The Korea Institute of Machinery and Materials (KIMM), under the Ministry of Science and ICT, has succeeded in the world's first integrated measurement of vehicle-generated fine dust, including not only engine combustion but also tire and brake wear, and is expected to be used as supporting data for future non-exhaust fine dust reduction policies.

The Korea Institute of Machinery and Materials announced that it has succeeded in comprehensively measuring fine dust generated during the operation of internal combustion and electric vehicles due to engine combustion, tire and brake wear, road wear, and road re-suspended dust.

Automobile fine dust can be classified into exhaust fine dust generated by engine combustion, etc., and non-exhaust fine dust generated when dust that has settled on the roadside or tires, brakes, roads, etc., is scattered again by the movement of vehicles.

A research team led by Dr. Lee Seok-hwan of the Mobility Power Research Laboratory at the Korea Institute of Machinery and Materials (KIMM) Carbon Neutrality Research Center conducted an integrated experimental measurement of fine dust emissions by vehicle type for domestic compact SUVs, utilizing a mobile road dust measurement vehicle along with self-developed tire wear simulators and brake wear simulators.

The measurement results for gasoline, diesel, and electric vehicles (90% regenerative braking) show PM10 (fine dust) standards of 42.3 mg/km, 43.2 mg/km, 47.7 mg/km, and P, respectively, in that order.Fine dust levels of 14.5 mg/km, 14.1 mg/km, and 13.9 mg/km were generated based on M2.5 (ultrafine dust) standards.

To date, only the amount of fine dust generated from brake wear has been studied. In the case of other non-exhaust fine dust sources, such as tire or road wear, research on measuring generation amounts or identifying phenomena has not been properly conducted. Until now, fine dust emissions have been calculated using estimates based on emission factors for each source listed in the national emission inventory.

The Korea Institute of Machinery and Materials' attempt to calculate fine dust emissions through integrated experimental measurements by vehicle type (internal combustion and electric vehicles) and emission source (exhaust and non-exhaust) is a world first. It is expected to be used as supporting data for identifying the causes of non-exhaust particulate matter generated from internal combustion engines and electric vehicles, and for supporting related environmental policies.

In the case of the latest internal combustion engine vehicles, the emission of exhaust particulate matter is low due to the development of engine combustion and aftertreatment devices, and accordingly, it has been found that more than 90% of the particulate matter generated by vehicles originates from non-exhaust particulate matter.

Of the 42.3 mg/km of fine dust generated from gasoline vehicles, road resuspension dust, road wear, and tire/brake wear were measured at 19.3 mg/km, 10.7 mg/km, and 11.3 mg/km, respectively, while the amount of fine dust generated from exhaust was only 1.0 mg/km.

In the case of electric vehicles (90% regenerative braking), it was measured that out of a total of 47.7 mg/km of fine dust, road re-suspended dust, road wear, and tire/brake wear accounted for 23.5 mg/km, 13.1 mg/km, and 10.5 mg/km, respectively.

Lee Seok-hwan, a principal researcher at the Korea Institute of Machinery and Materials (KIMM), stated, “Although electric vehicles emit no harmful exhaust gases or greenhouse gases, integrated experimental measurements have confirmed that a significant level of non-exhaust fine dust is generated.” He added, “To improve urban air quality, multifaceted measures to reduce non-exhaust fine dust must be prepared alongside policies to promote the adoption of electric vehicles.”

This study was conducted with the support of the Ministry of Science and ICT's 'Characterization of Fine Dust by Automobile Emission Source' project, and the results of this study were published in the prestigious SCI journal 'Science of the Total Environment'.