Global warming and the resulting increase in flooding is expected to send more microplastic pollution into the sea, according to research at the University of Brighton.
Rivers deliver more microplastics into the oceans than any other source and Karolina Skalska, PhD researcher in the University’s Centre for Aquatic Environments, is investigating which flow rates will produce the most pollution.
She said: “It is very important that we understand this process as it is predicted that, due to climate change, we can expect floods of greater frequency and magnitude. This could result in a large increase to the amount of microplastics that enter the seas and pose a risk to the already vulnerable ecosystems.”
Karolina’s research was presented to MPs at the STEM (Science, Technology, Engineering and Mathematics) for Britain finals at Westminster, a contest which aims to “raise the profile of Britain’s early-stage researchers”.
Karolina said microplastics are likely being introduced into the Thames as a result of poor sewage treatment, but there are many other sources of plastic debris in that area: “I have also found various sources of microplastics to the Thames. Fibres, which originate from abrasion of synthetic clothes, tend to dominate at sites located downstream of wastewater treatment plants.
“Fragments, on the other hand, are especially abundant at highly littered sites, as they are usually generated during the environmental breakdown of larger plastics. Beads, which are often used in certain industrial processes (e.g. blasting), are also present near industrial estates.”
The second-year student in the School of Environment and Technology is researching the influence of future changes to flooding patterns on microplastics. This involves field work in the Thames catchment area where she monitors microplastic concentrations all over the river at urban to rural sites.
“This will help me to account for the changes in river flows, which typically increase in the winter as a result of increased rainfall.”
Karolina said once the microplastics flow mechanism is understood “we may be able to potentially capture microplastics before they end up in the marine environment”.
So far, she said, the majority of studies have focused on microplastics in the marine environment. “However, it is rivers that deliver most plastic debris into the seas and oceans. While some microplastics float in fresh waters, large amounts of microplastics have been found in river sediments.
“According to new evidence, plastic debris can be flushed out of the riverbeds once a flood occurs, but we don’t yet know what river flow rates can initiate this process.”
Karolina took part in the finals of the Engineering session of STEM for Britain which “provided me with a unique opportunity to communicate my research to both an expert and a lay audience”.
“I was also very happy to see a lot of exciting research targeting climate change and sustainability. I would encourage every early career academic to apply to next year’s STEM for Britain. It was an extremely positive experience, and I had the chance to meet many special people in a unique place.
“Young researchers have the potential to shape the future of our generation, and it was very encouraging to hear that message from both Parliamentarians and experts in the engineering field.”