Microplastic Contamination in the Human Gastrointestinal Tract and Daily Consumables Associated with an Indonesian Farming Community

Abstract

Plastic is one of the most abundant pollutants in the environment. As a result of natural physical processes, large plastic waste is degraded into microsized particles (<5 mm) called microplastics. Because of their size, abundance, and durability, microplastics are widely distributed in the environment, contaminating food and water intended for human consumption. The extent of microplastic contamination in the human body is still unclear because there are few studies concerning microplastic contamination in human specimens and, in most studies, data were collected from city dwellers. Despite having the fourth largest population and being the fourth largest plastic waste producer in the world and second largest plastic polluter in the ocean, there are currently no data with respect to microplastic exposure for the Indonesian population. Several studies have reported on microplastic contamination in seafood and freshwater organisms from Indonesia, and it is likely that microplastics have contaminated the gastrointestinal tracts of Indonesians. Using Raman spectroscopy, we detected microplastic contamination in 7 out of 11 analyzed stool samples collected from a farming community in the highland village of Pacet, East Java, Indonesia. Polypropylene (PP) was the most abundant and prevalent type of microplastic observed, and it was found in four of the positive samples with an average concentration of 10.19 microgram per gram of feces (μg/g). Microplastics were also detected at high concentrations in tempeh (soybean cake, a staple protein source for Indonesians), table salts, and toothpaste, which were regularly consumed and used by the study participants. PP was particularly high in table salts (2.6 μg/g) and toothpaste (15.42 μg/g), suggesting that these products might contribute to the gastrointestinal contamination in the studied population. This pilot study indicated microplastic contamination in the rural Indonesian population and in their daily consumables, demonstrating the far-reaching extent of microplastic pollution beyond urban areas.