Microplastics are typically defined as plastic particles ranging from 1 μm to 5 mm in size, consisting of a diverse mix of synthetic materials, including polypropylene, polyethylene, and polystyrene. These particles can appear in various forms – fragments, fibers, pellets, granules, spheroids, flakes, or beads, – and they are highly resistant to chemicals, temperature, water, and light, as well as bio-neutrality and effective oxygen/moisture barrier properties.

Microplastics are categorized as primary or secondary. Primary microplastics are directly manufactured, often for personal care products and cosmetics, and can also arise from urban dust and the washing of synthetic fabrics. Secondary microplastics result from the degradation of larger plastic items, such as plastic bags, bottles, and fishing nets, through physical, chemical, or biological processes. Both primary and secondary particles can enter marine environments via surface runoff, wastewater discharge, aquaculture and fishing activities, airborne particles, and landfill leachate from household and industrial waste.

In households, microplastics are often washed down drains and enter sewage systems. Traditional wastewater treatment plants, however, struggle to capture these particles due to their minuscule size, resulting in microplastics being discharged into rivers and ultimately the ocean. Because of their stable chemical composition, microplastics can persist in the environment for many years.

In recent years, studies have examined microplastics in marine environments to track their presence, interaction, and buildup in surface waters, sewage sludge, and sandy beaches. Research shows that they pose a threat to sea life, as marine organisms may mistake plastic particles for food, leading to ingestion and potential food-chain transfer.

The Baltic Sea, one of the largest brackish water systems globally, covers about 420,000 km² with an 8,000 km coastline. Surrounded by nine countries and home to about 85 million people, it has some of the highest coastal population densities in Europe. The limited water exchange between the Baltic and the North Sea has led it to be considered one of the most polluted seas. The Baltic Sea is highly industrialized, with heavy ship traffic and pollution from industries along its shores, including plastics production. Marine pollution from fishing and shipping, along with plastic waste, has made it one of the most affected marine ecosystems

There are estimated to be 40 tons of microplastics in the Baltic Sea, largely from personal care products. With the Baltic Sea water exchange being extremely slow, microplastics will stay here possibly forever. The total input of microplastics is still increasing despite the fact that some producers in some countries have been phasing out these products.

What can be done at the municipal level to contribute to reducing the microplastic problem?

1. Implement Filtration at Treatment Plants. Investment  in filtration technologies that effectively capture microplastics in wastewater helps to reduce their entry into water bodies.
2. Promote Real Eco-Friendly Solutions: Encourage citizens to use reusable items instead of single-use plastics and to choose natural fabrics over synthetic ones.
3. Organize Clean-Up Events: Conduct regular clean-up activities along riverbanks, lakeshores, and in parks to decrease the amount of plastic that can break down into microplastics over time.
4. Support Sustainable Businesses: Provide subsidies or tax incentives for companies that minimize plastic use, develop biodegradable alternatives, or utilize recycled materials.
5. Educational Programs for the Community: Offer workshops and campaigns aimed at raising public awareness about the dangers of microplastics and ways to reduce them in daily life.
6. Ban or Restrict Microplastics in Products: For instance, implement restrictions on microplastic components in cosmetics and household products.
7. Collect and Analyze Data: Organize research to monitor microplastic pollution levels and assess their impact on local nature and human health. This will help in planning more effective reduction measures.
8. Support Plastic Recycling Technologies: Subsidize innovations in recycling to more effectively process plastic waste, preventing it from entering the environment.
9. Strict Monitoring of Industrial Emissions: Develop regulations for industrial facilities to reduce plastic and microplastic emissions into the environment, particularly into water bodies.
10. Promote Alternative Materials: Support the production and use of biodegradable and eco-friendly materials instead of traditional plastics in packaging and consumer goods.