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Study on the Enumeration of Legionella in Environmental Water Samples Using Real-time PCR (Real-time PCR을 이용한 환경 중 물 시료의 레지오넬라 분석법 연구)

  • Lee, Jung-Hee;Park, Myoung-Ki;Kim, Yun-Sung;Yun, Hee-Jeong;Lee, Chang-Hee;Jeong, Ah-Yong;Yoon, Mi-Hye
    • Journal of Environmental Health Sciences
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    • v.45 no.5
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    • pp.511-519
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    • 2019
  • Objectives: The standard method for the enumeration of environmental Legionella is culturing, which has several disadvantages, including long incubation and poor sensitivity. The purpose of this study is to demonstrate the usefulness of real-time PCR and to improve the standard method. Methods: In 200 environmental water samples, a real-time PCR and culture were conducted to detect and quantify Legionella. Using with the results of the survey, we compared the real-time PCR with the culture. Results: Each real-time PCR assay had 100% specificity and excellent sensitivity (5 GU/reaction). In the culture, 36 samples were positive and 164 samples were negative. Based on the results of the culture, real-time PCR showed a high negative predictive value of 99%, 35 samples were true positive, 105 samples were true negative, 59 samples were false positive and one sample was a false negative. Quantitative analysis of the two methods indicated a weak linear correlation ($r^2=0.29$, $r^2=0.61$, respectively). Conclusions: Although it is difficult to directly apply quantitative analysis results of real-time PCR in the enumeration of environmental Legionella, it can be used as a complementary means of culturing to rapidly screen negative samples and to improve the accuracy of diagnosis.

Assessment of Environmental Pollution for Streams of Andong City in Gyeongbuk Province Using Invertebrate Biomarker and Chemical Residual Analysis (무척추동물 생체지표와 화학잔류량 분석을 통한 경북 안동지역내 하천들의 환경오염 평가)

  • Ryoo Keon-Sang;Choi Jong-Ha;Kim Young-Gyun;Cho Sung-Hwan;Lee Hwa-Sung
    • Journal of Environmental Science International
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    • v.14 no.6
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    • pp.583-596
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    • 2005
  • Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or univestigated pollutants in this study.

PCDD/Fs Levels and Congener Pattern Characteristics in Stack Gas and Fly Ash from Waste Incinerators, Environmental Media, Food, and Human Tissues: An Overview (국내 폐기물소각시설 배출가스와 소각재, 환경 매질, 식품 및 인체에서 검출된 다이옥신 농도수준 및 이성질체 유형 특성)

  • Kim Su-Jin;Park Soyoung;Choi Seung-Pil;Lee Dong Soo
    • Environmental health and toxicology
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    • v.19 no.1
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    • pp.1-24
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    • 2004
  • Since dioxins became a serious concern in Korea, a significant number of investigations have been conducted to address diverse issues related to dioxins. However, the results have not been organized for ready access and use. The principal purposes of the work were to ⅰ) provide an archive of dioxin researches in Korea and ⅱ) give an overview of dioxin contamination. The focus of this work was placed on the contamination levels and characteristics concerning the waste incinerators emissions, environmental media, and biological samples(fishes/shellfishes, foods, and human body). Principal component analysis was conducted to identify common and/or unique features and the important variables associated with the congener patterns. From a comprehensive search of academic journals, research and monitoring project reports, dissertations, and periodicals of other forms, a total of 115 counts were found that met the purposes of this study. The contamination levels of various samples were summarized and compared to those reported in foreign literatures. The congener patterns varied largely with environmental media and distinguished particularly by OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF for the samples within the same media. The proximity to emission sources differentiated the congener patterns in air and soil samples by the fraction of OCDD.

Evaluation of Alternative Acute Toxicity Test Method with Daphnia magna (Toxkits에 의한 물벼룩 급성독성시험방법의 제도적용 적합성 평가)

  • Kim, Jongmin;Shin, Kisik;Lee, Jungseo;Lee, Taekjune
    • Journal of Korean Society on Water Environment
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    • v.33 no.2
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    • pp.181-186
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    • 2017
  • This paper aimed to evaluate the results of alternative acute toxicity test on 83 wastewater samples. Each sample was tested by traditional method (using laboratory cultured D. magna as a test organism) and alternative method (using Toxikit which can be purchased from a specialized company). The relationship between Lab. culture toxicity and Toxkits toxicity indicated good relation ($r^2=0.84$, p<0.01, n = 83). Number of samples which showed a small difference of lower than 0.5 between two test methods were 52 and they account for 63 percent of collected samples. In addition, these 52 samples had a lower average toxicity of TU 0.5 (Lab. culture method) and TU 0.45 (Toxkits method). Whereas samples which indicated big difference of test results between two methods, had a tendency to show higher toxicity. From these results, alternative toxicity test method could be applied to the official test method, if samples would have a lower toxicity less than TU 2. Also, Toxikit standard toxicant test results indicated $EC_{50}$ values between 0.93 and 1.68 mg/L and these results were considered as valid for quality control standard.

Health Risks Assessment in Children for Phthalate Exposure Associated with Childcare Facilities and Indoor Playgrounds

  • Kim, Ho-Hyun;Yang, Ji-Yeon;Kim, Sun-Duk;Yang, Su-Hee;Lee, Chung-Soo;Shin, Dong-Chun;Lim, Young-Wook
    • Environmental health and toxicology
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    • v.26
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    • pp.8.1-8.9
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    • 2011
  • Objectives: This study assessed the health risks for children exposed to phthalate through several pathways including house dust, surface wipes and hand wipes in child facilities and indoor playgrounds. Methods: The indoor samples were collected from various children's facilities (40 playrooms, 42 daycare centers, 44 kindergartens, and 42 indoor-playgrounds) in both summer (Jul-Sep, 2007) and winter (Jan-Feb, 2008). Hazard index (HI) was estimated for the non-carcinogens and the examined phthalates were diethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dibutyl-n-butyl phthalate (DnBP), and butylbenzyl phthalate (BBzP). The present study examined these four kinds of samples, i.e., indoor dust, surface wipes of product and hand wipes. Results: Among the phthalates, the detection rates of DEHP were 98% in dust samples, 100% in surface wipe samples, and 95% in hand wipe samples. In this study, phthalate levels obtained from floor dust, product surface and children's hand wipe samples were similar to or slightly less compared to previous studies. The $50^{th}$ and $95^{th}$ percentile value of child-sensitive materials did not exceed 1 (HI) for all subjects in all facilities. Conclusions: For DEHP, DnBP and BBzP their detection rates through multi-routes were high and their risk based on health risk assessment was also observed to be acceptable. This study suggested that ingestion and dermal exposure could be the most important pathway of phthalates besides digestion through food.

QA/QC for 222Rn analysis in groundwater (지하수 중 222Rn 분석을 위한 정도관리)

  • Jeong, Do Hwan;Kim, Moon Su;Kim, Hyun Koo;Kim, Hye Jin;Park, Sun Hwa;Han, Jin Seok;Ju, Byoung Kyu;Jeon, Sang Ho;Kim, Tae Seung
    • Analytical Science and Technology
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    • v.26 no.1
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    • pp.86-90
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    • 2013
  • $^{222}Rn$ concentrations in the groundwater samples without standard material due to the short half-life (3.82 day) were measured through the establishment of the counting efficiency of LSC (Liquid Scintillation Counter) using a standard source of $^{226}Ra$. This study for Quality Assurance/Quality Control (QA/QC) of $^{222}Rn$ analysis was performed to analyze blank samples, duplicate samples, samples of groundwater sampling before and after. In-situ blank samples collected were in the range of 0.44~6.28 pCi/L and laboratory samples were in the range of 1.66~4.95 pCi/L. Their correlation coefficient was 0.9691 and the source contamination from sampling, migration and keeping of samples were not identified. The correlation coefficient between original and duplicate samples from 65 areas was 0.9987. Because radon is an inert gas, in case of groundwater sampling, it is considered to affect the radon concentration. We analyzed samples separately by groundwater sampling before and after using distilled water, but there is no significant difference for $^{222}Rn$ concentrations in distilled waters of two types.

Evaluation and application of pretreatment methods for pharmaceuticals and personal care products in the solid phase of sewage samples (하수처리시설 고상시료 중 잔류의약물질 분석을 위한 전처리법 평가 및 적용)

  • Park, Junwon;Kim, Changsoo;Ju, Byoungkyu;Lee, Wonseok;Chung, Hyenmi;Jeong, Dong-Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.6
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    • pp.559-572
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    • 2018
  • The aim of this study was to evaluate pretreatment methods for 27 pharmaceuticals and personal care products (PPCPs) in various sewage samples using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and online solid-phase extraction with LC-MS/MS. Extraction efficiencies of PPCPs in the solid phase under different experimental conditions were evaluated, showing that the highest recoveries were obtained with the addition of sodium sulfate and ethylenediaminetetraacetic acid disodium salt dehydrate in acidified conditions. The recoveries of target compounds ranged from 91 to 117.2% for liquid samples and from 61.3 to 137.2% for solid samples, with a good precision. The methods under development were applied to sewage samples collected in two sewage treatment plants (STPs) to determine PPCPs in liquid and solid phases. Out of 27 PPCPs, more than 19 compounds were detected in liquid samples (i.e., influent and effluent) of two STPs, with concentration ranges of LOQ-33,152 ng/L in influents and LOQ-4,523 ng/L in effluents, respectively. In addition, some PPCPs such as acetylsalicylic acid, ibuprofen, and ofloxacin were detected at high concentrations in activated sludge as well as in excess sludge. This methodology was successfully applied to sewage samples for the determination of the target compounds in STPs.

A combined approach to evaluate activity and structure of soil microbial community in long-term heavy metals contaminated soils

  • Wang, Tianqi;Yuan, Zhimin;Yao, Jun
    • Environmental Engineering Research
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    • v.23 no.1
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    • pp.62-69
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    • 2018
  • In the present study, long-term heavy metals (HMs) contaminated soil samples from a well-known Pb/Zn smelting area in the southwest of China were collected, and physicochemical and biological characteristics of these samples were evaluated. Soil samples contained different concentrations of HMs, namely Pb, Zn, Cu, and Cd. Enzyme activity analyses combined with microcalorimetric analysis were used for soil microbial activity evaluation. Results showed that two soil samples, containing almost the highest concentrations of HMs, also shared the greatest microbial activities. Based on correlation coefficient analysis, high microbial activity in heavily HMs contaminated soil might be due to the high contents of soil organic matter and available phosphorus in these samples. High-throughput sequencing technique was used for microbial community structure analysis. High abundance of genera Sphingomonas and Thiobacillus were also observed in these two heavily contaminated soils, suggesting that bacteria belonging to these two genera might be further isolated from these contaminated soils and applied for future studies of HMs remediation. Results of present study would contribute to the evaluation of microbial communities and isolation of microbial resources to remediate HMs pollution.

Assessment of potential environmental impact from fly ash landfill (국내 석탄회 육상매립의 오염 잠재성 평가)

  • Lee, Sang Hoon
    • Journal of Environmental Impact Assessment
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    • v.8 no.4
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    • pp.25-35
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    • 1999
  • Fly ash, by-product from coal fired power station, has long been regarded as a potential contamination source for heavy metals and inorganics due to their enriched concentrations and associations with particle surface. Feed coal and fly ash samples were collected from two power stations; Yongdong deliang with domestic anthracite coals and Boryong with imported bituminous coals. The coal and fly ash samples were analyzed for chemical composition and mineral components, using XRF and XRD. Batch leaching experiments were conducted by agitating samples with deionised water for 24 hours. Anthracite coals are generally higher in Al and Si contents than bituminous coals. This is due to the higher ash contents of the anthracite coal than bituminous coal. The chemistry of the two fly ash samples shows broadly similar compositions each other, except for the characteristically high contents of Cr in anthracite coal fly ash. Leaching experiments revealed that concentrations of metals gradually decreased with leachings in general. However, measurable amounts of metals were present in the effluent from weathered ash and the samples subjected to the leaching procedure. These metals are likely to indicate that the metals in fly ash were incorporated into glass fraction as well as associated with particle surface of samples. Dissolution of aluminosilicate glass would control releasing heavy metals from fly ash as weathering progresses during landfill with implication of possible groundwater contamination through fly ash landfill.

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Occurrence and Molecular Differentiation of Environmental Mycobacteria in Surface Waters

  • Lee, Eun-Sook;Lee, Mok-Young;Han, Sun-Hee;Ka, Jong-Ok
    • Journal of Microbiology and Biotechnology
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    • v.18 no.7
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    • pp.1207-1215
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    • 2008
  • To investigate the occurrence and species diversity of mycobacteria in waters, surface water samples were collected monthly from the Han River and tap water samples at the terminal sites of the distribution system. Mycobacteria in each water sample were isolated by decontamination using cetylpyridinium chloride (CPC) and cultivation on Middlebrook 7H10 agar, and then identified by polymerase chain reaction-restriction fragment length polymorphism analysis (PRA) and sequencing of the 65-kDa heat-shock protein gene (hsp65 gene). Mycobacteria were detected in 59% of the surface water samples and 26% of the tap water samples. Over half of the 158 isolates could not be identified by hsp65 PRA and gene sequencing, and several identification discrepancies were observed between the two methods. The most frequently isolated species was Mycobacterium gordonae in surface water and M. lentiflavum in tap water. M. avium complex (MAC), the most important pathogen among environmental mycobacteria, was detected in the surface water samples but not found in the tap water samples. The result demonstrated that water is an important environmental source of mycobacteria and the combined application of hsp65 PRA and sequencing was more reliable than hsp65 PRA alone to accurately identify mycobacteria present in water.