Exposure Assessments for Children in Homes and in Daycare Centers to NO 2 , PMs and Black Carbon

Indoor air quality was investigated in homes and daycares located in areas with heavy traffic in Seoul, South Korea from November 2013 to January 2014. Indoor and outdoor air quality measurements were collected for 48 hours in four children’s homes and daycare centers. The I/O ratio (Indoor to outdoor ratio) for each major air pollutant (NO 2 , black carbon, PM 10 , and PM 2.5 ) was calculated, and NO 2 and PM 10 concentration profiles were analyzed based on indoor activity diaries recorded during the 48 hours. Most I/O ratios for NO 2 , black carbon, PM 10 , and PM 2.5 at daycare centers were less than one. At homes, I/O ratios for black carbon, PM 10 , and PM 2.5 were less than one; however, most I/O ratios for NO 2 were greater than one due to the usage of gas stoves. The children’s exposure to indoor air pollutants was calculated using a time-weighted average exposure method, and the daily intake level for each pollutant was determined.