You shouldn’t look far to see how we have descended into the Anthropocene, an interval dominated by human impacts on this planet—our moving of mountains and waterways, our corruption of the climate, the traces of nuclear material within the geological record. Add to all that microplastic air pollution, an more and more pervasive menace that’s swirling within the ocean and finding its way to distant corners of the Arctic.
At present in Science Advances, researchers on the Scripps Institution of Oceanography report how the Earth itself is tainted with microplastic particles. By taking a core pattern of sediments directly off the coast of Southern California, the scientists could observe in its layers how plastic concentrations have modified year after year. And exponentially so: Because the 1940s, when plastic manufacturing started to take off, microplastic deposition rates have doubled every 15 years. This correlates with each figure on plastic manufacturing and coastal inhabitants growth in California, and brings us to a troubling conclusion: As seaside cities proceed to increase, so does the quantity of microplastic flowing into the ocean, tainting entire ecosystems.
The researchers bought their sediment samples from one thing referred to as a box core, basically an enormous cookie cutter that slices down a few years’ worths of layers within the seafloor. Again on the lab, they dried every layer and ran the material via filters to isolate the particles, which they counted visually below a microscope and examined chemically to find out the number of plastic.
Curiously, two-thirds of the particles the researchers discovered had been fibers. These are coming mainly from plastic clothing like yoga pants, which slough off threads within the wash. A wastewater treatment plant processes that water earlier than pumping it out to sea, however, isn’t equipped to take away all of the microfibers.