Researchers have learned a great deal about marine and freshwater plastic pollution. And the results worry scientists and public health experts. Microplastics are fragments that form as plastics erode. Study after study show that they are ubiquitous. They’re found in seafood, in bottled water, and even in the placentas of unborn babies.
But tracing those tiny bits of plastic to their source is exceptionally difficult. A microscope can’t tell you whether a plastic fragment comes from a fishing line, a plastic bottle, synthetic apparel, or some other source. For that, scientists use a device called a Raman spectrometer.
Emily Miller, a senior research fellow at Monterey Bay Aquarium who led the study, told KALW how the spectrometer works. "You shoot a laser at a sample, and scientists can get a molecular fingerprint from the way that the light in the laser interacts with the molecules in your sample," she said.
Miller and her colleagues built a reference library of 24 such molecular fingerprints from microplastic samples pulled from Monterey Bay. Researchers can use this library to trace the origin of microplastics they find. And unlike similar libraries made by for-profit laboratories, access to this new resource is free. Miller says it will help democratize the study of microplastic pollution.
