Information about time spent in microenvironments plays a critical role in exposure assessment of the person concerned, considering that personal exposure relies on the characterization of time-activity patterns of the population at risk as human activities impact the timing, location, and level of personal pollutant exposure. The purpose of this paper was to present the time-activity patterns of Korean adults from a population-based study, and to determine the time spent each day in microenvironments. The population-based study collected time-activity data of about 46,000 adults for two consecutive days on weekdays (n=28,152) and weekends (n=18,800). The mean times spent at one’s own house, workplace or school, other’s house house, restaurant or bar, other places, and transportation related to the whole sample of 28,152 people were 14.90 hrs (62.08%), 4.28 hrs (17.81%), 0.24 hrs (1.01%), 0.51 hrs (2.14%), 2.45 hrs (10.21%), and 1.62 hrs (6.74%) on weekdays, respectively. Looking at the total time spent indoors by adults in different countries, the following four countries were ranked as follows, from lowest to highest: USA > Canada > Korea > Hong Kong. Due to cultural, socioeconomic and climatic differences, it may not be appropriate to directly apply statistical data of other countries to the Korean situation. This paper provides information on how the proportion of persons in different locations changes by time of day, on weekdays and weekends. Here, we can see that over 90% of respondents were in a residence from about 11 PM to 5 AM, and the largest proportion of respondents in workplaces or schools and other places is found between 8 AM and 5 PM.

The information about time spent in microenvironments plays a critical role for an exposure assessment of the person concerned, considering the personal exposure relies on the characterization of activity patterns of the population at risk and human activities impact the timing, location, and level of personal pollutant exposure. The purposes of this paper were to present indoor time activity patterns of Korean from a population-based study and to determine individual factors of time spent in microenvironments. The population based study collected time activity pattern of about 32,000 Korean for two consecutive days. The mean times spent at home, other indoors, outdoors, and transportation in related to the whole sample of 19.025 people are 14.23hrs(59.3%), 6.80hrs(28.3%), 1.26hrs(5.2%), and 1.75hrs(7.3%) in weekday, respectively. Database provides information on how the proportion of persons in different locations changes by time of day in weekday. Here, we see that over 90% of respondents were in a residence from about 11 PM to 5 AM, and the largest proportions of respondents in offices, factories, schools and public buildings occur between 8 AM and 5 PM.

This study investigates weekday/weekend characteristics of PM10 concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO4 2- to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. [NO3 -/SO4 2-] ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and Cl-/Na+ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

This study investigates weekday/weekend characteristics of PM10 and PM2.5 concentration and metallic elements in Busan in the springtime of 2013. PM10 concentration on weekday/weekend were 77.54 and 67.28 ㎍/㎥, respectively. And PM2.5 concentration on weekday/weekend were 57.81 and 43.83 ㎍/㎥, respectively. Also, PM2.5/PM10 concentration ratio on weekdays/weekend was 0.75 and 0.65, respectively. The contribution rates of Na to total metallic elements in PM10 on weekday/weekend were 38.3% and 38.9%, respectively. It would be useful in control effectively with management of urban fine particle to understand characteristics of fine particle concentration on weekday/weekend.

The study investigates weekday/weekend characteristics of PM10 and PM2.5 concentrations and meteorological elements in Busan. The PM10 concentration is highest on Wednesday and Thursday, and lowest on Sunday. On the other hand, the PM2.5 concentration is highest on Wednesday and lowest on Sunday. The location where concentrations of weekdays and weekend differ the most is Hwakjang-dong, the industrial area, and where they differ the least is Gijang-up and Joa-dong, the residential area. Fine particle concentration in the industrial area was consistent at dawn and in the morning, but varied in the afternoon and at night. The visibility of Sunday was 0.49 km higher than that of weekdays, and the solar radiation of Sunday was 0.11 MJ/㎡ higher than that of weekdays. These results indicate that the concentration of fine particles had influence on the change of visibility and solar radiation.