Importance of non-residential environmental concentration in exposure assessment in Korea

KIYOUNG LEE (1), Wonho Yang (2)

(1) Seoul National University, Seoul, Korea, (2) Catholic University of Daegu, Daegu, Korea

     Abstract Number: 89
     Last modified: October 28, 2009

Abstract
Information on time spent in microenvironments plays a critical role for personal exposure to environmental pollutants. Unlike several large-scale studies in Western countries, no comprehensive research on time-activity patterns for exposure assessment has been conducted in Korea. We investigated determinants of residential indoor and transportation times of individuals over 10 years old in the Korean population. The population-based study collected time-activity patterns of 31,634 Koreans for two consecutive days. The residential indoor and transportation times were collected for a weekday and a weekend day. The impact of sociodemographic factors on time-activity was assessed using multiple linear regression models. The residential indoor times were 14.23 hours for the weekday and 16.13 hours for the weekend and shorter than those in Western countries. The transportation times were 1.75 hours for the weekday and 1.68 hours for the weekend day. Korean population spent less time at home after the working hours. The time spent in residential indoor at 6 PM and 10 PM were about 37% and 75%, respectively. These residential indoor time were different from the results of about 67% (6 PM) and 90% (10 PM) in USA. The most significant factors in residential indoor time were employment status, age, monthly income, and gender for the weekday and employment status and gender for the weekend day. The factors in transportation were gender, employment status, and monthly income for the weekday and gender, employment status, age, and marriage status for the weekend day. Determinants of the time-activity pattern need to be taken into account in exposure assessment, epidemiological analyses, and exposure simulations, as well as in the development of preventive strategies. Since Korean population activity patterns are substantially different from those in Western countries, this information could be critical for exposure assessment in Korea.