Time-series and spatial analysis of collected odor complaints in Seoul megacity during 2014~2021 were conducted for the characterization of odor complaints emitted from the living environment. The ratio of odor complaints in the environmental complaints was 16.7%, and odor complaints increased 3.3 times from 9,053 cases in 2014 to a maximum of 29,425 cases in 2019. In the time-based evaluation (monthly, daily (day of the week), and hourly variations), the highest number of complaints occurred in June, Monday, and 9:00 AM, respectively. While the lowest number of complaints occurred in December, Sunday, and 3:00 AM, respectively. Among 25 provinces in Seoul megacity, the odor complaints that occurred from 2014 to 2021 were concentrated in Eunpyeonggu. The odor complaints of Seodaemun-gu and Nowon-gu occurred at the highest levels in January-February and June, respectively. Based on the characteristics of odor complaint occurrence according to the above time-series and spatial analyses, more effective odor management and control can be implemented by focusing on those hotspot areas and specific time periods.

Volatile organic compounds(VOCs) detected frequently in the indoor air of child-care centers causes neurological disorders, lung, eyes, and bronchial irritation, and acute and chronic toxicity. In this study, the distributions of carcinogenic VOCs detected in child-care centers were characterized and a health risk assessment of the VOCs was performed, which can provide the necessary information for drawing up safety plans with respect to the concerned materials. The sampling of sites in day-care centers was undertaken two times: in the morning (10:00~12:00), and afternoon(16:00~20:00)-at 23 daycare centers located in Seoul, Korea from April, 2012 to July, 2012. The overall average concentrations of individual VOCs were benzene(1.61 μg/m3) > carbon tetrachloride (0.78 μg/m3) > chloroform(0.67 μg/m3) in order. Indoor/outdoor(I/O) ratios of benzene, carbon tetrachloride, chloroform were 1.33, 1.09, 1.72, respectively. Benzene and carbon tetrachloride are thought to be more strongly associated with outdoor sources as compared to chloroform. Spearman correlation of benzene, carbon tetrachloride between indoor and outdoor concentration showed statistically significant levels(p < 0.05). The linear correlations for benzene, styrene, and carbon tetrachloride were tested. A significant correlation was observed only for carbon tetrachloride, accounting for 83 % of the variance. The risk assessment of the carcinogenic VOCs for teachers, infants, and children showed that none of the targeted VOCs posed a serious risk.