This study was conducted to propose a way to increase the accuracy and precision of β-ray measurement equipment. Statistical processing results of equivalent evaluation data from 2016 to 2021 confirmed that the concentration of micro dust measured by β-ray measurement equipment was higher than that of micro dust sampler. According to quarterly data, it was confirmed that the data from the third quarter (July to September) showed a different trend from other periods, which is assumed to be due to weather conditions. This study indicates that automatic micro-dust measurement equipment evaluation at air pollution measuring stations during the third quarter should be excluded. The evaluation cycle should be changed from once every two years to quarterly. In addition, when the criterion for determining equivalence evaluation falls within the range of the slope and intercept values of the existing trend line, it is necessary to evaluate the R2 value together and reduce the slope from 0.9-1.1 to 0.9-1.0.

Nowadays micro-dust is a serious problem in Korea. In particular micro-dust contains heavy metals such as Pb (lead) and Cd (cadmium) which negatively effect on human health. In this study, we intended to isolate lactic acid bacteria which can scavenge the heavy metals. Firstly we isolated two lactic acid bacteria which were resistant to Ag, Cu, and Zn (30-100 mM AgNO3, CuSO4, ZnSO4 in MRS broth). The two lactic acid bacteria CJNU 1877 and JG 15 were identified Lactobacillus paracasei and Enterococcus faecium, respectively. Subsequently the strains were inoculated in MRS broth and agar plate where 100 ppm of Pb(NO3)2 and CdSO4 were added, respectively. They did grow in the conditions and we found aggregations from 24 h cultures, indicating the strains can absorb the heavy metals, which was further proved by scanning electron microscopy (SEM) and Inductively Coupled Plasma-Optical Emission Spectrometer. Therefore the isolated lactic acid bacteria can be used as a probiotics harboring heavy metal scavenging activity.