The beautiful clear waters off Rezzonico bear the highest density of micro-plastics on Lake Como

In recent years, and particularly after David Attenborough’s screening of his series Blue Planet 2, there has been growing concern over the amount of plastic in seas and inland waters. In addition to the unsightly and highly visible plastic detritus that circulates the oceans, there is now greater awareness of the presence and dangers of so-called micro-plastics. Micro-plastics are defined as particles of plastic less than 5 mm in length or diameter. These small particles may have broken down from larger items such as plastic bottles but they also derive in original form inserted in cosmetics or from fibres shed from man-made fabrics when being laundered. This latter group are known as primary micro-plastics and they mostly get into rivers, lakes and the seas having first passed through sewage and water purification plants. Some of these particles are microscopic and thus readily digested by fish as well as by those animals including humans exposed to natural untreated water. 

Micro-plastic densities are measured each year now to a depth of 50 metres by Goletta Dei Laghi – part of Legambiente.

No studies yet suggest that ingested micro-plastics are sufficiently small to cross over the stomach lining of either fish or animals to endanger other organs. However research has shown how the micro elements develop a form of natural coating which then provides a host for bacteria including those such as e-coli. In other words, all plastics including micro-plastics are a threat to the environment in general but some may also present a direct threat to health. 

Positive Result: Microbiology

Bellagio’s Beach – one of the cleanest on Lake Como

The ongoing good news is that Goletta dei Laghi confirmed that all sites analysed  during this year’s survey on the Como side of the lake were well within safety limits for bacteria. The same is not the case for micro-plastics. All Northern Italian lakes, unfortunately including Lake Como, have an issue with the amount of plastic pollution. Monitoring for plastics has only started relatively recently thanks to the work of the Goletta dei Laghi, driven by the Italian independent environmental organisation Legambiente. Goletta dei Laghi undertake an annual control of the major Italian lakes checking for both microbiological and micro-plastic levels. Biological readings from the lake are also undertaken monthly from April to October and published on the Internet. As we have reported over the last two years (2018 and 2019), Lake Como’s beaches are mostly well within safety levels particularly those within our own area of interest – the southern part of the lake’s Como leg. Legambiente’s last report in July 2019 confirmed the government’s figures giving a clean bill of microbiological health for all sites checked on Lake Como except for Perlasca, a beach to the north of Varenna. This is particularly reassuring since Legambiente undertake their water sampling at the most critical points where rivers such as the Cosia in Como or the Breggia in Cernobbio enter the lake. Both these rivers have purification plants metres upstream from the lake. 

Negative Result: Microplastics 

A ‘Seabin’ designed to filter out plastic from the lake being installed at Proteus Lab’s HQ at the Darsena di Villa Geno in Como.

The data for micro-plastics leave no space for complacency. Checks on their levels show quantities doubling once water courses have passed through the local purification plants. This means that these plants are not currently equipped with the filters necessary for taking out the particles from domestic or industrial water waste. There are additional problems towards the north of our lake where water flows in from the Rivers Adda and Mera. Figures for micro-plastics are quoted based on a particle count per cubic kilometre. Data for 2018 had Lake Maggiore at the top of the list with 100,000 particles per kilometre followed by Lake Orta with 63,000. Lake Garda followed with 36,000 with Lake Como following with 28,500. The cleanest lake was Iseo with 11,500. However distribution of plastic is very variable and the average figures for Lake Como do not reveal that the limited area between Dervio on the Lecco side and San Siro on the Como side has recorded a maximum count of up to 500,000 particles per cubic kilometre presumably arising from the inadequacies in local filtration and the volumes of water entering from the river systems towards the north of the lake. This does not mean that the area is unsafe for bathing. Yet the high presence of micro-plastics and their capacity to allow for the culture  of harmful bacteria, putting yet another challenge in the way of the regeneration of the lake’s fish stock, does require immediate attention.

Legislation

Plastic drinking straws gathered up by Goletta dei Laghi during this year’s survey of Lake Como

Bio-degradable pasta drinking straws now replace plastic in many of Lake Como’s bars including the lido at Faggeto Lario.

Fortunately some key initiatives to reduce levels of all forms of plastic have been launched on both a national and local level.  Starting nationally, the Italian government banned the use of plastic in ear buds this time last year and followed it further this year with a ban on the use of micro-plastics in any form of cosmetics, e.g. body scrubs and toothpaste. Legislation though can only be part of the answer. The treatment of waste water and sewage needs greater investment to ensure filters prevent the onward spread of particles from human and industrial waste. Equally we all need to reduce the amount of plastic ending up in domestic water waste. Some of this waste, such as the fibres from man-made textiles, are difficult to capture domestically and the ideal of preventing the shedding of micro-plastics from laundry can only be achieved totally if we give up wearing man-made textiles.  

Plastic Free Challenge

The ‘Spazzino’ clears debris from the lake in Como but is not designed to capture micro-plastics.

The Italian Ministry of the Environment in 2018 launched an initiative called the Plastic Free Challenge to raise awareness of the issues and to seek to change both domestic and business behaviours. Some businesses are adapting their habits in order to improve matters. 

The plastic free lido at Faggeto Lario

For example the lido in Faggeto Lario and its bar have declared themselves totally free from single-use plastics. They are the first commercial exercise on the lake to do this. They initially introduced metal reusable drinking straws to accompany their cocktails, as have many other bars in Como, but so many were being lost as customers took them home as a novelty souvenir. They are now using bio-degradable pasta straws. Environmental campaigners Lifegate secured sponsorship from Volvo Italy to install   ‘Seabin’ on the lake at the Darsena di Villa Geno – the headquarters of Proteus Lab. These seabins filter out micro-particles larger than 2 millimetres. Seabins are being installed internationally but the one in Como is the first in Italy to be installed on a freshwater lake. The Spazzino boats who keep Como’s port area free from water-born detritus are fine for ensuring the seaplanes can take off and land safely on the lake without risk but aren’t designed to reduce the quantity of micro-plastics. 

Heavy rainfall brings down a lot of detritus from the mountainsides which must be cleared away to allow for safe landings and take offs for Como’s Aeroclub fleet of seaplanes.

Let’s hope though that the ban on micro-plastics in commercial products combined with the public’s greater awareness of the dangers posed by single-use plastics will quickly lead to reductions in our seas and inland waterways, and in Lake Como. We can be assured that Legambiente, with their annual checks by the Goletta dei Laghi on both biological and plastic waste, will hold national and local administrative entities to account and so provide the necessary third party assurance that our lake is safe for swimmers.  The ongoing improvements year by year in microbiological water quality, undoubtedly due to investments in local drainage and purification systems, cannot allow for any complacency. Our water purification plants now need further enhancement to filter out those micro-plastics originating from domestic or business waste. These particles are too small to offend us visually but they represent another real challenge, on top of climate change, to the ecological health of the lake.

River Adda upstream from Sondrio descends the Valtellina to enter Lake Como in the north and then exits the lake at Lecco to later join the River Po at Lodi.