In August, experts from across sectors gathered at the National Academies to discuss the environmental and health impacts of microplastics. The meeting, hosted by the Environmental Health Matters Initiative (EHMI) and the Roundtable on Plastics, provided an overview of the issue and discussed potential ways to alleviate it.

This webinar was a prelude to an upcoming webinar series on microplastics. The series is intended to provide a baseline of information on microplastics, what the concerns are, how complex and multi-sectoral this issue is, and what the starting point is for assessing human health risks.

Microplastics and their Origins

To kick off the webinar, speaker Rob Ellis-Hutchings of Dow explained that microplastics are small pieces of plastic less than five millimeters in length. These plastic pieces are persistent in the environment and contribute to soil, land, and water pollution.

According to Ellis-Hutchings, microplastics are created in two distinct ways: intentional production, called primary microplastics, and unintentional production, called secondary microplastics.

For example, plastic pellets, cosmetic beads, and other particles that are created for a specific function are classified as intentionally created, or primary microplastics. Conversely, unintentional microplastics are created when larger plastics break down through mechanical, chemical or biodegradation processes.

“In reality, all 3 of these stress mechanisms work together to result in, over time, not intentionally produced particles,” Ellis-Hutchings said.

Whether produced intentionally or not, microplastics are prevalent in environmental and human health systems. According to speaker Margaret Spring of the Monterey Bay Aquarium, microplastics derive from many common sources including tires, synthetic clothing, road coatings, and personal care products. 

“The ubiquity of microplastics, not only in the environment but also in bodies of people, are of a grave concern,” Spring said. “We've seen it in all environmental compartments. They're everywhere, and they're in different concentrations.”

Human Exposure to Microplastics

While human exposure to microplastics is difficult to measure, webinar speakers shared that concerns remain about the degree to which microplastics can be found in the tissues and bloodstreams.

“We know that micro- and nano-plastics as well as microfibers, which are shed from synthetic clothes, can make their way to remote corners of the world, as well as to be ingested by and transported within the bodies of living organisms, including us,” speaker Susanne Brander of Oregon State University said.

According to the speakers, because microplastics are so prevalent, it is important to understand their risks to human health.

“We know that there are now 16,000 different chemicals associated with plastics … about 25% are potential chemicals of concern, and a vast majority of those have not been well studied for their toxicity,” speaker Imari Walker-Franklin of RTI International said. “In addition, these small pieces of plastic can also host things like pathogenic bacteria, viruses, and even absorb potentially hazardous heavy metals or other persistent organic pollutants.”

Actions to Control Microplastics

Webinar speakers then discussed current actions and future strategies to remove microplastics from the environment. According to Brander, at the large scale, varied incentives could improve the recapture and collection of plastics.

“Better waste management is, of course, essential,” Brander said. “Educating communities, educating people is essential, but we can't put all of the responsibility on consumers, as we really have been doing. One tool that is being used by five states... is extended producer responsibility. This means that manufacturers of products, like packaging, for example, have to pay for and manage the recycling of those materials that they produce.”

Speakers shared ideas for future research topics across different sectors - including government and policy, academia, and the health, medical, and chemical industries - to solve the microplastic issue. They noted that there is collaborative work occurring today in some of those sectors. According to Spring, there are consortia looking at plastics, legislation in the European Union, and state-level action in the U.S.

“If you want something fast, you go at it alone. But if you want to go far, then you go together,” moderator Babli Kapur of Dow said. “And what we need over here is collaboration across all of the different sectors. We need to leverage the information that we already have in hand, whether it is in the U.S., whether it is internationally generated information, and then we need to see how we can move forward with solutions that are true solutions and do have a positive impact on our environment and on our health.”

Related Resources

• Watch the webinar recording

• Upcoming event in the Microplastics Webinar Series