Snowstorms Are Dropping Microplastics on Remote Parts of the Sierra Nevadas

Researchers have found that snowstorms carry microplastics into remote parts of California’s Sierra Nevada, adding a source of pollution to a mountain snowpack that supplies much of the state’s fresh water. The findings also raise questions about whether airborne plastic could affect weather and climate by influencing cloud formation and absorbing heat.

The study linked individual storms to snowfall containing as many as 3,200 plastic particles per square metre per day. The mass was still very small, at less than a tenth of an ounce per acre per day; the most common plastics were polyethylene, polypropylene and polyester. The researchers did not measure how much reaches drinking water, although about a third of California’s fresh water comes from Sierra Nevada snowpack.