There are countless types of plastic, and they contain harmful toxins in their own right. In addition, through chemical reactions, they can bind environmental toxins in the seawater, i.e. they function as adhesive surfaces for PCB compounds, for instance.
Plastic litter is mostly found on coasts and in the vicinity of population centres, but the microscopically tiny particles can travel long distances carried by currents and winds. Marine animals are not able to separate them from their food and may end up eating them, as micro-debris is the same size as the natural food of many marine animals. Microlitter has been found in lobsters on the coast of Scotland and in fish from the English Channel.
Why do we need research?
The research into the microscopic plastic litter in oceans is a new and interesting subject whose impact on the state of the environment is not yet certain. A general interest towards the subject is positive for research, even though the public is most interested in the disadvantages for humans, of which there is very little information available at the moment.
Right now, the main purpose of microlitter research is to discover how much microscopic plastic debris is floating in the sea and to which areas it has accumulated. The transfer of debris in the food chain has also been studied worldwide. The most problematic issue in the research at the moment is that the field is new and there are no unified standards for research methods. The standards should be defined at the level of the European Union to make the results comparable with one another.
Researcher at work
Researcher Julia Talvitie works in the project created from the initiative of the City of Helsinki Environment Centre and the Helsinki Region Environmental Services Authority HSY, investigating wastewater as the originating point of microscopic debris in the sea. The project is being funded by the Nessling foundation.
Julia’s usual workday starts either at Viikinmäki wastewater treatment plant or at Otaniemi water laboratory. The main purpose of the current research is to discover how much plastic debris Viikinmäki wastewater treatment plant receives, how the debris is cleaned in the process and what the purified water contains. Different variables, such as the time of day or year, influence what the plant receives, which means that a general estimate, not only based on the load of a specific time, must be drafted.
In practice, the work of a microlitter researcher consists of taking samples at the water treatment plant, filtering the samples and laboratory analyses. Identifying plastic debris in the samples may be quite challenging with only a microscope, which is why verification is made after the researcher’s estimate in a separate materials analysis. It is not possible to estimate the origins of a large portion of the plastic, but they can be classified on a general level; oil- and carbon-based particles are usually black and clothing fibres are recognisable due to their shape.
Julia also joined the Baltic Sea Challenge expedition on m/s Muikku in early autumn 2013, when they analysed the oxygen situation at the bottom of the sea and estimated the amount of microlitter in a dock and on a reference area on Airisto. Even though the working conditions on the ship are very different to those in a normal laboratory, the methods are quite similar to those in treatment plant research – for instance, the filtering device developed in cooperation by Julia and the research experts from the City of Helsinki Environment Centre was also used onboard Muikku.
Solutions to the plastic litter issue
Traffic, industry, fishing and many other human functions produce plastic debris. Even large plastic objects slowly disintegrate into microscopically tiny pieces. At the moment, the production of plastic is inexpensive, and recycling has not been sufficiently invested in. Julia says that there are no methods to remove microlitter from the seawater, which is why the prevention of debris is extremely important. In addition to the intensification of recycling and the development of compensatory materials, water treatment plants alone would be more efficient than before in removing plastic debris if the filtering techniques would be improved. The control and handling of urban runoff should also be taken more carefully into consideration in the process.
Despite the fact that environmental education is invested in and awareness of the importance of recycling keeps improving, the researcher has one wish: the solution to the plastic debris issue requires extensive, legislation-based regulation at the European Union level.