## 4 Conclusions  
This work aimed to quantify the presence of plastic beach litter in the Como Bay (Italy) to track the main sources and processes of plastic contamination in freshwater bodies, and to assess the likely nature of secondary MPs. Moreover, since data regarding MPs in Como Lake sediments are still lacking, this could be a key factor for supporting further research on the distribution of MPs in littoral sediments, giving insights into the possible composition of (secondary) MPs. Indeed, according to our data, the most widespread polymers are PE (>40%) and PP (>32%), while other commonly used polymers represent approximately 17% of beach litter. Considering the types of sampled objects, in all the studied sites, packaging represents the most abundant category (>34%).  
Since no previous data regarding the distribution of plastic litter are available for this study area, it is not possible to recognize a temporal trend in plastic distribution along the coast. However, our study allowed us to identify the most plausible contamination routes for plastic litter accumulation. A general accordance between the most accessible beaches and pollution loads highlights that in-site littering plays an important role. Moreover, the distribution of plastics in the study area suggests that part of the plastic waste can accumulate via longitudinal transport on the water surface, in accordance with the main regional wind currents. This information can be used to better address waste management strategies and the control of litter production in the neighboring coastal area, as well as giving important insights into the possible composition of secondary microplastics on the lake shoreline. In addition, local governments could promote dissemination campaigns through educational activities, such as local beach cleaning, which could increase awareness in citizens. Such activities could also offer opportunities for collecting data on plastic abundance, distribution, and composition, to be used for scientific purposes.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app1211538/s1](https://www.mdpi.com/article/10.3390/app1211538/s1)]([https://www.mdpi.com/article/10.3390/app1211538/s1](https://www.mdpi.com/article/10.3390/app1211538/s1)), Table S1: Detailed list of sampled objects. The type of object, size (in cm) and the polymeric composition are reported for each item; Table S2: Correlation values (R) for FTIR obtained by comparison with Openspecy database; Table S3: Correlation table of different site properties and plastic litter densities. Values > 0.5 are highlighted in bold. The obtained \(p\)-values are also included (in italics); Figure S1: Number of objects for different dimensional classes in all the sampled sites; Figure S2: Objects and polymers recovered from different beaches. On the left side: pie graphs reporting the polymeric composition of recovered objects; on the right side: sample composition in terms of \"object categories\".  
Conceptualization: A.B.; methodology: A.B. and G.B. ([PERSON]); data curation: [PERSON]. ([PERSON]) and A.B.; writing--original draft preparation: [PERSON]; writing--review and editing: [PERSON]. ([PERSON]), [PERSON] ([PERSON]), and [PERSON]; supervision: [PERSON] and [PERSON]. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.