Water Resources Research Act Program

Details for Project ID 2019SC235B

Tire wear particles in road runoff as non-point source microplastic pollution in SC waterways

Institute: South Carolina
Year Established: 2019 Start Date: 2019-03-31 End Date: 2020-03-30
Total Federal Funds: $31,040 Total Non-Federal Funds: $62,083

Principal Investigators: Peter Van den Hurk

Project Summary: Recent studies on the distribution and effects of microplastics in the aquatic environment have demonstrated that tire wear particles should be considered a subclass of microplastics, and that these particles are found in the same environments as other microplastics. While for some microplastics obvious point sources can be identified, like plastic fibers coming out of wastewater treatment facilities, tire wear particles enter the waterways through road runoff, which is an example of non-point source pollution. In the U.S., it is estimated that 500 x 106 kg of tire wear particles are released into the environment each year, which makes this a significant source of pollution. Considerable research has been done on the environmental effects of road runoff. However, those studies have mostly focused on dissolved pollutants in the runoff. This approach ignores the contribution of chemical pollutants that are inside the microplastics in general, and tire wear particles in particular. Car tires consist of a variety of chemicals, and some of those are known toxicants, like zinc and polynuclear aromatic hydrocarbons (PAHs). When organisms ingest these particles, which look like regular food items, the chemicals can leach out into the intestinal environment, which is of quite different constitution than the surrounding environment, and can then be absorbed into the organism. While there has been an increased recent public awareness of the environmental effects of microplastics, especially in the coastal and marine environment, very little work has been published on the abundance and possible effects of tire wear particles as subclass of microplastics in the freshwater environment. Through the proposed project, we expect to get a better insight in the potential problems of tire wear particles that enter the aquatic environment as a constituent of road runoff. The results of this project will form the basis for a deeper understanding of the behavior and fate of tire wear particles in the environment, and the potential ecotoxicological impact of these particles on aquatic organisms. The project consists of two major parts: 1) quantify the amount of particles in road runoff that enter waterways during rain storm events. This process is dependent on a variety of road-specific parameters, which will be covered in a comprehensive sampling strategy. 2) measure the toxicological effects of tire wear particles on a model fish species. Because tire rubber contains a variety of chemicals that could be toxic, biochemical responses will be measured in experimentally exposed fish, next to the excretion of these chemicals in bile samples. The intention is to have this project carried out by a group of undergraduate students, under guidance of the PI and a graduate student. This allows for a broader impact and outreach, and makes a larger group of students aware of the nuts and bolts of environmental research. The results will be disseminated through both scientific platforms like publications in scientific journals and presentations at professional meetings, and through presentations in news outlets and meetings for a broader audience.