• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.75-86
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• 2020

Objectives: In this study, we assessed respiratory hazards in the working environment as the work-relatedness of occupational diseases were examined. Methods: The subjects of the study were three Korean meat roasting restaurants, one Chinese restaurant, and two cafeterias. Measurement items were total dust, respirable dust, fine dust (PM_2.5), PAHs, TVOCs, temperature, humidity, carbon monoxide, carbon dioxide, and nitrogen dioxide. Results: The concentration of total dust and respiratory dust in the restaurant was low. Most PAHs were undetectable, but some Napthalene and Acenaphthylene was detected. Thirteen kinds of PAHs were detected in one sample of roasted meat, and Benzo(a)pyrene was 1.496 ㎍/㎥. PM_2.5, TVOCs, CO, and CO₂ were instantaneously high, but the average concentration was low. NO₂ was not detected. Conclusions: The results show that harmful substances such as PM_2.5, PAHs, CO, and TVOCs were generated in the air in the catering industry. When roasting meat, Benzo(a)pyrene, a carcinogen related to lung cancer, was generated among PAHs. Lung cancer can occur when working for a long time in such a working environment. Therefore, it is necessary to improve the working environment for the health of restaurant workers, and it is necessary to evaluate the concentration of harmful substances by cooking method through further research.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.577-586
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• 2016

Hazardous air pollution caused by heavy metals in the air is at a serious level. Although manganese(Mn), one of the heavy metals, is a non-carcinogenic substance, it has a harmful influence on the human body. It is partially measured because automatic monitoring technologies have not yet be fully established. We introduced a statistical model for the daily concentration of manganese. Incorporating a linkage between Mn and meteorology, the proposed model is formulated in way to identify meteorological effects and to allow for seasonal trends, enabling not only accurate measurement of manganese concentration, but also information about the evaluation on a Hazard Quotient (non-cancer risk).

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.31-36
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• 2019

Concrete is a material generally used to build structures and it is exposed to various environment conditions. In particular, a medium such as water lets noxious factors flow into concrete, causing a lot of damage. Therefore, different kinds of materials are being developed to increase the durability of concrete. Among such materials, silane and siloxane compound are known to have a high utilization as an absorption inhibitor. However, if aged or deteriorated reinforced concrete is treated with those compounds, they easily come off the concrete and lose their function since the basic material is weak. This study conducted an experiment to provide concrete with both an absorption-inhibiting effect and surface strengthening by using melamine-formaldehyde resins that are surface-treated with siloxane compound. In addition, a study on the porosity and surface hardness characteristics of a concrete was conducted to check the absorption-inhibiting effect and surface strengthening.

• Journal of the Korea Safety Management & Science
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• v.25 no.1
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• pp.7-14
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• 2023

We attempted to provide an overview of the laws and current state of the 3D printing industry in South Korea and around the world, using the annual industry surveys and the Wohler report. Additionally, we reviewed articles relating to the potential exposure to hazards associated with 3D printing using metal materials. In South Korea, there were 406 3D printing-related businesses, employing 2,365 workers, and the market size was estimated at 455.9 billion won in 2021. Globally, the average growth rate of the 3D printing industry market over the past 10 years was 27.4%, and the market size was estimated at $11.8 billion in 2019. The United States had the highest cumulative installation ratio of industrial 3D printers, followed by China, Japan, Germany, and South Korea. A total of 6,168 patents related to 3D printing were registered in the US between 2010 and 2019. Harmful factors during metal 3D printing was mainly evaluated in the powder bed fusion and direct energy deposition printing types, and there is a case of material extrusion type with metal additive filaments. The number, mass, size distribution, and chemical composition of particles were mainly evaluated. Particle concentration increases during the opening of the chamber or post-processing. However, operating the 3D printer in a ventilated chamber can reduce particle concentration to the background level. In order to have a safe and healthy environment for 3D printing, it is necessary to accumulate and apply knowledge through various studies.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.134-138
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• 2015

BACKGROUND: In recent years, several researchers have focused on odour control methods to remove the harmful chemicals from chemical accidents and incidents. The present work deals with the system development of the hazardous. METHODS AND RESULTS: For on-site removal of hazardous gaseous materials from chemical accidents, mobile vortex wet scrubber was designed with water vortex process to absorb the gas into the water. The efficiency of the mobile vortex wet scrubber was evaluated using water spray and 25% ammonia solution. The inlet air velocity (gas flow rate) was according to the damper angle installed within the hood and with increase of gas flow rate, consequently the absorption efficiency was markedly decreased. In particular, when 25% ammonia solution was exposed to the hood inlet for 30 min, the water pH within the scrubber was changed from 7 to 12. Interestingly, although the removal efficiency of ammonia gas exhibited approximately 80% for 5 min, its efficiency in 10 min showed the greatest decrease with 18%. Therefore, our results suggest that the ammonia gas may be absorbed with the driving force of scrubbing water in water vortex process of this scrubber. CONCLUSION: When chemical accidents are occurred, the designed compact scrubber may be utilized as effective tool regarding removal of ammonia gas and other volatile organic compounds in the scene of an accident.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.150-158
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• 2020

Objective: This study is designed to measure the concentration of DBPs (disinfection by-products) in pool water and in air and to estimate the carcinogenic potential through the evaluation of inhalation exposure. Methods: The subjects were six indoor swimming pools with many users in Gwangju. Samples of pool water and indoor air were taken every one month from August 2018 to August 2019 and analyzed for eight swimming pool standards. Three-liter air samples were collected and the VOCs were analyzed using GC/MS directly connected to thermal desorption. Results: pH was 6.8-7.5 and the concentration of free residual chlorine in pool water was 0.40-0.96 ?/ℓ. Physicochemical test items such as KMnO₄ consumption and heavy metal items such as Aluminum met existing pool hygiene standards. No VOC materials were detected except for the DBPs. The concentration of THMs in the pool water was 11.05-41.77 ㎍/L and the THMs mainly consist of Chloroform (63-97%) and BDCM (3-31%). The concentration of indoor air THMs is 13.24-32.48 ㎍/㎥ and consists of Chloroform. The results of carcinogenic assessment of chloroform in the indoor swimming pool via inhalation exposure were 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA. Conclusions: The concentration of THMs in the pool water is 11.05-41.77 ㎍/L, most of which is chloroform. In addition, the concentration of indoor air THMs is 13.24-32.48 ㎍/㎥. The result of carcinogenic assessment of chloroform was 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA.