Micro-plastic pollution is now prevalent throughout much of the the world’s oceans, as a result of discarded partially- broken-down garbage. These microscopic bits of plastic are present in large enough quantities to cause significant problems for many ocean animals, as well as potentially having more significant effects on the ecosystem, or even human health. The full extent of the damage that this pollution causes is as of now unknown though, as there hasn’t been much research done on the subject. And now, new research from EPFL has found that it isn’t just the oceans that are filled with this micro-plastic pollution, lakes and other waterways are accumulating it as well.
The research found that one of Western Europe’s largest lakes — Lake Geneva — is host to large enough quantities of the stuff to raise significant concerns.
“We were surprised to find such high concentrations of microplastics, especially in an environmentally aware country like Switzerland,” says first author Florian Faure from EPFL. The new study was focused on Lake Geneva, “where both beaches and lake water were shown to contain significant amounts of microplastic contamination — pieces of plastic waste up to 5 mm in diameter.”
The research is some of the first to focus micro-plastic pollution within a continental freshwater lake. And according to the researchers, “given the massive efforts put into protecting the lakes shores over the past decades, both on its French and the Swiss shores, the situation is likely to be representative of fresh water bodies around the world.”
EPFL gets into the details:
Microplastics in continental waters may be the main source of microplastic pollution in oceans, where huge hotspots containing high concentrations of these pollutants have formed. Scientists estimate that only around 20% of oceanic microplastics are dumped straight into the sea. The remaining 80% are estimated to originate from terrestrial sources, such as waste dumps, street litter, and sewage.
Microplastic pollution is also a strain to lake and river ecosystems, threatening the animals that inhabit these aquatic ecosystems both physically and chemically. When inadvertently swallowed by aquatic birds and fish, the tiny bits of plastic can wind up stuck in the animals’ intestines, where they obstruct their digestive tracts, or cause them to suffocate by blocking their airways. Ingested plastics may also leach toxic additives and other pollutants stuck to their surface into the animals that swallow them, such as bisphenol A (BPA) and phthalates, two carcinogenic agents used in transparent plastics, or other hydrophobic water pollutants, such as PCBs.
The researchers utilized an array of different approaches in order to quantify the plastic and microplastic pollution in and around the lake — including combing the beaches along Lake Geneva, dissecting dead animals and fishes, and analyzing bird droppings from around the lake.
To measure the concentration of microplastics in the water, Faure worked in collaboration with Oceaneye, a Geneva-based non-profit organization. Using an approach developed to study plastic pollution in the Mediterranean Sea, they pulled a manta trawl — a floating thin-meshed net — behind a boat in Lake Geneva to pick up any solid matter in the top layer of the water. The samples were then sorted out, dried and the solid compounds were analyzed for their composition.
“We found plastic in every sample we took from the beaches,” says Faure. “Polystyrene beads were the most common culprits, but hard plastics, plastic membranes, and bits of fishing line were also widespread. In this preliminary study, the amount of debris caught in Lake Geneva using the manta trawl was comparable to measurements made in the Mediterranean Sea.”
The researchers are now planning to expand their focus to include lakes and rivers throughout the whole country, backed by a mandate from the Swiss Federal Office for the Environment. This work will investigate the micro-plastic pollution present in lakes, rivers, and biota across the whole country, and also, perhaps more-importantly, the associated micro-pollutants, such as PCBs. PCBs were found stuck onto the micro-plastics taken from Lake Geneva in very significant concentrations.
The new research was recently published in the journal Archives des Sciences.