Estimation of emission of tire wear particles (TWPs) in Korea.

Tire wear particles (TWPs) were one of the source categories of microplastics, and some countries consider it the largest. In the case of Korea, the number of vehicles per a kilometer of road is the highest among 30 OECD countries. Therefore, the concentration of TWPs is considered high. This study aims to estimate TWPs emission factor by using warranty period of tire, driving distance per vehicle per day, weight of tire, and ratio of weight loss of tire, and then, suggests TWPs emission amount by using annual driving distance and emission factor of TWPs of each type of vehicle. As a result, the emission factor of TWPs in Korea appeared as in the following: 45-57 mg/vehicle·km (average 51.1 mg/vehicle·km) for passenger cars, 224 mg/vehicle·km for lightweight trucks, 799 mg/vehicle·km for buses, and 949 mg/vehicle·km for heavyweight trucks. The total amount of TWPs to be generated in a year was calculated as 51,795-54,581 tonnes/year (average 53,188 tonnes/year). The amount of TWPs appeared in the order of heavyweight trucks, buses, passenger cars, and lightweight trucks; the contribution of tires of each type of vehicles, to the emitted amount of TWPs, appeared with insignificant differences.