Recognizing microplastic deposits on sandy beaches by altimetric positioning, Μ-Raman spectroscopy, and multivariate statistical models

Abstract

This study examines microplastic (MP) pollution along São Paulo State's coast, southeastern Brazil, using geodetic surveys, beach morphometric analyses, sediment collection, µ-RAMAN spectrometry, and multivariate statistical models. The coastline was divided into six compartments (C1 to C6) for sampling. Higher MP concentrations were found in C3 and C2, influenced by industrial and port activities. MP types, including pellets, fragments, and fibers, showed distinct distribution patterns based on their sources and properties. Fragments and foams were most common, constituting 42% and 35% of the 1,026 MPs found. Statistical tests linked MP types to beach morphometric characteristics, with higher elevations correlating with higher MP concentrations, especially pellets and foams. Beaches with intermediate profiles and those facing south accumulated more MPs. The study highlights the complexity of MP dynamics in coastal environments and the need for developing specific monitoring and environmental remediation strategies, supporting Sustainable Development Goal 14 (Life Below Water).