Fibrous foes: First report on insidious microplastic contamination in dietary fiber supplements
Logeshwaran Panneerselvan, Haryni Jayaradhika Raghuraman Rengarajan, Raji Kandaiah, Geetika Bhagwat-Russell, Thava Palanisami
Abstract
Regular consumption of health supplements to balance dietary intake has gained popularity worldwide. One such supplement that has gained popularity among consumers is dietary fibers. Microplastic (MPs) contamination in various food products is being reported worldwide. However, there is a paucity of understanding of the occurrence of MPs in dietary supplements. This study addresses this gap by investigating the degree of MPs contamination in dietary fiber supplements. Nine commonly consumed (powder and gummy-based) over-the-counter dietary fiber supplements in Australia were tested in this study. Microscopic examination revealed the presence of MPs fibers and fragments in all the tested products. Further categorization showed that MPs particles were of various colors, including black, blue, red, green, and white. The order of polymer abundance was Polyamide > Polydiallyl Phthalate > polyethylene and polypropylene-diene > Polyurethane = Polyethylene terephthalate > Polyethylene = Ethylene acrylic acid copolymer. Among the supplements, powder-based samples had higher MPs (at the adult dosage suggested by the manufacturer) than gummy-based product. The average predicted ingestion of microplastics from these supplements (all nine samples) was 5.89 ± 2.89 particles day -1 . The dietary exposure for children and adults ranged from 0.1 - 0.48 and 0.18 - 4.08 particles day -1 , respectively. Based on the microplastic contamination factor (MCF), among the nine samples tested, 69.81% exhibited a moderate level, while 20.76% showed a significant level of microplastic contamination. The polymer risk index (pRi) indicates products with very high and high-risk categories. The possible sources of MPs contamination in the products were studied. To our knowledge, this is the first study to record and quantify the presence of MPs in dietary fiber supplements, which is a direct source of MPs exposure to humans via., ingestion. • Microplastics were found in all dietary fiber supplements tested. • Fiber-shaped microplastics and polyamide were the most abundant. • Average intake of microplastics from supplements was found to be 5.89 ± 2.89 particles day -1 • Risk assessments indicated moderate to very high contamination. • We emphasize the necessity of comprehensive quality checks at every production stage.