Every year, an estimated 8 to 12 million tons of plastic enter the Ocean. All the world‘s oceanic and coastal ecosystems are currently threatened by plastic pollution, detrimental to marine species (strangulation, ingestion…), seabeds (deterioration of the sea floor) and to human through adverse socio-economic impacts.
Over the 15 past years, leakages of millions of plastic biocarriers - supports for bacterial growth used in certain types of Wastewater Treatment Plants (WWTPs) have been reported in riverine and marine environments. In most cases, these biocarriers are not recovered in the aquatic environment, thus contributing to the issue of global plastic pollution.
Different studies were undertaken to identify the sources of such leakages and around 40 study cases were analysed to improve understanding of the causes of this type of pollution from WWTPs. In Nordic countries, pollution cases have been reported in Sweden, Iceland, Denmark and Norway. The physical properties of biocarriers, make them highly mobile pollutants with the capacity for rapid dispersion in the aquatic environment.
Of the 15 contracting parties of the OSPAR Convention, at least 11 are directly affected by biocarrier pollution.
Biocarrier leakages fall into two principal categories: either massive one-off (acute) leakages or more difficult-to-track chronic diffuse leaks. Municipal and industrial WWTPs of any size and location can be affected.
To address this type of plastic pollution and reduce its environmental impact, the Swedish Environmental Protection Agency has become involved in the issue.