Occurrence and characteristics of microplastics in South African beverages

Abstract

This study presents the first comprehensive assessment of microplastics (MPs) in alcoholic (AB) and non-alcohol (NAB) beverages in South Africa. Beverages in various packaging materials, specifically glass, aluminium, and polyethylene terephthalate (PET) were tested for MP content. The samples were filtered and digested, then stained with Rose Bengal dye to facilitate particle identification, followed by physical and chemical characterisation using stereomicroscopy and micro-Raman spectroscopy, respectively. Fibers were the prevalent shape observed in AB packaged in glass, as well as in NAB (PET), and NAB (Aluminium). The Aluminium samples also exhibited a high abundance of fragments. Multivariate principal component analysis and Pearson correlation coefficient matrix revealed positive correlations between fibers of size ranges 0.02–0.1 mm and 0.1–0.5 mm in NAB samples. While in AB samples, the ranges were observed to be 1–2 mm and 2–3 mm. Six polymers were identified, namely: polypropylene (PP), polyethylene (PE), polyurethane (PU), polyamide (PA), PET, and polybutylene terephthalate (PBT). This study offers a holistic appraisal of MPs in commercially sold beverages in South Africa. It establishes a framework for assessing the socioeconomic impacts of MPs, including their commercial, environmental, social, and sustainability implications.