Microplastics from recyclable plastics on the rise

Recyclable plastic has been recorded on popular beaches and urban watercourses in Adelaide, South Australia – highlighting the need for more efforts to remove and reuse all plastics from waste streams, particularly in urban areas.

Flinders University researchers extracted 417 microplastic particles from 285 samples of sediment from the Onkaparinga River and Patawalonga Creek as well as sand from several local beaches in the SA capital city, finding most of the microplastics were from recyclable products.

"Clearly plastic waste will be more abundant in urbanised areas but it's concerning that we are finding more evidence of recyclable plastic pollution in our rivers, creeks and beaches," says first author in a new article Anna Hayes.

Distribution of microplastics in marine environments tends to be underestimated when mixed with sediment, while low density microplastics are also held in suspension in water – particularly in slow velocity rivers and streams, adds co-author College of Science and Engineering Associate Professor Sophie Leterme, from the Flinders Institute for Nanoscale Science and Technology.

"In particular the water and sediment from the slow flowing Patawalonga Creek contained a higher level of microplastic compared to what we found at nearby Glenelg Beach, the Onkaparinga River and Southport Beach," says Associate Professor Leterme.

"We need to improve our waste management practices and implement better recycling strategies to not only clean up urban environments but to also help improve coastal, marine and estuarine water quality."    

"This study also gives insight into how river flow is a major environmental influence on the accumulation of microplastics in river and beach sediment," adds Professor of Forensic Science Paul Kirkbride, another co-author.