Pollution, 17 different polymers found in Lake Orta, concentration of microplastics

Microplastics in the waters of Lake Orta (Cusio), the westernmost of the large Italian pre-alpine lakes. This was highlighted by Legambiente, which today, Monday 7 July, presented a study entitled 'Monitoring microplastics in Lake Orta' carried out by Arpa Piemonte in collaboration with ENEA and Legambiente Piemonte and Valle d'Aosta. Sampling on Lake Orta was carried out in 2022 (May and October) and in 2023 (June and October) to determine the type and abundance of microplastics along three transects.

In the samplings carried out along the Piedmont shore, the presence of 17 different polymers and an average concentration of microplastics between 0.04 and 1.58 particles/m3 were found, values consistent with the average of microplastics found in the Italian lakes monitored in recent years by Legambiente. Among the most commonly found microplastics: polyethylene (from a minimum of 46% in the June 2023 campaign to a maximum of 91% in the October 2022 campaign); polypropylene (minimum percentage of 7% in October 2022 and maximum of 47% in June 2023); polyamide detected, albeit in a minor presence, in all the samplings (from <1% to 6.7%). The data were presented at a meeting entitled 'State of the art and proposals in the study of microplastic dispersion: which technologies? Which perspectives?" organised in Pella, in the province of Novara, by Goletta dei Laghi for the campaign's 20th anniversary.

The environmental association points out that according to recent studies, microplastics may be able to slow down the growth of phytoplankton; make the soil less fertile; and that they may accelerate the melting of snow and ice, diminishing the albedo effect and accelerating the effect of climate change. However, the negative effects due to the potential transfer of pollutants contained in microplastics from the stomachs of fish to other tissues, and from the fragments themselves being inhaled or ingested by humans, remain to be clarified.