The potential risk of microplastics accumulation in farmland soils and vegetables from the development of rural tourism

Development of rural tourism, such as in the Erhai Lake region of China's Yunnan Province, can lead to significant increases in farmers' incomes. However, the large amounts of plastic waste generated by tourism activities may increase microplastics (MPs) concentrations in surrounding farmland soils and pose a risk to human health. Here, we investigated the abundance and characteristics of MPs in farmland soils and vegetables in the Erhai Lake region. The results show that there are significantly higher MP concentrations in developed areas compared to areas that have not been developed for tourism. Specifically, the MP abundances in developed vs. traditional village soils were 6486 ± 3665 vs 1525 ± 656 MP/kg. We further found that developed farmlands had approximately twice the MP abundance of traditional farmlands. There was a significant increase in fragmented (+225.6 %) and granular (+40.0 MP/kg) MPs in the developed farmland soils, and these MPs were mainly in the forms of polyethylene and polypropylene. Vegetables grown on soils of developed areas also had higher MP pollutants. Leafy vegetables contained 7.7 ± 3.8 MPs/5g when grown on soils in developed areas, compared to 2.8 ± 0.9 MPs/5g in non-developed areas. Adult residents in developed areas were found to have accumulated approximately 1.41 × 10 more MPs annually via vegetable consumption compared to adults who live in non-developed areas. In conclusion, the development of tourism in the Erhai Lake region has significantly increased the microplastics content in surrounding farmland soils and vegetables, posing a potential threat to agricultural production and to ecosystems, and to human health via bioaccumulation.