subscribe to, that trash begets trash,” said Coger. “However, we find even if you keep a place clean the accumulation is really consistent so other actions to prevent litter in the first place are needed.”
The researchers now plan to conduct similar trials across the country, and they’re calling on public officials to step in and ramp up efforts like street cleaning for the overall benefit of the environment.
“There’s a more systematic approach we need to take as humans to decide what gets produced, because eventually, it all gets into the environment,” said Gray.