• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.51-59
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• 2018

It is difficult to determine the outdoor toxic level of hazardous chemicals that are leaked in the building, since there are no efficient ways to calculate how much percentage of the leaked chemicals is released into the outdoor atmosphere. In address to these problems, we propose a reasonable box model that can quantitatively evaluate the mass rate of the indoor chlorine leakage into the outside of the building. The proposed method assumes that the indoor chlorine leakage is fully mixed with the indoor air, and then the mixture of the chlorine and indoor air is exfiltrated into the outside of the building through effective leakage areas of the building. It is found that the exfiltration rate of the mixture of the chlorine and indoor air is strongly dependent on the temperature difference between inside and outside the building than the atmospheric wind speed. As compared with a conventional method that uses a vague mitigation factor, our method is more effective to evaluate the outdoor toxic threat zone of the chlorine that are leaked in the building, because it can consider the degree of airtight of the building in the evaluation of the threat zone.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.309-315
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• 2012

Objectives: Animal husbandry workers could be exposed to various work hazards including toxic gases, chemicals such as pesticides or organic dust. Immunological evaluation focusing on respiratory allergic hypersensitivity occurrence was under-taken for swine farm workers as a part of the study on immunologic status of dairy barn, swine confinement, and poultry farm workers. Materials and Methods: Peripheral bloods were collected from 25 workers at the year of 2001 and 12 workers at the year of 2012 from swine farms located at Gyeonggi province, Korea. Seven adults not involved with animal husbandry were recruited at the year of 2001 from the same residential area as the swine farm workers'. Level of plasma IgE and 20 respiratory allergen-specific IgE were evaluated using commercially available ELISA kit. Results: Plasma IgE level was approximately five-fold higher in the swine farm workers regardless of the sampling year than the control subjects. Plant allergens from outdoor environments such as golden rod, pigweed, Russian thistle, or ragweed were the major allergens with positive reaction(allergen specific IgE${\geq}$0.7 IU/mL) for the swine farm workers at 2001 year. Meanwhile, house dust mite(Dermatophagoides farinae, D. pteronyssinus) and cockroach, typical indoor allergens in Korea, were the major respiratory allergens for the swine farm workers at 2012 year. Conclusions: Overall, even though our results are primitive, the results suggest that immunological function of swine farm workers could be modulated toward type-2 reactivity.

• Asian Journal of Atmospheric Environment
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• v.7 no.2
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• pp.72-84
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• 2013

In the study, pollution levels of indoor polycyclic aromatic hydrocarbons (PAHs) in public facilities (vapor phase or particulate phase) were evaluated, and a health risk assessment (HRA) was carried out based on exposure scenarios. Public facilities in Korea covered by the law, including underground subway stations, funeral halls, child care facilities, internet cafes (PC-rooms), and exhibition facilities (6 locations for each type of facility, for a total of 48 locations), were investigated for indoor assessment. For the HRA, individual excess cancer risk (ECR) was estimated by applying main toxic equivalency factor (TEF) values suggested in previous studies. Among the eight public facilities, internet cafes showed the highest average $PM_{2.5}$ concentration at $110.0{\mu}g/m^3$ (range: $83.5-138.5{\mu}g/m^3$). When assuming a risk of facility exposure time based upon the results of the surveys for each public facility, the excess cancer risk using the benzo(a)pyrene indicator assessment method was estimated to be $10^{-7}-10^{-6}$ levels for each facility. Based on the risk associated with various TEF values, the excess cancer risk based upon the seven types cancer EPA (1993) and Malcolm & Dobson's (1994) assessment method was estimated to be $10^{-7}-10^{-5}$ for each facility. The excess cancer risk estimated from the TEF EPA (2010) assessment was the highest: $10^{-7}-10^{-4}$ for each facility. This is due to the 10-fold difference between the TEF of dibenzo(a,e)fluoranthene in 2010 and in 1994. The internet cafes where smoking was the clear pollutant showed the highest risk level of $10^{-4}$, which exceeded the World Health Organization's recommended risk of $1{\times}10^{-6}$. All facilities, with the exception of internet cafes, showed a $10^{-6}$ risk level. However, when the TEFs values of the US EPA (2010) were applied, the risk of most facilities in this study exceeded $1{\times}10^{-6}$.