Forensic determination of adhesive vinyl microplastics in urban soils

Author(s)

Sebastiao, Glaucia I. A. ; Rani-Borges, Barbara ; Dipold, Jessica ; Freitas, Anderson Z. ; Wetter, Niklaus U. ; Ando, Romulo A. ; Waldman, Walter R.

• Document type: Journal article
• Source: Journal of Environmental Management; v. 373, p. 10-pg., 2024-12-06.

Abstract

Plastic production and consumption hubs are mainly concentrated in urban centers, causing the soil in these places to become sinks of plastic fragments. Adhesive vinyl polymers are widely used in various commercial sectors and, to the best of our knowledge, this is the first study to investigate the potential for this type of material to form microplastics in urban soils. This proof-of-concept work started by studying the soil around a sign made of adhesive vinyl that had been exposed to the weather for eight years and showed evident signs of degradation, like cracking and color fading. We separated the microplastics with a two-step density separation protocol and selected only the microplastics targeted by this research, finding up to 5,570 fragments produced from 1 cm2 of adhesive vinyl film. In the soil below the sign, we registered 5.6 x 104 fragments kg-1 of dry soil on its topsoil layer (0-10 cm), 1.2 x 104 fragments kg-1 in the 10-20 cm layer, and 1 x 104 fragments kg-1 in the 20-30 layer. At a distance of 1 and 2 m from the sign, the highest concentration of fragments was also in the topsoil, respectively 9.3 x 103 and 5.3 x 102 fragments kg-1. We also observed that vertical and horizontal transport was not favored, causing the formation of hotspots near the source and that the area of the fragments did not influence vertical transport. Another important finding regarding the characterization technique is that degraded polyvinyl chloride is unlikely to be identified through FTIR without comparison to the source. Here, we presented a low-cost forensic assessment of the association between the presence of MPs and its source that can be used both for the development of public policies and for setting up quality controls for polluting companies. The results here presented reveal the need to rethink the use and types of materials used for visual identities and signage in urban environments. (AU)

• FAPESP's process: 22/11983-4 - Spectroscopy signal enhancement: nanomaterials, theory, and computer simulation
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/15586-0 - Monitoring and characterization of microplastics photoaging combining vibrational spectroscopy approaches and toxic potential evolution
• Grantee: Bárbara Rani Borges
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/12104-4 - Fate and impacts of microplastics and pesticides in aquatic and terrestrial matrices in agricultural contexts
• Grantee: Cassiana Carolina Montagner
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/50332-0 - Scientific, technological and infrastructure qualification in radiopharmaceuticals, radiation and entrepreneurship for health purposes (PDIp)
• Grantee: Marcelo Linardi
• Support Opportunities: Research Grants - State Research Institutes Modernization Program
• FAPESP's process: 18/19240-5 - Multi-user equipment approved in grant 2017-50332-0: STM-AFM Raman SNOM analysis system
• Grantee: Anderson Zanardi de Freitas
• Support Opportunities: Multi-user Equipment Program