Focus is put on stormwater, which today is an under-investigated pathway of microplastics to the aquatic environment. We sample and analyse microplastics in stormwater from various types of urban catchments such as a trafficked road and a city center. Furthermore, we study how plastic macro litter is degraded to micro- and nano- plastic particles, and the occurance of microplastics in common stormwater treatment facilities.
The data received from these investigations are input to a conceptual model describing how microplastics are transported, retained and released from the urban environment. This model also take other flows and pathways into account, such as the wastewater system, which previously has been studied to a far more extent than stormwater. Moreover, the model give guidance regarding which actors need to be involved in order to diminish the release of microplastics and suitable measures for various pathways is indicated.