We don't yet know what microplastics' bounds are if they exist. We seem to discover tiny rubbish everywhere, from the ocean's depths to the highest point on the planet.
We're beginning to understand why. Aside from the alarming discovery of microplastics in our bodies, we now know that these tiny bits may fly through the air, float through the atmosphere, at least until they are stopped by anything.
Scientists used an intriguing way for tracking this insidious air pollution phenomena in a recent study, due to something very natural and also rather common - spiderwebs.
"Spiders are found all over the world, including in cities," explains Barbara Scholz-Böttcher, an organic geochemist at Germany's Carl von Ossietzky University.
"Their sticky webs are an ideal trap for anything that floats through the air."
When you walk through a sticky spiderweb, it may seem like a nightmare, but it turns out that it's a fantastic, organic commodity for measuring particle pollution in the urban environment.
Rebecca Süßmuth, a student researcher from Oldenburg, Germany, gathered spiderwebs tied to street-side bus stops as part of an experiment (with the webs situated about 2 meters or 6.5 ft off the ground).
When the researchers examined the web samples in the lab, they looked for many distinct types of plastic polymer formations; sure enough, the tests confirmed microplastics had attached to the webs.
"All the spiderwebs were contaminated with microplastics," says co-author Isabel Goßmann, who worked on the study as part of her doctoral dissertation.
Microplastic contamination captured in spider webs, according to the research, can account for up to 10% of the weight of the entire web and is made up of a variety of microplastics.
About 90% of the debris was PET (polyethylene terephthalate), with C-PET being the most common polymer, possibly produced from textile fibers, according to the researchers.
Finely ground tire wear particles (TWP), which break off the outside section of tires during braking and acceleration and were predicted to be detected in large quantities given the web collections' roadside location, were another source of microplastics.
TWP rubbers are not technically plastics, but because of their synthetic origin, they are increasingly being included in definitions of microplastic contamination, according to the researchers.
Even if spiderweb sampling isn't as novel as you may assume, the findings serve as yet another sobering reminder of the pervasiveness of microplastic contamination. At the very least, we've uncovered a simple and affordable technique to help monitor the situation.
