The Study of Characteristics for Polycyclic Aromatic Hydrocarbons(PAHs) in Air around Ascon Manufacturing Facilities

This study investigated the concentration levels of PAHs emitted from the emission sources and the distribution characteristics between each measurement point and the site boundary and point of impact, with three Ascon manufacturing facilities in Busan as target facilities. Analysis of 16 PAH congeners designated by the US EPA revealed that the total PAH concentrations across the three Ascon manufacturing facilities ranged from 119.7 to 12,450.2μg/Sm<sup>3</sup>, with the observed variation attributed to differences in the type of fuel combusted in the aggregate drying units and the efficiency of air pollution control devices at each facility. For benzo(a)pyrene, where the air emissions acceptance criteria are applied from January 2020, the concentration level was 0.2 to 0.9μg/Sm<sup>3</sup>, which is lower than the emission acceptance standard of 50μg/Sm<sup>3</sup>. In addition, the concentration ratio of PAHs in the gas phase and particle phase was examined to be 1.5 to 2.5 times higher in the gas phase. According to the survey of PAHs in the atmosphere around the emission facilities, the concentration of PAHs in the atmosphere was not significantly different when the Ascon manufacturing facilities was in operation and in non-operation, but more detailed research is expected in the future because the climate conditions, wind direction and wind speed were not considered during air sampling. It was found that the concentration of PAHs on the gas rather than on particles at the site boundary point was higher, and the difference between the site boundary of the emission source and the point of influence was not significant. In addition, a survey of the distribution of PAHs by substance showed that unlike the emission sources, the characteristics of PAHs at the surrounding and affected points were mainly high in the case of PAHs in the gas phase, with many congeners present in the case of particle phase PAHs. The CALPUFF model was used to identify the impact of three Ascon manufacturing facilities on the surrounding areas on the surrounding areas. The modeling scenario was carried out by inputting the emission of point pollutants by major emission sources calculated above for February, when the highest concentration of exhaust was shown. In all facilities, the correlation coefficient with the actual measurement was found to be 0.9 (p<0.001) relatively high. Therefore, using the modeling results, it is considered reasonable to analyze the effect of PAH in the emission sources on the surrounding areas. After each PAH emission from the Ascon manufacturing facilities being considered in this study was calculated and the CALPUFF modelling by individual material was performed and the equivalent concentration of benzo(a)pyrene by grid was analyzed, and it was found that some areas affected the surrounding area according to the wind direction conditions. These results indicate that some areas around Ascon manufacturing facilities may be affected by PAH emissions under certain wind conditions, with BaPeq concentrations exceeding the UK guideline of 0.25 ng/m<sup>3</sup>.