Microplastics are spread over arable fields – can microplastic threaten the production of safe food and can plastic end up on our dinner plate?
Sewage sludge from municipal water treatment plants are used as fertilizer in farmland today, because the sludge contains valuable nutrients, and recovery of plant nutrients are accounted as part of «the green shift ».
However, the problem is that today’s water treatment plant also receives large amounts of microplastic (small plastic particles < 5 mm) together with the wastewater from households, industry and surface water from towns. It is assumed that most, approximately 90 % of the microplastic received end up in the wastewater sludge that are used as fertilizer in the arable fields.
The last couple of years the it has been directed particular attention to the increasing amount of plastic in the sea, however it is assumed that more plastic is received in farmland by sludge than in the sea. Nevertheless, there are extensive knowledge gaps on what happens when the plastic comes in the soil and what consequences it has in consideration to food safety, sustainability and environment.
As part of being a responsible part of society and develop safe products, IVAR sees that more knowledge and research on the area is needed, and together with IRIS researchers they will investigate to what degree municipal water treatment plants, are point sources to microplastics to the food chain on land and to sea.
There will in addition be research to understand the potential accumulation of plastic particles in the soil and the organisms that live there, in plants for human consumption and biological effects of the particles. A question of special interest will be if microplastic particles in the soil can be taken up by plants and vegetables, and thus, find its way through the food chain, and end up on our plate.
IRIS and IVAR is currently cooperating on developing methodology that can analyze microplastic in wastewater and in sewage sludge, and will later customize this methodology to use in analyses of soil and plant material. This will give great benefit in consideration to food safety and environment.
Findings of the project will give a necessary basis to considerate if there is a need of increased focus to develop waste management facilities, that are better prepared to handle this new environmental problem, in a way that gives more sustainable use of resources and increased safety for consumers. The project will chart (and possible avoid) problems that are related to food safety and other environmental aspects and will therefore make safer use of sewage sludge as a resource. This will give a good knowledgebase and will be important for further expansion and diversification of fertilize production, and the growing demand the society has for recycling, and so called circular economy can be safeguarded.
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