• 한국군사과학기술학회지
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• 제25권4호
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• pp.434-442
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• 2022

Highly toxic chemical warfare agents(CWA) could be used in chemical warfare and terrorism. The protection of skin is crucial for civilians and soldiers, because the primary routes of exposure to CWA are inhalation and skin absorption. Thus, topical skin protectants(TSP) have been studied and developed in many countries to complement protective equipments. In this study, in-vitro test procedure was optimized and established using a flow-through diffusion cell system containing excised hairless mouse skin in an attempt to assess the effectiveness of various TSP formulations against nerve agent simulants. In addition, the test results on the formulations including the ingredients used in SERPACWA(Skin Exposure Reduction Paste Against Chemical Warfare Agent) and IB-1(TSP of Israel) were included, indicating that the formulations with perfluorinated compounds were more effective than the glycerin-based formulations.

• Safety and Health at Work
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• 제4권1호
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• pp.1-11
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• 2013

This review surveys the recent literature on the neurodevelopmental impacts of chemical exposures during pregnancy. The review focuses primarily on chemicals of recent concern, including phthalates, bisphenol-A, polybrominated diphenyl ethers, and perfluorinated compounds, but also addresses chemicals with longer histories of investigation, including air pollutants, lead, methylmercury, manganese, arsenic, and organophosphate pesticides. For some chemicals of more recent concern, the available literature does not yet afford strong conclusions about neurodevelopment toxicity. In such cases, points of disagreement among studies are identified and suggestions provided for approaches to resolution of the inconsistencies, including greater standardization of methods for expressing exposure and assessing outcomes.

• 한국염색가공학회지
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• 제31권4호
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• pp.258-267
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• 2019

Synthetic suede without PFCs(perfluorinated compounds) are followed by subsequent high temperature treatment. But migration fastness of synthetic suede may be reduced due to sublimation of disperse dyes that results from the high temperature treatment. Therefore, in this study, chitosan treatment was used to improve the migration fastness before polyurethane dipping process. Polyester fiber was treated with sodium hydroxide aqueous solution before chitosan processing. This samples treated with a chitosan concentration upto 0.5% were dyed and coated with PUD(polyurethane dispersion). The migration fastness was most improved at 0.35% application. This is presumably due to the fact that the chitosan may increase the dye-binding capability through intermolecular hydrogen bonding.

• Environmental Analysis Health and Toxicology
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• 제25권3호
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• pp.181-186
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• 2010

Perfluorinated Compounds (PFCs) are anthropogenic compounds found in trace amounts in many environmental compartments far from areas of production. Along with the highly persistent nature of PFCs, there are increasing concerns over the potential adverse effects of them on the ecosystems. Most of highly fluorinated compounds degrade into PFOS and PFOA that are very stable compounds hard to break down. So, in this study, we tried to determine the toxicity of PFOS and PFOA in the terrestrial invertebrate. Acute toxicity test using earthworm, Eisenia fetida, was performed according to the OECD test guideline 207 (Earthworm, Acute Toxicity Tests). In the 14 day acute toxicity tests, the highest concentration causing no mortality and the lowest concentration causing 100% mortality of PFOS were 160 and 655 mg/kg (dry weight), respectively. And the highest concentration causing no mortality and the lowest concentration causing 100% mortality were 500 and 1,690 mg/kg (dry weight), respectively in the PFOA-exposure group. 14 day-LC50 values were estimated at the level of 365 and 1,000 mg/kg (dry weight) in the PFOS and PFOA-exposed group. These results indicate that under laboratory conditions PFOS is about 3 times more toxic to earthworms than PFOA. Based on known environmental concentrations of PFOS in the soil of Korea, which occur in the 0.42~0.73 ng/L range, there is no apparent risk to terrestrial invertebrate, earthworms. However, further work is required to investigate long-term effects on these and other terrestrial organisms.

• 대한환경공학회지
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• 제36권2호
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• pp.119-126
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• 2014

본 연구에서는 과불화합물(PFOA, PFOS)과 수계에 보편적으로 존재하는 중금속(Cu, Zn, Cr, Cd, Pb, Hg)의 복합독성을 Vibrio fischeri를 이용하여 평가하였다. PFOA와 PFOS의 경우, 30 min-$EC_{50}$값이 각각 134.21 (119.54-150.68)와 235.97 (180.96-307.70) mg/L로 PFOS 보다는 PFOA의 독성이 높은 것으로 나타났다. 한편 중금속류의 독성은 $Hg^{2+}$의 독성이 가장 높았으며, 이어서 $Pb^{2+}$, $Cr^{6+}$, $Cu^{2+}$, $Zn^{2+}$, $Cd^{2+}$ 순으로 높은 독성민감도를 나타냈다. 과불화합물류와 중금속류의 복합독성의 경우, PFOA와 PFOS 모두 $Cr^{6+}$과 공존할 시 상승효과가 나타났으며, PFOA + $Zn^{2+}$, PFOS + $Zn^2$, PFOA + $Cd^{2+}$, PFOS + $Cd^{2+}$의 조합은 상가 효과를 나타냈다. 이외의 복합물질은 모두 길항작용을 하는 것으로 확인되었다. 본 연구에서는 과불화합물인 PFOA, PFOS와 중금속 복합물질들의 조합에 따른 상호작용이 상이함을 확인하였고 이 결과로부터 과불화합물과 중금속 공존할 때 수환경에 야기할 수 있는 잠재적 위해성을 예측할 수 있다.

• 한국산학기술학회논문지
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• 제16권2호
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• pp.1375-1380
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• 2015

최근 플라즈마를 이용한 과불화 화합물의 폐가스를 처리하는 기술이 발달되어져 왔다. 국내외로 여러 연구기관 및 업체에서 효율적 분해기술이 연구되어져서 그 제품들이 여러 방법들로 개선되어 왔다. 본 연구는 폐가스 분해 장치 모델 내부의 열과 유동 해석 방법을 통하여 압력 및 온도 분포를 예측하고자 한다. 해석 결과, 공기의 압력 분포 결과는 전체적으로 최대 압력이 0.975Pa과 최소 압력은 -1.037Pa로 나왔다. 공기가 입구에서 Plane 1까지 유동함에 따라 압력 값이 점점 줄고 Plane 1에서 출구까지 유동함에 따라 공기의 압력 값이 점차 증가하는 것을 볼 수 있다. 그리고 전체적으로 공기의 최대 온도와 최소 온도는 각각 $1718^{\circ}C$와 $26.07^{\circ}C$이다. 공기는 입구에서 Plane 4까지 유동함에 따라 온도가 점점 증가하였고 출구까지 유동함에 따라 공기의 온도는 줄어드는 것을 볼 수 있다. 본 연구에서의 열 유동 해석 결과를 이용하여 실제 시스템의 개발에 필요한 자료를 제공할 수 있을 것으로 사료된다.

• 상하수도학회지
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• 제36권2호
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• pp.107-119
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• 2022

The frequent detection and occurrence of micropollutants (MPs) in aquatic ecosystems has raised public health concerns worldwide. In this study, the behavior of 50 MPs was investigated in three different domestic wastewater treatment plants (WWTPs). Furthermore, the Kruskal-Wallis test was used to assess the geographical and seasonal variation of MPs in the WWTPs. The results showed that the concentrations of 43 MPs ranged from less than 0.1 to 237.6 ㎍ L^-1, while other seven MPs including 17-ethynylestradiol, 17-estradiol, sulfathiazole, sulfamethazine, clofibric acid, simvastatin, and lovastatin were not detected in all WWTPs. Among the detected MPs, the pharmaceuticals such as metformin, acetaminophen, naproxen, and caffeine were prominent with maximum concentrations of 133.4, 237.6, 71.5, and 107.7 ㎍ L^-1, respectively. Most perfluorinated compounds and nitrosamines were found at trace levels of 1.2 to 55.3 ng L^-1, while the concentration of corrosion inhibitors, preservatives (parabens), and endocrine disruptors ranged from less than 0.1 to 4310.8 ng L^-1. Regardless of the type of biological treatment process such as MLE, A2O, and MBR, the majority of pharmaceuticals (except lincomycin, diclofenac, iopromide, and carbamazepine), parabens (except Methyl paraben), and endocrine disruptors were removed by more than 80%. However, the removal efficiencies of certain MPs such as atrazine, DEET, perfluorinated compounds (except PFHxA), nitrosamines, and corrosion inhibitors were relatively low or their concentration even increased after treatment. The results of statistical analysis reveal that there is no significant geographical difference in the removal efficacy of MPs, but there are temporal seasonal variations in all WWTPs.

• 한국안전학회지
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• 제30권4호
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• pp.79-85
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• 2015

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

• Environmental Analysis Health and Toxicology
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• 제25권2호
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• pp.153-159
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• 2010

Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the principal chemicals known as perfluoroalkyl acids (PFAs). Despite the widespread use of these compounds, relatively little is known about their fate and effects. The purpose of this study was to determine the toxic effects of PFOS and PFOA on Daphnia magna. In the acute toxicity test, D. magna were exposed for 48 hours at concentrations of 0, 30, 45, 67.5, 101.25 and 151.88 mg/L PFOS, and 0, 100, 160, 225, 337.5 and 506.25 mg/L PFOA, respectively. In the case of chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 0.375, 0.75, 1.5, 3 and 6 mg/L PFOS, and 0, 1.25, 2.5, 5, 10 and 20 mg/L PFOA, respectively. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on PFOS and PFOA showed that the values of $EC_{50}$ were 50.90 mg/L and 253.47 mg/L, respectively. In the chronic test, fecundity was reduced significantly at 1.5 mg/L of PFOS and 10 mg/L of PFOA, respectively. These results indicated that PFOS is more toxic to zooplankton than PFOA, and both chemicals have some hazard demonstrates risk for acute or chronic toxicity to freshwater organism.

• Environmental Engineering Research
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• 제20권2호
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• pp.127-132
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• 2015

Perfluorooctane sulfonate (PFOS) and Perfluorooctanoic acid (PFOA) are persistent environmental pollutants, extremely stable, and possibly adversely affect human health. They are widely used in many industries and consumer goods, including sunscreen products. These substances are stable chemicals made of long carbon chains, having both lipid- and water-repellent qualities. The research objectives are (1) to find the most effective method for the preparation of semi-liquid samples by comparing solid phase extraction (SPE) and centrifugation after Pressurized liquid extraction (PLE), and (2) to determine the contamination levels of PFOS and PFOA in waterproof sunscreen samples. All sunscreen samples were analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Sunscreen samples were purchased from domestic and international brands sold in Thailand. Special chemical properties were considered for the selection of samples, e.g., those found in waterproof, sweat resistant, water resistant, and non-stick products. Considering the factors of physical properties, e.g., operation time, chemical consumption, and recovery percentage for selecting methods to develop, the centrifugation method using 2 mL of extracted sample with the conditions of 12,000 rpm and $5^{\circ}C$ for 1 hour after PLE was chosen. The highest concentrations of PFOS and PFOA were detected at 0.0671 ng/g and 21.0644 ng/g, respectively. Even though present concentrations are found at ng/g levels, the daily use of sunscreen products is normally several grams. Therefore, a risk assessment of PFOS and PFOA contamination in sunscreen products is an important concern, and more attention needs to be paid to the long-term effects on human health.