Microplastics are increasingly contaminating European rivers, as confirmed by 14 studies published in ‘Environmental Science and Pollution Research.’ Research conducted in 2019 across nine major rivers revealed an average of three microplastic particles per cubic meter of water. Despite lower concentrations compared to the world’s most polluted rivers, significant amounts still enter waterways. Notably, 25% of these microplastics stem from industrial sources. The research involved a collaborative effort from numerous scientists and students, emphasizing the need for awareness and action against this environmental threat.
Microplastics: A Widespread Threat to European Rivers
Microplastics have become an alarming presence in European waterways, as highlighted by 14 studies recently published in the journal ‘Environmental Science and Pollution Research.’ According to Jean-François Ghiglione, a research director at CNRS specializing in marine microbial ecotoxicology, pollution permeates every river examined across Europe. This extensive research initiative took place in 2019 and focused on nine significant rivers throughout the continent.
Methodology and Findings from the Tara Microplastics Expedition
The research team employed a consistent methodology across renowned rivers such as the Elbe, Ebro, Garonne, Loire, Rhône, Rhine, Seine, Thames, and Tiber. They meticulously collected and analyzed samples starting from the river mouths and moving upstream to the first major urban area along each river. This ambitious Tara Microplastics expedition involved 40 chemists, biologists, and physicists from 19 research laboratories, along with numerous PhD candidates and post-doctoral researchers, all supported by the Tara Ocean Foundation.
Microplastics, defined as particles smaller than 5 millimeters, often go unnoticed by the naked eye. As Alexandra Ter Halle, a physical chemist at CNRS in Toulouse, explains, these tiny pollutants include synthetic fibers shed during laundry, microparticles from tire wear, and virgin granules from the plastic manufacturing process. Alarmingly, researchers have found an average of three microplastic particles per cubic meter of water in the rivers studied.
While this figure is significantly lower than the 40 microplastics per cubic meter found in the world’s most polluted rivers, it still raises concerns. For instance, the Rhône River in Valencia experiences a flow rate of 1,000 cubic meters per second, translating to approximately 3,000 plastic particles entering the river every second. The Seine River sees around 900 particles per second, highlighting the pervasive nature of this pollution.
Notably, scientists have discovered that the mass of smaller, invisible microplastics exceeds that of their larger counterparts. Jean-François Ghiglione notes that while larger microplastics float and are easily collected from the surface, the smaller particles disperse throughout the water column, posing a risk to various organisms that may ingest them.
One study revealed the presence of a dangerous bacterium on a microplastic found in the Loire River, which could lead to human infections. Moreover, an unexpected finding showed that approximately 25% of the microplastics identified in these rivers originated not from waste but rather from primary industrial plastics. These granules, often referred to as ‘mermaid tears,’ are sometimes washed ashore following maritime accidents. This insight was made possible through an innovative participatory science project called ‘Plastic Under the Microscope,’ which engages around 15,000 students annually from 350 French middle and high school classes in collecting samples along riverbanks.