Scientists say they have found high levels of small plastic particles in Arctic snow. Their findings provide more evidence that plastic is entering Earth’s atmosphere and traveling great distances around the planet. A new report describing the discovery was published in Science Advances. A German-Swiss research team collected snow samples from the Arctic and other areas. They included northern Germany, the Bavarian and Swiss Alps, and the North Sea island of Heligoland. When the researchers examined the samples in a laboratory, they were surprised to find very high levels of microplastics. Microplastics are very small pieces of plastic. These plastic particles are generally smaller than 5 millimeters in length. Other studies have found microplastics in the environment.