The Swedish authorities aim to reduce the spread of microplastics in the environment. As part of this effort, last fall the Swedish Environmental Protection Agency commissioned IVL to identify the sources and pathways of microplastics in the marine environment. The study will be completed by the summer of 2016.
According to Kerstin Magnusson, ecotoxicologist at IVL Swedish Environmental Research Institute, microplastic particles are particularly worrisome — compared to other microdebris toxic, emissions from microplastics increase over time as plastic degrades physically very slowly in water.
Microplastic particles in the marine environment may originate from a variety of different sources; they may be fragments of larger pieces of debris but may also be man-made micro particles, such as the microplastic pellets used as raw material in the plastics industry, and as ingredients in personal care products. Sewage treatment facilities are common supply routes of microplastics. In a previous study, Kerstin Magnusson has shown that considerable volumes of microplastics are to be found in outgoing water flows from these plants. The Henriksdal waste water treatment facility in Stockholm discharges several million plastic particles in the size range 0.02 to 5 millimeters per hour.
– Because plastic particles break down extremely slowly, concentrations in the environment will inevitably increase as long as accretions from wastewater treatment plants and similar routes are not mitigated. It is vital that sewage treatment plants develop methods to prevent the outflow of particles into the environment, but it is even more important to reduce microdebris discharges in wastewater from households and industries, says Kerstin Magnusson.
The assignment she has been tasked with by the Swedish Environmental Protection Agency has enabled her to map out land-based sources of microplastics emissions that eventually end up in the marine environment, and to prioritize the sources in Sweden that should be addressed first.
Last week the Swedish Chemicals Agency published a report proposing a nationwide ban on the sale of cosmetic rinse-off products containing plastic microbeads. Microbeads are plastic particles designed to have a cleansing or scrubbing effect, such as exfoliating body-wash shower gels.
– The microplastics that come from personal care products and cosmetics constitute a small percentage of the total amount of microplastics in the marine environment, but this is an unnecessary source that can be dealt with relatively easily, says Kerstin Magnusson.
Microplastics are small plastic particles less than 5 millimeters in diameter. They are taken up by aquatic filter feeders such as mussels and plankton. It is suspected that microplastics may be more harmful to wildlife than larger debris, due to the fact that they act as carriers of organic pollutants and heavy metals.