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Park J.,Seoul National University | Lee L.,Seoul National University | Byun H.,Seoul National University | Ham S.,Seoul National University | And 7 more authors.
Journal of Cleaner Production | Year: 2014

Volatile organic compounds (VOCs) are potentially harmful air pollutants that are commonly encountered in urban environments. Various chemicals known to produce VOCs are used in laboratory fume hoods; however little research has been done to show the effect of such chemicals and associated VOCs on the local air quality. This study aims to assess the concentration of various VOCs emitted from the exhaust stacks of rooftop fume hoods mounted on laboratory buildings, as well as to determine factors that contribute to different concentrations of commonly encountered VOCs. A total of six university campus buildings, comprising four laboratory buildings and two non-laboratory buildings as controls, were selected as case studies. VOCs were sampled using activated charcoal tubes in front of fume hood exhausts located on the rooftops of buildings and were analyzed GC/FID. Factors such as meteorological conditions and the amount of chemicals utilized in the building of interest were investigated. A total of 11 individual compounds were quantified in the samples collected. The concentrations of 11 VOCs at laboratory buildings were significantly higher (GM; 184.74 μg/m3, GSD; 3.38) than those of non-laboratory buildings (GM; 12.1 μg/m3, GSD; 1.64, p < 0.001). The concentrations of 10 individual compounds emitted from laboratory buildings were significantly higher than those emitted from non-laboratory buildings (p < 0.001) with the exception of m- and p-xylene (p = 0.155). We found that the amount of chemical use was the predominant factor determining the composition and concentrations of VOCs found (p < 0.001). From this study, we suggest that installation of an air purification system in fume hood ventilation systems is necessary to prevent atmospheric pollution and adverse health effects in university populations, as well as supporting efforts towards creating 'green campus' environments. © 2013 Elsevier Ltd. All rights reserved.

Kwon J.-T.,Seoul National University | Kwon J.-T.,National Institute of Environmental Research | Minai-Tehrani A.,Seoul National University | Hwang S.-K.,Seoul National University | And 14 more authors.
Toxicological Research | Year: 2012

The purpose of this study was to determine the acute pulmonary toxicity of metallic silver nanoparticles (MSNPs, 20.30 nm in diameter). Acute pulmonary toxicity and body distribution of inhaled MSNPs in mice were evaluated using a nose-only exposure chamber (NOEC) system. Bronchoalveolar lavage (BAL) fluid analysis, Western blotting, histopathological changes, and silver burdens in various organs were determined in mice. Mice were exposed to MSNPs for 6 hrs. The mean concentration, total surface area, volume and mass concentrations in the NOEC were maintained at 1.93 × 107 particles/cm3, 1.09 × 1010 nm2/cm3, 2.72 × 1011 nm3/cm3, and 2854.62 μg/m3, respectively. Inhalation of MSPNs caused mild pulmonary toxicity with distribution of silver in various organs but the silver burdens decreased rapidly at 24-hrs post-exposure in the lung. Furthermore, inhaled MSNPs induced activation of mitogen-activated protein kinase (MAPK) signaling in the lung. In summary, single inhaled MSNPs caused mild pulmonary toxicity, which was associated with activated MAPK signaling. Taken together, our results suggest that the inhalation toxicity of MSNPs should be carefully considered at the molecular level.

Kim W.,Seoul National University | Choi I.,Wonjin Institute of Occupational and Environmental Health | Jung Y.,Seoul National University | Lee J.,Wonjin Institute of Occupational and Environmental Health | And 2 more authors.
Environmental Science and Technology | Year: 2013

Phthalate esters, which are known endocrine disruptors, are ubiquitously present throughout indoor environments. Leaching from building materials may be a major source of phthalate esters. In this study, we evaluated phthalate ester concentrations in dust samples from 64 classrooms located in 50 nursery schools and explored the critical factors affecting phthalate concentrations, especially with regard to building materials. Dust was sampled by a modified vacuuming method, and building materials were assessed using a portable X-ray fluorescence (XRF) analyzer to determine whether they contained polyvinyl chloride. Di-n-butyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), and di-isononyl phthalate (DINP) were the most frequently detected phthalates. Of these, DEHP was the most abundant phthalate, with a geometric mean of 3170 μg/g dust, and concentrations were significantly correlated with the area of polyvinyl chloride (PVC)-verified flooring. DINP, which has not been well-reported in other studies, was the second-most abundant phthalate, with a geometric mean of 688 μg/g dust, and showed a critical relationship with the number of children in the institution and the agency operating the nursery school. This is the first study to verify the sources of phthalates with an XRF analyzer and to evaluate the relationship between phthalate concentrations and PVC-verified materials. © 2013 American Chemical Society.

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