A study jointly conducted by Ocean Wise and Metro Vancouver, and published in the scientific journal Marine Pollution Bulletin, found microplastics shed from laundered clothing a substantial contributor to local pollution.

The study documented microplastic particles in a Metro Vancouver wastewater treatment plant, with 71 per cent of the material observed being fibres such as polyester and modified cellulose (Rayon). For the researchers, these findings raised important questions about the role that household laundry plays in releasing microplastics in the liquid waste that enters Metro Vancouver’s wastewater treatment plants.

“Every time clothing is washed, tiny strands of fabric break off and go down the drain. Research has shown that microplastics in the ocean are being mistaken for food by zooplankton and fish, raising concerns about impacts to their health,” said the study’s principal investigator, Dr. Peter Ross, vice-president of research at Ocean Wise.

There was also good news in the findings. The WWTP, which serves a population of 1.3 million annually, was found to filter up to 99 per cent of microplastics that pass through its system each year.

“We estimate that 1.76 ± 0.31 trillion [microplastics] enter the WWTP annually, with 1.28 ± 0.54 trillion [microplastics] settling into primary sludge, 0.36 ± 0.22 into secondary sludge, and 0.03 ± 0.01 trillion [microplastics] released into the receiving environment,” wrote the researchers.

To achieve this count, the researchers made use of light microscopy to examine influent, primary effluent, secondary effluent, as well as primary and secondary sludge. Fourier Transform Infrared Spectroscopy was used to verify the count, which found that 32.4 per cent of suspected microplastics were plastic polymers.

“Metro Vancouver is the first regional utility in Canada to flag microplastics as an emerging issue in wastewaster,” said Ross. “Having this information is a vital first step in understanding some of the sources of microplastics in the ocean and provides practical guidance as we work together to find and implement solutions.”

Metro Vancouver partnered with Ocean Wise to gain scientific insight and guidance into the emerging topic of microplastic pollution. Additional research is underway to more fully understand the problem and potential mitigation strategies.

“As a regional utility, we need to better understand microplastic pollution and the role our wastewater treatment plants play in preventing environmental impacts,” said Darrell Mussatto, Metro Vancouver’s Chair of the Utilities Committee. “These results clearly demonstrate our wastewater treatment facilities are highly effective in keeping most of these harmful particles out of our oceans, but we can all do better by simply changing our laundry habits.”

Metro Vancouver advised that all Canadian residents can do their part to reduce microplastic pollution by taking the following actions:

  • Doing laundry less frequently when possible
  • Using front-loading laundry machines (which cause clothes to shed four times fewer fibres than top-loading washing machines)
  • Using cold water
  • Using less soap
  • Installing a lint trap or lint filter on your washing machine’s discharge hose

The Ocean Wise Plastics Lab, established in 2014, is an environmental microplastics facility that uses high-end instrumentation to detect and quantify microplastics in environmental samples. The Lab maintains a high-resolution Fourier Transform Infrared spectrometer to identify plastic polymers in fragment and fibres down to 5 microns (0.005 milimetres) in size and employs 12 research staff working on microplastics in wastewater treatment, home laundry, seawater, zooplankton, mussels, and ocean food webs.

The study, Retention of Microplastics in a Major Secondary Wastewater Treatment Plant in Vancouver, Canada, was published last week in Marine Pollution Bulletin, an international scientific journal. It can be found online here.

Cover Image: Microplastic fibres in a marine environment. Credit: M.Danny25


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