Microplastic Pollution in Urban Agricultural Ecosystems

Assessing and Mitigating Microplastics in Urban Agriculture

How can we build more sustainable cities that equitably promote circular production and consumption?

Urban agriculture has been targeted as a solution to foster clean water, air and soil, as well as reduce inequities in access to nutritious food. Farming in urban and residential areas can help to alleviate food insecurity in food deserts, which are disproportionally located in lower income neighborhoods and communities of color. Urban agriculture can also provide habitat to declining wildlife, such as birds and insect pollinators. Installation of gardens along boulevards, rights of way and in other pockets of urban land can build habitat corridors that facilitate healthy urban ecosystems, along with human well-being.

However, the empty lots or patches of land that are available for urban gardening often have a legacy of pollution. In many cases, toxic inputs continue through adjacent roads, leaded fuel in small plane deposition or pesticide application. While much attention has been paid to heavy metals as pollutants in urban gardens, we are only starting to understand microplastics, a contaminant of emerging concern, in these systems.

This project assessed microplastic pollution in Twin Cities urban gardens and local pollinators, and tested biochar as a strategy to reduce microplastic movement from soils into crops and consumers.

Project Goals

• Sample ten agricultural field sites across the Twin Cities, including five gardens in the urban core and five gardens in suburban and rural areas
• Test the efficacy of biochar as a soil amendment to bind microplastics and reduce their movement in the ecosystem
• Assess the risk of microplastics in these urban green spaces to pollinators