Currently, research on plastic degradation in aquatic environments is focused on marine settings. A common criterion is that materials should degrade within two years or faster than comparable standard materials. However, these criteria are defined solely for seawater and do not consider northern conditions, where water bodies freeze during winter.
Finnish research at the University of Jyväskylä has shown that the degradation of plastics is influenced by factors such as the structure of microbial communities, water temperature, nutrient levels, humus content, and salinity.
As part of the PlastLIFE project promoting the circular economy of plastics, the University of Jyväskylä studied the degradability of various biodegradable plastics in lake water and the Baltic Sea using two different methods. Differences were observed in how plastics degraded in lake water versus brackish water, and the chosen method also affected the results.
The research highlights the varying behaviour and fate of plastics in freshwater and brackish environments, as well as the impact of the selected methodology on outcomes. Moreover, current standard methods do not account for Finland’s four distinct seasons. According to the study, degradation during summer temperatures is three times faster than in autumn, winter, or spring.
Threats and opportunities of biodegradable plastics – Action recommendations for decision-makers
We have published seven action recommendations for decision-makers regarding biodegradable plastics. These take into account Finland’s environmental conditions in terms of degradation and provide guidance on updating standards and certification systems. Considering northern conditions in standards also creates opportunities for Finnish research and innovation.
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In the newly published recommendations, we explore the threats and opportunities of biodegradable plastics and share further insights from our research on their biodegradability in soil, water, and recycling facilities.
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Sari Kauppi
Senior researcher, Finnish Environment Institute (Syke)
firstname.lastname@syke.fi
Salla Selonen
Senior reseacher, Finnish Environment Institute (Syke)
firstname.lastname@syke.fi
Anna Virolainen-Hynnä
Leading biogas expert, Finnish Biocycle and Biogas Association
anna.virolainen-hynna@biokierto.fi
