Hazardous Air Pollutants (Herein expressed as HAPs) are diverse in their variety and difficult to measure and analyze due to their relatively low concentration levels within the environment. For the case of Korea, initiatives to address growing needs over regulating HAPs levels are essentially non-existent. Emissions factor and estimation studies are generally lacking, as regulatory framework along with emission standards have not yet been established. As measuring air pollutant levels require highly concise and systematic calculative approaches, current research outputs and methodologies alone are not sufficient to effectively address issues arising from HAPs emissions. As such, new initiatives and studies to address risks associated with HAPs levels will be of paramount importance going forward.
According to research published by NATA of US. EPA and MATES (California), non-road mobile sources produce less emissions than on-road mobile sources, but produce substantially higher levels of HAPs, making non-road mobile sources an increasingly important subject to research and study. In addition, WHO has classified Diesel PM as grade A carcinogens due to its proven effects on increasing risks for lung cancer to exposed targets. Therefore, it is important to conduct research into not only the subject of Diesel PM and its influence on the human body, but also on sources such as diesel vehicles and non-road mobile sources which predominantly rely on diesel consumption. This study will calculate HAPs emissions levels from non-road mobile sources by utilizing concentration levels of HAPs emissions within air pollutant emissions inventory.
Results show that railroads, marine vessels, and aircraft sectors emit the highest levels of Formaldehyde at 390.33 ton/yr. In addition, these sectors produce 173.55 ton/yr of Acetaldehyde and 54.66 ton/yr of Benzene. Proportion of HAPs emissions levels of Non-road mobile sources are as follows: Formaldehyde - Construction equipment (70.1%), marine vessels (15.5%), agricultural machinery (12.4)%. Acetaldehyde - Construction equipment (72.4%), marine vessels (14.6%), agricultural machinery ( 12.8%). Benzene - marine vessels (67.0%), construction equipment (18.6%), aircraft (11.1%).
Among the top 10 pollutants identified in this study, 9 were identical to those identified by studies conducted in the U.S. These pollutants include Formaldehyde, Acetaldehyde, Benzene, Propionaldehyde, Hexane, Xylene, Toluene, Napthalene, and Acrolein. Both studies reveal that Formaldehyde, Acetaldehyde, and Benzene, in order of emission levels from highest to lowest, are the three most commonly identified pollutants from non-road mobile sources.
By providing measurements for HAPs emissions levels from non-road mobile sources, this study will be able to help prioritize regions which are susceptible to such pollutants and be utilized as valuable reference material for additional research going forward.