Toxic chemicals from plastic pollution in Lake Geneva


(Photo courtesy of:Pixabay/Technology Networks /Karen Steward)

I moved to Switzerland from Italy about 40 years ago, and I immediately noticed the great difference between the two countries: difference not in beauty, because both are beautiful countries, but in the care, cleanliness and order with which they are mantained. Clearly this difference is all for the benefit of Switzerland, and stands out in an exorbitant manner especially in the Cantons over Gotthard, where there are much more open and extended landscapes. In general, I think I can say that Switzerland is considered, specially abroad, as a wonderful park. Clear waters, manicured grass lawns, beautiful woods, very clean places: never seen any small object abandoned on the lawns or thrown into the water.
So I was literally speechless when I read some studies by Swiss and British Universities researchers, and some articles about macro- and microplastic pollution in Swiss waters.

Lake Geneva is one of the most polluted in Switzerland by plastics!!

In this lake were found hazardous chemicals too, as announced in the above photo, extracted from an article posted in:

According to one of these studies, conducted by Dr. Monterrat Filella of the University of Geneva, and by Dr. Andrew Turner of the University of Plymouth:

Observational Study Unveils the Extensive Presence of Hazardous Elements in Beached Plastics from Lake Geneva“,

published by the magazine “Frontiers in Environmental Sciences “on February 2, 2018,

given that, as the authors write:

The accumulation and impacts of anthropogenic [Note: antropogenic= caused or produced by humans] litter in marine environments has been welldocumented and publicized over the past few decades. In contrast, and despite often easier and more ready access, littering in the freshwater environment has received far less attention, with systematic investigations of rivers and lakes appearing in the literature only recently …

Although they share many similarities with the oceans in terms of usage and anthropogenic pressures, lakes have a smaller fetch, greater enclosure, higher ratio of shoreline to open water, smaller (if any) tidal or haline influence on circulation and transport, and greater sensitivity of water characteristics to local weather conditions. Anthropogenic inputs in lakes are, therefore, likely to be more localized and characterized by a greater land-based and direct human signatures, with a higher proportion of buoyant litter, and in particular low density plastics, ending up beached at the land-water interface (Hoffman and Hittinger, 2017).Regardless of their precise source, plastics deposited on the shores and beds of lakes and suspended in the lentic water column are likely to pose the same problems to wildlife as marine plastics. In this respect, entanglement and ingestion are of greatest concern, with the former having the propensity to suffocate, impair mobility, disrupt feeding and maim, and the latter posing a significant risk of obstruction or damage to the linings of digestive tracts and, through reduced feeding drive, starvation (Gregory, 2009). Ingestion also has the potential to transfer toxins associated with polymers to organisms that consume plastics either directly or through contaminated prey. The majority of studies in this area have targeted persistent organic micropollutants, like polychlorinated biphenyls and polycyclic aromatic hydrocarbons, that are sorbed to the plastic surface …

However, attention has recently been paid to the occurrence and impacts of chemical elements in litter, like metals, metalloids and halogens, that are either adsorbed to the plastic or incorporated into the polymer itself …..

….inorganic additives of the plastic matrix, including flame retardants, catalysts and heavy metal-based pigments, appear to represent a more significant source of contaminants to the foodchain

the two authors found:

potentially toxic elements present in plastics in the lentic environment

collecting samples from 12 beaches around Lake Geneva (or Lac Leman) ..

Over 3,000 samples of plastic litter have been retrieved from 12 pebble beaches around the shores of Lake Geneva. The plastic stock consisted of identifiable objects of various size and color, including bottles, bottle tops, cotton buds, pens, toys, and straws, an heterogeneous assortment of fragments whose origin was either discernible or unknown, and pieces or blocks of expanded polymer (polystyrene or polyurethane foam). Analysis of 670 samples by portable x-ray fluorescence (XRF) spectrometry revealed high concentrations of hazardous elements or compounds among many plastics. These included Cd, Hg, and Pb (with maximum concentrations of 6,760, 810, and 23,500 ppm, respectively) [note: ppm = 1 milligram of element per liter of water (mg/l) or 1 milligram of element per kilogram soil (mg/kg)] as stabilizers in PVC-based materials and/or brightly-colored sulfide or chromate pigments in primary and secondary plastics, and Br (with a maximum concentration of 27,400 ppm) as a proxy for brominated flame retardants (BFRs) in both plastics and foams

Twelve pebble beaches along the Swiss and French shores of Lake Geneva (Figure 1 and Table 1)


were sampled for the present study. Since the lake is heavily used for recreational purposes and most of the beaches are routinely cleaned, particularly in summer, sampling took place on 3 consecutive days in midMarch (and before the Easter holiday break) in 2016. Despite targeting a period outside of the main holiday season, however, organized litter cleaning was witnessed on some of the Swiss beaches, resulting in a lower amount of material retrieved at these locations. Although litter tended to accumulate with wood and other natural debris along strand lines, all material across the entire beach that was visible at the surface to the naked eye and that was wholly or largely constructed of plastic was retrieved by hand.



Number and Type of Plastic Samples

The majority of anthropogenic material observed on each beach was plastic, with manufactured wooden and metallic debris present in lesser quantities and glass entirely absent.


Overall, 3,349 samples were collected, with a total mass of about 4 kg. Items could be classified as primary plastic objects that were usually identifiable (e.g., bottle tops and stoppers, straws, cotton buds, cartridges, clothes pegs, toys, pens, cigarette lighters, cable ties), secondary plastic fragments that were identifiable (e.g., irregular pieces or remains of wire insulation, piping, taping, plant pots, sheetingwrapping, food wrappers, cups, and bottles), secondary plastic fragments that were unidentifiable, or fragments of expanded plastic (hereafter referred to as foam) that were unidentifiable. XRF analysis was restricted to 670 items because of time and resource constraints, with measurements prioritized on the basis of sample variety and reduced by avoiding items that were visually similar in construction, texture and color, both within and between different sites……

Variations in the amount and type of plastic accumulated among the beaches may be attributable to many factors, including proximity to inhabited areas and tributaries, recent history of beach cleaning, circulation, and currents in the lake and beach aspect and slope, but a detailed analysis and source apportionment was not the objective of the present study.


Occurrence and Concentrations of Hazardous Elements

Table 3 shows the frequency of detection and summary statistics for the hazardous elements and ancillary elements in all beached lake plastics analyzed by XRF, …

[note: ppm = 1 milligram of element per liter of water (mg/l) or 1 milligram of element per kilogram soil (mg/kg)]


Bromine was detected in over 20% of the samples analyzed, with concentrations ranging from about 3 to 27,000 ppm. Concentrations of total Br exceeding 1,000 ppm were encountered in 21 items ..

Cadmium was detected in about 16% of lake samples analyzed by XRF, with concentrations ranging from about 20 to 7,000 ppm, and exceedance of the RoHS limit for Cd in plastics of 100 ppm occurred in 57 samples

The present study appears to be the first to provide systematic data on Hg in plastic litter in the aquatic environment. Thus, while traces of the metal were detected in various samples, concentrations above 100 ppm …were restricted to plastic objects and fragments that were always red or reddish-brown and, where analyzed by FTIR, of polyethylene construction. ..

Regarding the lake samples measured here, Cd was present in 10 red plastics where Hg was detected, and in all items where the concentration of Hg exceeded 100 ppm, with Se present in just one case …

Lead was detected in almost one quarter of all samples analyzed, encompassing a wide variety of primary and secondary plastics in terms of size, color and polymer, and in fragments of polyurethane foam. Concentrations ranged from about 5 to 24,000 ppm, with exceedance of the RoHS for the metal of 1,000 ppm occurring in 65 cases ..

There was a striking, significant relationship between Pb and Cr in samples that were non-PVCbased and not green …This suggests that lead chromate and its variants have commonly been employed, in whole or in part (e.g., with Cd-based pigments), to color plastics retrieved from the lake that are yellow, brown, red, or orange.

Comparison with Beached Marine Plastics

The present study is one of only a limited number that have published information on plastics in western Europe’s largest lake (Faure et al., 2012, 2015) or addressed the occurrence of hazardous elements associated with different polymeric matrices in freshwater (Imhof et al., 2016). Several of the findings of our investigation are similar to those arising from studies of beaches in Atlantic Europe; specifically, there is a heterogeneous assortment of primary and secondary plastics and foams, coupled with a plastic pool that is dominated by polyolefins and with a relatively low abundance of higher density materials like PVC which, presumably, has a propensity for sedimentation (Turner, 2016; Fok et al., 2017; Massos and Turner, 2017). Unlike marine plastic surveys, however, there was an absence of primary production pellets and very little filamentous commercial fishing waste, like rope, netting, and cord, retrieved form the shores of the lake. Production pellets are often the dominant form of plastic waste on oceanic beaches on a number basis and, with respect to microplastics (<5 mm in diameter), on a mass basis (Massos and Turner, 2017), with the principal sources related to spillages during transportation (including shipment at sea) and improper handling at processing facilities (Duis and Coors, 2016). Lack of commercial plastic transportation on the lake coupled with efficient waste water treatment in the catchment may account for a limited supply of pellets to the system (Driedger et al., 2015), with a coarse-grained substrate acting to sieve out any residual pellets and other microplastics from the beach surface. …

Compared with equivalent studies conducted on marine beaches (Turner, 2016), hazardous elements appear to occur in higher abundance in plastics retrieved from Lake Geneva.

Potential Impacts of Hazardous Elements on Wildlife

The impacts of hazardous elements and compounds in plastics are largely related to their propensity to migrate from the polymeric matrix and accumulate in biota and there are three potential means by which this may take place. Thus, first, a chemical may slowly leach into the surrounding aqueous medium while plastic is suspended in the water column, providing a general increase in its concentration and availability. Since additives, including pigments, are not designed to leach from plastics, this process is predicted to be slow and of limited importance in circulating water, even after the surface has become weathered and abraded (Nakashima et al., 2016). Secondly, and more significantly, small suspended plastics may be ingested by organisms mistaking items for food, with chemical accumulation occurring via partial but accelerated dissolution under the acidic or enzyme-rich conditions of the gastrointestinal tract (Massos and Turner, 2017).

Thirdly, it is possible that invertebrates may accumulate hazardous chemicals by inhabiting static (e.g., trapped) or moored plastics or by grazing on associated biofilms. For instance, Jang et al. (2016) recently showed that marine mussels inhabiting styrofoam buoys were able to accumulate the BFR, hexabromocyclododecane, that had been impregnated in the polymer during its manufacture.


The present study is among the first to describe both the type and characteristics of beached plastics in Lake Geneva and the occurrence of hazardous elements in fresh water plastic litter ….

The abundance of hazardous elements in beached lake plastics may be attributed to the decadal residence times of low density material in the lake, the age of the plastic stock in the system and the relatively high length of shoreline to surface area of the enclosed water body.

The impacts of plastic-bound toxic elements on lake wildlife are unknown but should form the basis of future empirical investigations. …“

Well, every time I read this study, am flabbergasted.

Some aspects remain very clear after reading it:
1 – Plastic waste contains many toxic chemical metallic- and non-metallic elements
2 – These toxic elements need some time to spread in the environment where they are (water or soil)

3 – If swallowed by the different forms of life of the environment, the plastic particles rapidly release the toxic elements contained, which in turn penetrate into the organism that has ingested them, thus entering in the food chain, at one end of which we are, with the consequences we can imagine.
4 – The forms of life that ingest these plastic materials are not only subject to the poisoning caused by chemicals, but  we can say also to “mechanical” damage caused by the presence of plastic particles, difficult to eliminate, in the digestive system.
5 – The presence of these plastic waste is anthropogenic in nature, that is to say caused by man.

So I would like to conclude with these recommendations:

– First of all, we have to avoid causing further damage to nature and to us by using plastic materials and, specially, leaving them in the environment.
– We must remove those plastic wastes as quickly as possible, to prevent them from altering over the years and to transfer their toxic contents into the environment.

Marcello Micheli/Hydrosphere Association

Many thanks and credit to: Dr. Montserrat Filella Institute F.-A. Forel, University of Geneva, Geneva, Switzerland – and dr. Andrew Turner, School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, United Kingdom for the study carried out.

You can download it in the full version here:



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