Scientists have detected harmful chemicals including cadmium, mercury and lead in plastic samples taken from Lake Geneva, which sits on the border between Switzerland and France. The study is first of its kind conducted in Lake Geneva and warrants further research into the environmental impacts these chemicals may have on the lake’s wildlife, according to the authors.
Although litter in marine environments has received significant attention in recent years, there has been little research into trash in freshwater bodies. The study’s findings show that like marine ecosystems, freshwater environments are also affected by plastic pollution.
The study was conducted by researchers at the University of Geneva in Switzerland and the University of Plymouth in the United Kingdom. Their work, published recently in Frontiers in Environmental Science, is the “first-ever chemical analysis of plastic collected from beaches around Lake Geneva,” according to a University of Plymouth press release published on Tuesday.
“Freshwater systems have been largely overlooked with regards to the impact of plastic,” said study co-author Dr Andrew Turner of the University of Plymouth. “Most studies thus far have focussed on the oceans. This is one of only a handful of studies of plastics in lakes.”
Researchers collected more than 3,000 samples of plastic debris from 12 beaches around Lake Geneva, which is one of the largest bodies of freshwater in western Europe. Using portable x-ray fluorescence (XRF) spectrometry, researchers conducted an analysis of 670 of the samples to determine their composition.
“A lot of the plastic was similar to that found on marine beaches, such as bottle tops, straws and polystyrene,” said Dr Montserrat Filella of the University of Geneva. However, there was a lack materials associated with commercial fishing, such as fibres from rope, netting and cord, which are often found on marine beaches.
The results of the analysis showed high concentrations of hazardous chemicals in a number of the samples, sometimes exceeding limits set by European Union laws. The team detected bromine in more than one-fifth of the samples they analysed, with concentrations ranging from around 3 to 27,000 ppm.
“We detected the frequent presence of hazardous elements, such as bromine, cadmium, mercury and lead, in very high concentrations in some cases,” said Dr Turner.
Some of the chemicals found are no longer permitted in plastic products, suggesting the plastic samples have been in the lake for some time.
“The abundance of these toxic elements, which are now restricted or banned, reflects just how long the plastic has been in the lake,” said Dr Turner. “For example, mercury is a metal that to our knowledge has not been used in plastics for decades.”
Plastics in and around lakes are “likely to pose the same problems to wildlife as marine plastics,” with “entanglement and ingestion” being the biggest concerns, according to the study.
However, the scientists said further research is necessary to determine the impacts the presence of these chemicals has had on nearby wildlife.
“The impacts of plastic-bound toxic elements on lake wildlife are currently unknown,” said Dr Filella, adding that this “should form the basis of future research.”