• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.14-17
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• 2024

Objectives: This is a case of air exposure assessment conducted after researchers complained of headaches and odor due to residual substances from fire extinguishing agents spread throughout the laboratory due to a malfunction of the fire extinguishing facility. Methods: A component analysis was conducted on the residual substances of a fire extinguishing agent spread in a laboratory using Py-GC-MS (pyrolysis gas chromatography mass spectrometry) at the research institute's own central equipment research center. As a result of the component analysis, several types of substances were detected. Among these, five types of substances subject to work environment measurement in the aromatic hydrocarbon series, which can affect headaches and odor, were selected as substances subject to exposure assessment in the air, and the measurement and analysis methods of the target substances were conducted in accordance with the KOSHA Guide for each substance. Conclusions: The measurement results showed that all 5 types of substances were not detected at locations A, B, and C. This is believed to be the result of the residual substances in the fire extinguishing agent being measured when approximately two months had elapsed after being exposed to the test bench, and the substances already exposed had volatilized and disappeared. In this survey, it is believed that the measurement process is more important than the measurement results.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.196-204
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• 2013

Objectives: The purpose of this study is to analyze the number and influence factors of asbestos fibers in the air of farmhouses with asbestos cement slate roofing, as well as in rainwater per unit area of the asbestos cement slate roofing. Methods: At a distance of 1 m from the end of asbestos cement slate roofing in 20 farmhouses, the asbestos fiber in the air was collected three times on a clear day downwind from the prevailing wind. Rainwater falling from the slate roofing was collected four times with a 1.05-m rainwater pipe on a rainy day at the 20 farmhouses, filtered with a MCE filter, and analyzed with a phase contrast microscope. Results: The geometric mean of the number of asbestos fibers in the air of farmhouses with slate roofing was 0.11 fiber/L, and no samples exceeded the recommended standard of 10 fiber/L. As a result of multiple regression analysis, a factor which gave a significant influence to the asbestos fiber content in the air was the gross area of slate roofing at the target farmhouses. The number of asbestos fibers included in rainwater collected per 1 m2 of slate roofing was 1,753 fiber/$L{\cdot}m2$. As a result of multiple regression analysis, the number of asbestos fibers contained in rainwater per 1 m2 of slate showed a significantly higher tendency as the year of slate roofing installation at the target farmhouses receded. Conclusions: It was confirmed for the first time in Korea that asbestos from asbestos cement slate roofing scatters into the air.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.1
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• pp.31-42
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• 2007

Recently, concerns regarding indoor air quality in offices have continued to increase. Thirty offices in five metropolitan commercial buildings were surveyed from February to April 2004. Sampling was performed during normal business hours. Thermal comfort factors such as temperature and relative humidity, carbon dioxide ($CO_2$), carbon monoxide (CO), formaldehyde (HCHO), respirable dust, $PM_{10}$ were sampled and analyzed to determine the mean, standard deviation, range, and correlation for each of those parameters. The data was then compared to office as standard of Ministry of Labor, and guideline applicable to the indoor environment. The results represented that the temperature was slightly higher than the standard of American Society of Refrigerating and Air-Conditioning Engineers (ASHRAE), the relative humidity was lower that the standard of ASHRAE. The range of the 8-TWA concentration of $CO_2$ was 639 ~ 786 ppm, but 33.3% of the total thirty offices exceeded the 1000 ppm as ceiling concentration. The concentration of CO was less than 3 ppm, which was similar to that of offices in Japanese. The mean concentration of formaldehyde was 0.032 ppm, and only 2 % of total samples (193) exceeded the 0.1 ppm, standard of formaldehyde in office air. The concentration of respirable dust and $PM_{10}$ was not exceeded the standard of those parameters, $150{\mu}g/m^3$. The concentration of those parameters in the office air was statistically correlated.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.188-193
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• 1993

Toluene in air and blood and hippuric acid in urine were checked for the 41 female workers who are exposed to toluene and have normal liver function in shoe making factories in July, 1993. Toluene in air was sampled with charcoal by personal air sampler at least 4 times and analyzed by gas chromatography. At the end of shift, blood and spot urine were collected with a vacuum tube containing EDTA and a polyethylene bottle for detecting blood toluene and urine hippuric acid and analyzed by gas chromatography and high performance liquid chromatography. Means of air and blood toluene and urine hippuric acid concentrations were 34.35ppm, 0.360mg/L, and 1.78g/g creatinine, respectively. Toluene in air showed a good correlation with hippuric acid in urine(r=0.4503) and toluene in blood(r=0.4596). The hippuric acid in urine and toluene in blood corresponded 10 exposure of 100ppm toluene in air were 2.628g/g creatinine and 0.481mg/L. Blood toluene and urine hippuric acid expected ratio were not correlated to the obesity index and working duration, however increased with age.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.201-209
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• 2016

Many atmospheric pollutants including chemical agents, house dust, and microorganisms cause building-related illnesses through respiration in humans. This study was conducted to analyze the profiles of microbial pollutants in air purifiers used in home, office and playschool. Dominant eleven species of microorganisms were isolated and identified in environmental air and air purifiers. Among them, Staphylococcus sp., Micrococcus sp. and Bacillus sp. are the most dominant species. By phylogenetic analysis of the 16S rRNA gene, the dominant bacteria were identified as Staphylococcus epidermidis, Micrococcus luteus and Bacillus epidermidis, respectively. It has been known that these bacterial species are closely related with food spoilage and human infectious disease. Thus, these results indicate that microbial pathogens related with human illnesses through respiration will be contaminated in air purifiers and also need to develop a method to control those of pathogens for human health.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.163-173
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• 2020

Objectives: The study was evaluated exposure variation and daily absorption level of cadmium, lead concentration of ambient air of monthly data from 1999 to 2017 for main exposure factor in outdoor workers. Methods: Based on the monthly data from 'The annual report of air quality in Korea from 1999 to 2018' in 'Air Korea' website in the Korean Ministry of Environment. The monthly data of PM_2.5, PM₁₀, cadmium, lead concentration of ambient air were recalculated to average, minimum, and maximum. And these data were combined to Asian-dust exposure data from 'The annual report of Asian-dust·smog in 2017' of National Institute of Meteorological Sciences in Korea. Results: Geometric mean(minimum-maximum) concentration in ambient air of monthly data were 0.0017 (ND-0.2015) mg/㎥ in cadmium and 0.0467(ND-0.8554) mg/㎥ in Pb from 1999 to 2017. Both of Cd and Pb concentration in ambient air showed the highest concentration in January and the lowest in August among annual variation from 1999 to 2017. PM₁₀ and PM_2.5 level showed the highest in March(PM₁₀) and February (PM_2.5) the lowest in August both of PM₁₀ and PM_2.5. Discussion: Based on exposure data and prior reports, daily Cd absorption was estimated to 0.013(ND-1.511) mg/day from respiration and 1.89 mg/day from daily food(25.2 mg/day of daily Cd intake). In case of Pb, daily absorption was estimated to 0.350(ND-6.416) mg/day from respiration and 1.38-1.71 mg/day from daily food intake. Conclusion: Cd and Pb with Asian-dust have high influential factor to increase the Cd and Pb exposure at Winter and Spring season in outdoor workers.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.415-419
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• 2012

To know proper drying condition for making a safe Sunsik, uncooked food, microbial and physicochemical characteristics of cereal dried by hot-air drying was investigated. As moisture content of 3 Sunsik samples was reduced to about 8%, protein, carbohydrate, fat and ash content of those was increased. But approximate composition of black bean, black rice and glutinous millete and black bean showed little changes during hot-air drying (30, 40, $50^{\circ}C$). Lightness (L value), redness (a value) and yellowness (b value) was increased after hot-air drying. In case of black rice and glutinous millet, b value and L value wasn't changed individually. When we measured a texture for 3 kinds of raw cereal for, hardness of dried cereals was lower than raw cereals. Hardness of dried cereals was increasd as drying temperature was increased. As results of mocrobiologicl experiment for 3 kinds of sunsik on hot-air drying conditions, total cell count was reduced 2 log - 3 log and other pathogenic microorganism wasn't detected except B. cereus.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.112-124
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• 1999

The purposes of this study were to provide the data for composition of ethylene glycol ethers and 2-ethoxyethyl acetate(EEA) exposure assessment of workers in various industrial operations. In this study, 80 thinners were analyzed to identify their composition and the air concentration of 2-ethoxyethyl acetate(EEA) and urinary 2-ethoxyacetic acid(EAA) were measured. In this study the subjects were the total of 183 drawn from 98 workers who were occupationally exposed to EEA and 85 workers who were not. The results were as follows: 1. There were found average 4.2 components in each thinner. 2. There were 90 components(26.9%) in ethylene glycol ethers of total of 334 detected organic solvents 3. Ethoxyethyl acetate, ethoxyethanol, buthoxyethanol, methoxy-ethanol were found in 30(37.5%), 27(33.8%), 19(23.8%), 2thinners(2.5%), respectively and their contents were average 18.5%. 4. Benzene was found 8 thinners(10.0%) of the total 80 surveyed. 5. In the electronic painting workers EEA exposure concentration was the highest, as showed 2.88ppm(0.01~15.1ppm), cases of exceeded threshold limit value(TLV=5ppm) were 7(10.6%) workers among the total of 98 exposed workers. 6. The geometric mean of urinary EEA in exposed workers was 1.61 mg/gcreatinine, and was higher than that of workers who were not exposed. In the electronic painting workers and offset printers, the geometric mean of urinary EAA was the highest showing 2.8 mg/gcreatinine. 7. The correlation coefficient between urinary concentration of EAA and air concentration of EEA was 0.90(P<0.05). The present results suggest that composition of ethylene glycol ethers in thinners must be evaluated when industrial hygiene surveys and biological monitoring are performed.

• Advances in environmental research
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• v.1 no.1
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• pp.57-68
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• 2012

Recent studies showed that air pollution is a risk factor for hospitalization for chronic obstructive pulmonary disease (COPD). However, there is limited evidence to suggest which subpopulations are at higher risk from air pollution. This study was undertaken to examine the modifying effect of specific secondary diagnosis (including hypertension, diabetes, pneumonia, congestive heart failure) on the relationship between hospital admissions for COPD and ambient air pollutants concentrations. Hospital admissions for COPD and ambient air pollution data for Taipei were obtained for the period from 1999-2009. The relative risk of hospital admissions for COPD was estimated using a case-crossover approach. None of the secondary diagnosis we examined showed much evidence of effect modification.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.1 no.1
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• pp.8-15
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• 1991

In order to visualize the distribution of workplace of which mixed solvent level in air exceeded the TLV of 1.0 (ACGIH), 17 thinners used in 44 painting workplaces were analysed with gas chromatography, and their levels in air were compaired with. 1. For detection rate of solvents in thinner was highest in case of toluene (76.4%), and decreased in orders of xylene (70.6%), methylisobutyl ketone (35.3%), acetone (35.3%), methyl ethyl ketone (23.5%), isopropylacohol (17.6%), n-hexane (17.6%), styrene (11.8%), and ethylacetate (11.8%). Average number of solvents detected was 3.0. 2. Detection rates of organic solvent by component category was highest in cases of aromatic hydrocarbons (52.9%), and decreased in orders of ketones (31.4%), alcohols (5.9%), n-hexane (5.9%) and esters (3.9%). The rate by regulatory category, the second category component was detected in 93.9% of total. 3. There was significant correlation (r=0.929, p<0.01)between detection rates of solvents in thinner and in air. 4. Among the total of 44 painting workplace, the rate of them of which level of mixed solvents in air was exceeded was highest in case of aromatic hydrocarbons (29.5%), and decreased in orders of ketones (6.8%), alcohol (2.3%), n-hexane (2.3%), and was highest in guitar painting (71.4%) workplace in case of aromatic hydrocarbons by component category.