For the study, researchers from the University of California, Riverside spent a month collecting trash from seven sites across the Inland Empire. They examined its composition, discerned the manufacturers of many items, and thanks to receipts, were also able to determine where the items were purchased.
Most trash items end up on streets only a short distance from where someone bought them. In other words, the majority of litter comes from local sources. This finding could help cities prevent plastic litter that will eventually taint water and air.
“A lot of people say, ‘it’s not my trash,’” said Win Cowger, a UCR environmental scientist and first author on the study. “I want to dispel that notion with the evidence we have, at least here in the Inland Empire.”
Some people have theorized that wind, water or other factors are responsible for moving litter through urban areas. This study, published in the journal Environmental Research, was the first of its kind to examine local litter in such close detail and identify that humans were the primary means by which it moves from sellers to streets.
To reach these conclusions, 18 undergraduate and graduate students trained in data collection surveyed up to 3,280 feet of roadside several times a week in Riverside, Moreno Valley, Loma Linda, San Dimas and Palm Desert.
Nearly 60 percent of the materials they found were plastic. Most were food related, followed by tobacco products. Correspondingly, the top producers of these items, when they were identifiable, were Philip Morris, Mars Incorporated, RJ Reynolds and Jack in the Box.
Because people are responsible for the flow of items from stores onto streets, it can be tempting to blame bad behavior for litter. However, the researchers feel individuals, policy makers, and manufacturers must all work together to solve the problem.
