(CBS SF) — Alarmingly high levels of pollution from tiny pieces of plastic are contaminating the San Francisco Bay, according to a new study.

The San Jose Mercury News reports nearly 3.9 million pieces of plastic enter the bay every day from eight sewage treatment plants.

READ MORE: UPDATE: Cal Fire Crews Reach 80% Containment on Fremont Fire Near Napa-Sonoma County Line

Those plastic pieces range from microbeads used in facial scrubs to synthetic fabric on clothes that break down when they’re washed.

By dragging nets around the bay, researchers at the San Francisco Estuary Institute uncovered 1 million pieces of plastic per square kilometer in the South Bay — nine times higher the concentration that levels in Lake Erie, the most polluted of the Great Lakes. Near Oakland and San Francisco, the team found 310,000 pieces per square kilometer — triple the levels in Lake Erie.

READ MORE: Millbrae Resident Sleeping In Bed Robbed In Home Invasion

The study found the microplastic pollutants to be so wide-spread that it could possibly be affecting people who eat fish caught in the bay.

“The micro-particles are of concern to us,” executive director of Bay Area Clean Water Agencies David Williams told the San Jose Mercury News. “We’ve known for some time that there are things that our plants just don’t remove.”

Earlier this month, state lawmakers passed a bill that would ban the use of microbeads in beauty products.

MORE NEWS: New Wildfire Breaks Out Near Shasta Lake, Quickly Grows to 50 Acres

It’s unclear whether Gov. Brown would sign the ban, which would be the strictist of its kind in the country.