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Park D.,Korea University | Kim S.,Wonjin Institute for Occupational and Environmental Health | Ha K.,Changwon National University
Aerosol and Air Quality Research | Year: 2012

Alkanolamines or ethanolamines - triEA (TEA), di-EA (DEA), and mono-EA (MEA) - may be used in water-soluble metalworking fluids to stabilize pH or inhibit corrosion. The objectives of this study were to compare EAs levels from air and used fluid bulk among the various metalworking operations, and to examine the relationship not only between aerosol concentration and total airborne EA levels, but also between aerosol levels and the proportion of each type of EA in the total EA in air and fluid bulk. The EA from air and fluid bulk collected from machining operations were quantified by ion chromatography. Airborne EA were taken into de-ionized water (DI) using an impinger. Average aerosol levels were 1.15 mg/m3 for machining and 0.84 mg/m3 for grinding operations. The highest aerosol and total EA levels were for (i) washing operations (4.06 mg/m3 and 1.33 mg/m3, respectively), where compressed air was frequently used to clean metal machine parts, and (ii) individual tanks (1.83 mg/m3 and 2.31 mg/m3, respectively). Airborne MEA was detected in all samples (n = 53), while TEA was not detected in any air samples (n = 13) taken from areas without machining operations. Machining operations showed a significant relationship between aerosol and total EA levels (n = 21, R2 = 0.74). The EA content ratio (EAR: level of each EA in air as a% of total EA in air)/(level of each EA in bulk fluid as a% of total EA in bulk fluid) showed a significant association with the aerosol level, but showed a different pattern according to the EA type. A negative exponential relationship was observed for MEAR (n = 9, R2 = 0.64), with MEAR being greater than "1" at low aerosol concentrations (< 1 mg/m3). In contrast, TEAR increased linearly with increasing aerosol levels, reaching almost "1" when the aerosol concentration was higher than 2.0 mg/m3. The relationship between fluid EA formulation, airborne EA levels, and aerosol levels in machining operations was found to be quite different according to the type of EA. © Taiwan Association for Aerosol Research. Source

Hwang S.H.,Ajou University | Lee I.M.,Inha University | Lee Y.K.,Wonjin Institute for Occupational and Environmental Health | Park J.I.,Soonchunhyang University | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2013

We characterize the monthly variation in (1 → 3)-β-d-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-d-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-d-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-d-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105 ± 1,893 pg/m3) and in the spring (5,458 pg/m3). The highest concentration of (1 → 3)-β-d-glucan occurred in the spring, particularly in May. © 2013 Springer Science+Business Media Dordrecht. Source

Kim S.-B.,Wonjin Institute for Occupational and Environmental Health | Yoon C.-S.,Seoul National University | Park D.,Korea University
Safety and Health at Work | Year: 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group (HOCH2CH2), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from 0.19 mg/m2· min at 23.5 °C to 8.04 mg/m2·min at 60 °C. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was 0.45 mg/m 3 in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations. Copyright © 2010 by Safety and Health at Work (SH@W). Source

Park D.,Korea University | Ryu S.,Korea University | Kim S.,Wonjin Institute for Occupational and Environmental Health | Byun H.,Seoul National University | And 2 more authors.
International Journal of Occupational and Environmental Health | Year: 2013

Background: Municipal workers handling household waste are potentially exposed to a variety of toxic and pathogenic substances, in particular airborne bacteria, gram-negative bacteria (GNB), and fungi. However, relatively little is known about the conditions under which exposure is facilitated. Methods: This study assessed levels of airborne bacteria, GNB, and fungi, and examined these in relation to the type of waste-handling activity (collection, transfer, transport, and sorting at the waste preprocessing plant), as well as a variety of other environmental and occupational factors. Airborne microorganisms were sampled using an Andersen single-stage sampler equipped with agar plates containing the appropriate nutritional medium and then cultured to determine airborne levels. Samples were taken during collection, transfer, transport, and sorting of household waste. Multiple regression analysis was used to identify environmental and occupational factors that significantly affect airborne microorganism levels during waste-handling activities. Results: The "type of waste-handling activity" was the only factor that significantly affected airborne levels of bacteria and GNB, accounting for 38% (P50.029) and 50% (P50.0002) of the variation observed in bacteria and GNB levels, respectively. In terms of fungi, the type of waste-handling activity (R250.76) and whether collection had also occurred on the day prior to sampling (P<0.0001, R250.78) explained most of the observed variation. Given that the type of waste-handling activity was significantly correlated with levels of bacteria, GNB, and fungi, we suggest that various engineering, administrative, and regulatory measures should be considered to reduce the occupational exposure to airborne microorganisms in the waste- handling industry. © W. S. Maney & Son Ltd 2013. Source

Lee Y.-H.,Korea University | Cha E.S.,Korea University | Moon E.K.,Korea University | Kong K.A.,U.S. Center for Disease Control and Prevention | And 3 more authors.
Journal of Preventive Medicine and Public Health | Year: 2010

Objectives: Exposure assessment is a major challenge faced by studies that evaluate the association between pesticide exposure and adverse health outcomes. The objective of this study was to investigate the reliability of information that farmers self-report regarding their pesticide use. Methods: Twenty five items based upon existing questionnaires were designed to focus on pesticide exposure. In 2009, a self-administrated survey was conducted on two occasions four weeks apart among 205 farmers residing in Gyeonggi and Gangwon provinces. For a reliability measure, we calculated the percentage agreement, the kappa statistics and the intraclass correlation coefficient (ICC) between the two reports according to the characteristics of the subjects. Results: Agreement for ever-never use of any pesticide was 96.4% (kappa 0.61). For both 'years used' and 'age at the first use' of overall pesticides, high agreement was obtained (ICC: 0.88 and, 0.78, respectively), whereas those of 'days used' and 'hours used' were relatively low (ICC: 0.42 and, 0.66, respectively). The kappa value for the use of personal protective equipment ranged from 0.46 to 0.59, and hygiene activities came out at 0.19 to 0.37. The agreement for individual pesticide use ranged widely and there was relatively low agreement due to the low response rates. The reliability scores did not significantly vary according to gender, age, the education level, the types of crop or the years of farming. Conclusions: Our results support mat carefully designed, self-reported information on ever-never pesticide use among farmers is reliable. However, the reliability of data on individual pesticide exposure may be unstable due to low response rates and needs to be refined. Source

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