어린이활동공간의 실내 먼지 종류별 납 농도와 노출수준

Lead Concentrations and Exposure Levels by Dust Type in Children’s Indoor Activity Zone

Background: Indoor dust, a major source of lead exposure, contains contaminants from soil, household items, and building materials. Children are especially vulnerable to this due to hand-to-mouth behavior and higher absorption rates. Objectives: This study aims to improve children’s environmental safety by identifying major sources of lead in indoor dust, characterizing exposure patterns within children’s activity zones, and estimating lead exposure levels by dust type. Methods: This study examined the presence of lead in architectural components (floors, walls, doors, windows, built-in cabinets) and furnishings in 55 daycare centers. On-site measurements were conducted using a portable XRF analyzer, followed by the collection and ICP-OES analysis of indoor dust samples for lead content. Results: Lead concentrations in indoor dust followed the order of exterior window frame>inner window frame>window net>air purifier pre-filter > floor. The exceedance rates of the EPA standard for window sills (0.1 μg/cm ) were 36.4% for exterior window frame dust (20/55). All floor dust samples were below the EPA 2 standard of 0.01 μg/cm . Inner window frame dust showed a moderate correlation with air purifier pre-filter 2 dust (r=0.63, p<0.05), while exterior frame dust had a weaker but significant link with window net dust (r=0.34, p<0.05). PVC windows showed higher lead levels, but their correlation with window dust was low and not significant (r=0.18, p=0.29). Conclusions: At the 95th percentile, the average daily dose (ADD) of lead from exterior window frame dust was 4.26E-03 mg/kgㆍday, up to 640 times higher than that from floor dust 6.66E-06 mg/kgㆍday, highlighting the need for further investigation and management. Attempts to identify major indoor sources, such as paints and finishes, were inconclusive due to data limitations. These findings highlight the need for ongoing monitoring and indicate that outdoor sources could play a significant role in indoor lead contamination.