Maria Sighicelli

Microplastic pollution in the surface waters of Italian Subalpine Lakes

Plastic debris incidence in marine environment was already highlighted in the early 1970s. Over the last decade, microplastic pollution in the environment has received increasing attention and is now an emerging research area. Many studies have focused on quantifying microplastic abundance in the marine environment, while there are relatively few data on microplastic occurrence in freshwater environment. Recent studies have reported high concentrations of microplastics in lakes and rivers, although the understanding of several factors influencing source, transport and fate is still limited. This study compares different lakes and the common factors, which could influence the occurrence and distribution of microplastics. The three subalpine lakes monitored include Lake Maggiore, Iseo and Garda. The selected sampling transects reflect the hydrologic conditions, the morphometric characteristics of these lakes, and other factors influencing the release of plastics debris in lakes. Particles of microplastics (<5 mm) were found in all sampled surfaces. The particles collected were classified depending on their number, shape and composition. The shape distribution showed the dominating occurrence of fragments (73.7%). The chemical composition of all examined samples clearly shows dominating presence of polyethylene (45%), polystyrene (18%) and polypropylene (15%). The results provide significant relations among the different contribution of direct and diffuse sources to the quantity of microplastics, highlighting the importance of understanding the spatial distribution dynamics of microplastics within a lake system that acts as a sink and source of plastic particles.

Assessing the poplar photochemical response to high zinc concentrations by image processing and statistical approach

Abstract Exposure of plants to high-heavy metals concentration inhibits multiple metabolic processes in plants and leads to an oxidative stress commonly referred as heavy metal ion toxicity. Chlorophyll a fluorescence has enhanced understanding of heavy metal ion action on the photosynthetic system. A rapid and non-invasive technique involving imaging of chlorophyll fluorescence is a useful tool for early detection of plant responses to heavy metal ion toxicity. In this work chlorophyll fluorescence emission and photochemical parameters in plants of Populus x euramericana clone I-214 were investigated by the portable Imaging PAM fluorometer at different days after soil treatment with zinc. Custom software for analysis of the photochemical parameters images has been developed in order to gain a better assessing of the plant performance in response of metal stress. The imaging analysis allowed visualizing heterogeneity in plant response to high zinc concentrations. The heterogeneity of images suggests spatial differences in photochemical activity and changes in the antenna down-regulation.

Assessment of Microplastics Marine Pollution from an Environmental NGO’s Point of View: The First Study About the Widespread Presence of Plastic Pellets Along the Italian Coast

Raw materials used for the fabrication of plastic products, namely pellets or nurdles are an important source of microplastics dispersed in the marine environment. They can reach the environment for accidental loss during transportation or as result of an improper handling.

Qualitative detection of Mg content in a leaf of Hedera helix by using X-ray radiation from a laser plasma source.

In this article, a method to reveal the presence of Mg content inside the different parts of leaves of Hedera helix is presented. In fact a sample of a Hedera helixs leaf, commonly characterized by a green and a white side, is analyzed under X‐ray radiation. The presence of two zones with different colors in the Hedera helixs leaf has not been explained. In this connection, there are presently three hypotheses to explain the characteristic double‐color appearance of the leaf. The first hypothesis suggests a different cytoplasmic inheritance of chloroplasts at the cell division, the second a different allelic composition, homozygote and heterozygote, between the two zones, and finally the third the action of a virus which changes the color properties in the Hederas leaves. The resulting effect is a different content of “something” between the green and the white side. We utilized X‐ray radiation, obtained from a plasma source with a Mg target, to image Hedera helix leaves and we found that the green side of the leaf is highlighted. We may suppose that the reason why the X‐rays from a Mg plasma source, allow us to pick up the green side is probably due to the greater presence of the amount of Mg (from chlorophyll or other complexes and/or salts) in the two sides, green and white, of the leaf. Microsc. Res. Tech., 2008.