Geophagy and microplastic ingestion

Microplastics (MPs) are ubiquitous and pervasive contaminants whose impacts on human health are unclear but are gaining interest in the scientific literature. Human exposure to MPs may arise through inhalation and ingestion, with research into the latter route focusing on foodstuffs and beverages contaminated from the environment or during processing and preparation. What has not been considered thus far, however, is MP exposure through geophagy, or the cultural, culinary or compulsive ingestion of contaminated soil and dirt. In this study, soils from the island of Hormoz, Iran, and spices prepared from these soils were analysed for MP contamination. Fibres of polyethylene terephthalate, nylon, polystyrene or polypropylene were detected in the soils and a composite spice derived from packaged products, with the MP concentration greatest in the latter sample (0.1 MP g(-1)). Although typical consumption of this material results in MP exposure that is lower than that arising from the dietary consumption of fish and bottled water, for example, geophagy more generally may represent a significant means of exposure for humans and animals that deliberately ingest geosolids.

Automated summary

Microplastics (MPs) are widespread contaminants and their impact on human health is still uncertain but of increasing interest in the scientific community. This study investigated MP contamination in soils from Hormoz Island, Iran and spices made from these soils. Fibres of various types of plastics were detected in the soils and composite spice, with the highest concentration found in the spice (0.1 MP g(-1)). Geophagy, the ingestion of contaminated soil and dirt, could be a significant means of MP exposure for humans and animals.