Gaseous emissions from vehicles contribute substantially to air pollution and climate change. Vehicular emissions also contain secondary pollutants produced via chemical reactions that occur between the emitted gases and atmospheric air. This study aims at understanding patterns concerning emission of regulated, greenhouse, and precursor gases, which demonstrate potential for secondary aerosol (SA) formation, from vehicles incorporating different engine technologies—multi-point injection (MPI) and gasoline direct injection (GDI)—and using different fuels—gasoline, liquefied petroleum gas (LPG), and diesel. Drive cycles from the National Institute of Environmental Research (NIER) were used in this study. Results obtained from drive cycle tests demonstrate a decline in aggregate gas emissions corresponding to an increase in average vehicle speed. CO₂ accounts for more than 99% of aggregate gaseous emissions. In terms of concentration, CO and NH₃ form predominantly non-CO₂ emissions from gasoline and LPG vehicles, whereas nitrogen oxides (NOx) and non-methane hydrocarbons (NMHC) dominate diesel-vehicle emissions. A higher percentage of SO₂ is emitted from diesel vehicles compared to their gasoline- and LPG-powered counterparts. EURO-5- and EURO-6-compliant vehicles equipped with diesel particulate filters (DPFs) tend to emit higher amounts of NO₂ compared to EURO-3-compliant vehicles, which are not equipped with DPFs. Vehicles incorporating GDI tend to emit less CO₂ compared to those incorporating MPI, albeit at the expense of increased CO emissions. The authors believe that results reported in this paper concerning regulated and unregulated pollutant-emission monitoring can contribute towards an accurate evaluation of both primary and secondary air-pollution scenarios in Korea.

The need to regulate the non-exhaust particulate matter (PM) emissions from vehicles has been discussed worldwide due to the bad environmental impact and the toxicity to the human body. In-depth studies have been precisely conducted on the analysis of the non-exhaust particulate matters, in particular, the amount of tire, brake and road wear particles and their proportion in the atmosphere. In this study, the influence of tire and road wear particles (TRWP) on PM in the atmosphere was investigated with tire and PM samples. The PM samples suspended in the atmosphere were collected with a high-volume sampler equipped with a quartz filter. Additionally, polycyclic aromatic hydrocarbons (PAHs) and metal components in tire rubber were analyzed as markers by pyrolysis–gas chromatography/mass spectrometry (pyrolysis–GC/MS), GC/MS, and inductively coupled plasma/mass spectrometry (ICP/MS). More vinylcyclohexene was detected than dipentene in the markers measured in the samples of tires equipped with vehicles driving on the road, while more dipentene was measured in total suspended particles (TSP) samples. Among the PAHs in tire samples, pyrene exhibited the highest concentration. Benzo(b)fluoranthene showed the highest concentration in the TSP samples. Among the metals, the highest concentration was zinc in all tire samples and calcium in TSP samples.

The need to regulate the non-exhaust particulate emissions from vehicles has been discussed worldwide due to the toxicity to the human body as well as the atmosphere. In-depth studies have been conducted on precise analysis of the non-exhaust particulates, in particular, accurate measurement of tire-brake-road wear particles, and their proportion in the atmosphere. In this study, the influence of tire and road wear particles (TRWP) on particulate matter (PM) in the atmosphere was investigated through tire and PM samples. PM samples were collected from the atmosphere using a high-volume sampler equipped with a quartz filter. Additionally, polycyclic aromatic hydrocarbons (PAHs) and heavy metals in tire rubber were analyzed as markers by pyrolysis-gas chromatography/mass spectrometry (GC/MS), GC/MS, and inductively coupled plasma/mass spectrometry (ICP/MS). More vinylcyclohexene was detected than dipentene in the markers measured in the samples of tires equipped with vehicles driving on the road with the high-volume sampler installed, while more dipentene was detected in total suspended particles (TSP) samples. Among the PAHs measured in tire samples, pyrene exhibited the highest concentration. In TSP samples, benzo(b)fluoranthene showed the highest concentration. Among the heavy metals, zinc exhibited the highest concentration in all tire samples and calcium in TSP samples.

Extensive research about non-exhaust fine particles from tires and brakes in vehicles has been reported, focusing on the significant effects on air pollution and human harm. Significant investigations are still needed in determining the cause of influence on the environment and human health. The regulations on emissions have been discussed in earnest, starting with the introduction of brake wear particle emission standards in Euro 7. Various indoor and outdoor experiments have been conducted, such as analysis of the amount of wear on tires and brakes, and analysis of the physical and chemical properties of fine particles, and the effect of non-exhaust fine wear particles on the atmosphere and human health, as fundamental data for the introduction of emission standards and the development of low-wear tires and brakes to meet regulations. Recently, international standardized indoor experimental methods for brakes have been announced, and indoor and outdoor experimental methods for tires have been continuously studied to develop international standardized methods. In particular, tire and road wear particles, including brake wear particles, are usually mixed with each other in the non-exhaust particles from a vehicle driving on real roads, and in-depth research is being performed on their accurate classification and characteristic analysis. In this study, the characteristics of the volatile organic compounds and marker substances for tire and tire and road wear particles were analyzed. A system was installed on the vehicle to collect non-exhaust wear fine particles from the vehicle running on two different roads, urban and suburban, of the Seoul area, and the proving ground road. The specific findings are as follows: (1) From the chemical analysis of the volatile organic compounds, high n-hexane and n-dodecane were measured in the tire–road-wear particles. (2) The volatile organic compound species in the PM2.5 (aerodynamic diameter ≤ 2.5 µm) increased as the vehicle velocity increased. (3) For the PM10 (aerodynamic diameter ≤ 10 µm), high volatile organic compound species were recorded at 40 km/h of the vehicle velocity. (4) This study also revealed that higher vinylcyclohexene and dipentene were measured in the particle size below 10 μm than those in PM2.5.

Non-exhaust fine particles such as tires and brakes emitted from vehicles have a significant impact on air pollution and human harm, and regulations on emissions are being discussed in earnest, starting with the introduction of brake wear particles emission standards in Euro 7. Various indoor and outdoor experiments were conducted, such as analysis of the amount of wear on tires and brakes, and analysis of the physical and chemical properties of fine particles, as fundamental data for the introduction of emission standards and the development of low wear tires and brakes to meet regulations. Recently, international standardized indoor experimental methods for brakes have been announced, and indoor and outdoor experimental methods for tires have been continuously studied to develop international standardized methods. In particular, tire-break-road wear particles are usually mixed with each other in the non-exhaust particles from a vehicle driving on real roads, and in-depth research is being performed on the accurate classification and characteristic analysis. In this study, the characteristics of the volatile organic components (VOCs) and marker substances for tire and tire-road wear fine particles were analyzed. A system capable of measuring non-exhaust wear fine particles was installed on the vehicle, and samples were collected from the vehicle running on the two different driving conditions, various constant speeds in the proving ground road and real driving roads. The VOCs contained in tires and tire-road-wear particles (TRWPs) under the specific temperature conditions with a thermogravimetric analyzergas chromatography/mass analysis (TGA-GC/MS). In addition, the correlations between VOCs and tire rubber components were analyzed through marker analysis using pyrolysis-gas chromatography/mass analysis (GC/MS). In VOCs, n-Hexane, n-Dodecane, and 1-Butene were measured relatively much in both constant-speed and real-drive tests. In addition, marker substances of synthetic rubber and natural rubber were not detected in the collected background fine particles.