microplastics

By: Matthew Coomer, Intern with the NOAA Marine Debris Program

You may not think about wastewater treatment plants (WWTPs) very often, but you use them every day. In fact, they are essential to protecting our health and the environment; WWTPs change our sewage into clean water that can safely re-enter rivers and the ocean. These facilities are complex, but to simplify, they filter solid material out of wastewater, allow microorganisms to feed on the organic matter that’s left behind, and then kill any dangerous bacteria. Whenever you use water at home or in your community, you use your local WWTP. Unfortunately, while these treatment plants are very good at their job, they may also be point sources of a persistent type of marine debris— microplastics.

Microplastics are a type of plastic marine debris that are less than five millimeters in size. Research on this type of debris has become more widespread, but since there is no single agreed-upon method for separating, counting, and weighing microplastics in water samples, it is difficult to compare results across studies. Common approaches may be used, but most laboratories develop their own procedures based on factors such as budget, equipment availability, labor, and the specific research questions being asked.

Since so many different protocols are being used, the NOAA Marine Debris Program partnered with researchers at the University of Washington Tacoma to compare different methodologies.  

On Monday, December 28^th, President Obama signed the Microbead-Free Waters Act of 2015 into law. This new law bans plastic microbeads in cosmetics and personal care products, requiring companies to stop manufacturing products that contain them. Microbeads are tiny plastic beads that have commonly been added as abrasives to health and beauty products such as exfoliating face washes and toothpastes, and are designed to wash down the drain. Congress’ swift passage of this legislation is reflective of a growing movement to ban microbeads at the state level– in 2015 alone, 47 bills to ban microbeads were introduced in 25 state legislatures and nine were signed into law.