• Title/Summary/Keyword: Background Concentration

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Study of Naturally Occurring Radioactive Material Present in Deep Soil of the Malwa Region of Punjab State of India Using Low Level Background Gamma-Ray Spectrometry

  • Srivastava, Alok;Chahar, Vikash;Chauhan, Neeraj;Krupp, Dominik;Scherer, Ulrich W.
    • Journal of Radiation Protection and Research
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    • v.47 no.1
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    • pp.16-21
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    • 2022
  • Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region. Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of 60Co was used in the present work. Data were evaluated with Genie-2000 software. Results and Discussion: Mean activity concentrations of 238U, 232Th, and 40K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of 238U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of 232Th and 40K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope 137Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems. Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.

Characteristics of Particulate Matter Generated during the Operation of a Small Directly Fired Coffee Roaster (소형 직화식 커피 로스터 이용 시 발생하는 미세먼지 특성 연구)

  • Yu, Da Eun;Kim, Seung Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.2
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    • pp.236-248
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    • 2020
  • Objectives: The purpose of this study was to evaluate the concentrations of particulate matter generated during coffee roasting and to study various factors affecting the concentrations. Methods: Differences in concentration levels were investigated based on various factors to understand the emission rates of particulate matter over time and to compare the mass and number concentrations according to their size. Sampling was performed in closed laboratories without the operation of air conditioning or ventilation. Optical Particle Sizer(OPS) was used as a measuring device. An OPS measures using a light-scattering method. Sampling was performed for sixty minutes at one-minute intervals. The background concentration was measured for about 30 minutes before starting of coffee roasting. The concentrations of particulate matter generated during coffee roasting were monitored until roasted coffee beans were removed from the roaster and cooled down. Several factors affecting the concentrations of particulate matter were investigated, which includes the origins of green beans, the roasting level, and the input amount of green beans. Results: The results of this study may be summarized as follows: 1) There was no difference in particulate matter concentration levels by the origin of the green beans, but a statistically significant difference in concentration levels by roasting level and the input amount of green beans; The higher the roasting level, the higher was the particulate matter concentration. The more green beans we put in the roaster, the higher were the concentrations; 2) The PM10 mass concentrations increased over time. The average concentration after roasting was higher than the average concentration during roasting; 3) In the distribution of mass and number concentration by particle diameter, the majority of particles was below 2.5 ㎛. Conclusions: Persons who work in roastery cafes can be exposed to high concentrations of particulate matter. Therefore, personal exposure and risk assessment should be conducted for roastery cafe workers.

The association of perfluoroalkyl substances (PFAS) exposure and kidney function in Korean adolescents using data from Korean National Environmental Health Survey (KoNEHS) cycle 4 (2018-2020): a cross-sectional study

  • Jisuk Yun;Eun-Chul Jang;Soon-Chan Kwon;Young-Sun Min;Yong-Jin Lee
    • Annals of Occupational and Environmental Medicine
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    • v.35
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    • pp.5.1-5.14
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    • 2023
  • Background: Perfluoroalkyl substances (PFAS) are chemicals widely used in various products in everyday life. Due to its unique strong binding force, the half-life of PFAS is very long, so bioaccumulation and toxicity to the human body are long-standing concerns. In particular, effects on kidney function have recently emerged and there are no studies on the effect of PFAS on kidney function through epidemiological investigations in Korea. From 2018 to 2020, the Korean National Environmental Health Survey (KoNEHS) cycle 4, conducted an epidemiological investigation on the blood concentration of PFAS for the first time in Korea. Based on this data, the relationship between PFAS blood concentration and kidney function was analyzed for adolescents. Methods: We investigated 5 types of PFAS and their total blood concentration in 811 middle and high school students, living in Korea and included in KoNEHS cycle 4, and tried to find changes in kidney function in relation to PFAS concentration. After dividing the concentration of each of the 5 PFAS and the total concentration into quartiles, multivariable linear regression was performed to assess the correlation with kidney function. The bedside Schwartz equation was used as an indicator of kidney function. Results: As a result of multivariable linear regression, when observing a change in kidney function according to the increase in the concentration of each of the 5 PFAS and their total, a significant decrease in kidney function was confirmed in some or all quartiles. Conclusions: In this cross-sectional study of Korean adolescents based on KoNEHS data, a negative correlation between serum PFAS concentration and kidney function was found. A well-designed longitudinal study and continuous follow-up are necessary.

A Study on Seasonal Nitrogen Treatment Characteristics according to Design of Constructed Wetland (인공습지의 형태에 따른 계절별 질소처리 특성 연구)

  • Son, Yeong-Kwon;Yoon, Chun-Gyeong;Kim, Jun-Sik;Kim, Hyung-Joong
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.94-101
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    • 2012
  • The performance data for eight years from a free-surface-flow constructed wetland system receiving agricultural tailwater were used to analyze denitrification rate and nitrogen treatment characteristics according to season and wetland design. Seasonal difference between growing season (March~November) and winter season (December~February) was shown in the concentration of all nitrogen species. Seasonal nitrogen treatment has similar trend with temperature and measured denitrification rate. The highest denitrification rate was measured in July, but treatment efficiency was most higher in May and June. Nitrogen absorption of vegetation could affect to these wetland performances, therefore dense population of wetland vegetation might be helpful. According to design of wetland, at least 25~50 m of wetland length was needed to decrease effluent T-N concentration to background concentration in growing season. In winter season, wetland needed much longer distance to reduce T-N concentration. Mass removal rate was continuously high through whole year because runoff coefficient was low in winter season. Applicability of constructed wetland was observed for the total maximum daily load that control T-N load.

A comparison of 0.075% and 0.15% of ropivacaine with fentanyl for postoperative patient controlled epidural analgesia after laparoscopic gynecologic surgery

  • Jung, Hyun Chul;Seo, Hyo Jung;Lee, Deok Hee;Park, Sang-Jin
    • Journal of Yeungnam Medical Science
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    • v.34 no.1
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    • pp.37-42
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    • 2017
  • Background: A motor blockade of lower limbs interferes with early ambulation and limits the usefulness of patient-controlled epidural analgesia (PCEA). The concentration of local anesthetic solution is a major determinant for motor block with PCEA. We compared the effects of epidural infusion of 0.075% ropivacaine with 0.15% epidural ropivacaine on postoperative analgesia, motor block of lower limbs, and other side effects. Methods: A total of 70 patients undergoing laparoscopic gynecologic surgery received epidural infusions (group R1, 0.15% ropivacaine with fentanyl; group R2, 0.075% ropivacaine with fentanyl). Pain score, motor block, and side effects (hypotension, nausea, vomiting, pruritus, urinary retention, dizziness, and numbness) were measured. Results: There were no significant differences in the demographic profiles between the groups. Pain scores of the group R1 and the group R2 were not significantly different. Motor block was more frequent in the group R1 (0.15% ropivacaine with fentanyl) than in the group R2 (0.075% ropivacaine with fentanyl). Conclusion: Lower concentration of ropivacaine (0.075%), when compared with higher concentration of ropivacaine (0.15%), seemed to provide similar analgesia with less motor blockade of the lower limbs for the purpose of PCEA.

A Study on The Gamification Elements of Eye-tracker for Improving Attention Concentration of Children with Quadratic Palsy with Intellectual Disability (지적장애를 동반한 사지마비형 뇌성마비 아동의 주의집중력 향상을 위한 아이트래커기반 게임화 요소 연구)

  • Jeong, Yoona;Woo, Tack
    • Journal of Korea Game Society
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    • v.20 no.4
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    • pp.57-66
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    • 2020
  • In this paper, we analyze the interaction features using eye-tracker and the characteristics of attention concentration of children with intellectual disabilities, and present gamification elements that can be used when designing digital contents for them. For children with quadriplegic cerebral palsy, eye-trackers will increase the accessibility of digital contents. Foreground gamification can be used for selective attention concentration, background gamification and intrinsic motivation to sustain attention concentration, and foreground gamification and extrinsic motivation for mobility.

Analysis of Variation in Total Airborne Bacteria Concentration to Assess the Performance of Biological Safety Cabinets in Microbial Laboratories

  • Hwang, Sung Ho;Park, Hyun Hee;Yoon, Chung Sik
    • Safety and Health at Work
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    • v.5 no.1
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    • pp.23-26
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    • 2014
  • Background: The purpose of this study was to compare the concentration of total airborne bacteria (TAB) in biosafety cabinets (BSCs) at universities and hospital microbial laboratories to assess the performance of BSCs. Methods: TAB was determined by using the single-stage Anderson sampler (BioStage Viable Cascade Impactor). The samples were obtained three times (with the BSC turned off and the shield open; with the BSC turned off and the shield closed; and with the BSC tuned on and operating) from the areas in front of 11 BSCs. Results: TAB concentrations of accredited and nonaccredited BSCs were determined. No significant differences were observed in the TAB concentrations of the accredited BSCs and the nonaccredited BSCs for the areas outside the BSCs in the laboratories (p > 0.05). TAB concentrations for the BSCs sampled with the shield open and the instrument turned off showed differences based on the sampling site outside the BSC in each laboratory. Conclusion: These results imply that TAB concentration is not altered by the performance of the BSCs or TAB itself and/or concentration of TAB outside the BSC is not a good index of BSC performance.

Experimental Study on the Soot Formation Characteristics of Alkane-based Single Fuel Droplet (알케인계 단일 연료 액적의 Soot 생성 특성에 관한 실험적 연구)

  • Lim, Young Chan;Suh, Hyun Kyu
    • Journal of ILASS-Korea
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    • v.22 no.2
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    • pp.80-86
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    • 2017
  • The soot formation characteristics of various alkane-based single fuel droplets were studied in this work. Also, This study was performed to provide the database of the soot behavior and formation of alkane-based single fuel droplet. The experimental conditions were set to 1.0 atm of ambient pressure ($P_{amb}$), 21% of oxygen concentration ($O_2$) and 79% of nitrogen concentration ($N_2$). Combustion and soot formation of single fuel droplet was visualized by visualization system with high speed camera. At the same time, ambient pressure, oxygen concentration and nitrogen concentration were maintained by ambient condition control system. Soot formation characteristics was analyzed and compared on the basis of intensity ratio ($I/I_0$) of background image. The results of toluene fuel droplet showed the largest soot generation. Soot volume fraction ($f_v$) was almost the same under the identical fuel types regardless of various initial droplet diameter ($d_0$) since thermophoretic flux was not much changed under the same ambient conditions.

Green Tobacco Sickness Among Tobacco Harvesters in a Korean Village

  • Park, Sung-Jun;Lim, Hyun-Sul;Lee, Kwan;Yoo, Seok-Ju
    • Safety and Health at Work
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    • v.9 no.1
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    • pp.71-74
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    • 2018
  • Background: Green tobacco sickness (GTS), an occupational disease in tobacco harvesters, is a form of acute nicotine intoxication by nicotine absorption through the skin from the wet green tobacco plant. We carried out a questionnaire survey and measured cotinine concentration, the metabolic product of nicotine, to determine the prevalence, incidence, and risk factors of GTS in Korean tobacco harvesters. Methods: We measured cotinine concentrations, and administered a questionnaire survey to tobacco harvesters in Cheongsong-gun, Gyeongsangbuk-do, Korea. We repeatedly measured urine cotinine concentration five times with a questionnaire survey. Results: Cotinine concentration at dawn was significantly higher than that at other times; it was significantly lower during the nonharvesting period than during the harvesting period. However, little change in cotinine concentration was detected in the daytime during the harvesting period. Study participants included 20 men and 20 women. The prevalence of GTS was 37.5% and was significantly higher in women than in men (55.0% vs. 20.0%, p < 0.01). GTS incidence according to number of workdays was 3.4 occurrences/100 person days. Conclusion: In this study, nicotine exposure and metabolism were experimentally determined from the time of cotinine exposure, and biological monitoring was performed in each season. In the future, this information may be valuable for medical decision-making in GTS prevention.

Review of outcomes of using lower ethanol concentration (83%) in percutaneous ultrasound-guided renal cyst sclerotherapy in dogs

  • Sanghyeon Yoon;Jungmin Kwak;Deokho Im;Hakyoung Yoon
    • Journal of Veterinary Science
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    • v.24 no.5
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    • pp.61.1-61.12
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    • 2023
  • Background: Percutaneous renal cyst sclerotherapy (PRCS) as a treatment for renal cysts is usually performed with a high concentration of ethanol (≥ 90%). This study reviewed cases in which a lower concentration of ethanol (83%) was used for the procedure in dogs. Methods: Records of cases of renal cysts treated by sclerotherapy using 83% ethanol in dogs were reviewed. Outcomes of the treatment were evaluated by comparing volumes of renal cysts before the procedure and the volumes after treatment, using ultrasound images with the volume reduction rates classified as follows: < 50% of initial volume (failed); ≥ 50% but < 80% of initial volume (partial success); ≥ 80% but < 95% of initial volume (great success); ≥ 95% of initial volume (complete success). Results: Out of nine dog kidneys, renal cysts sclerotherapy with 83% ethanol achieved partial success in one kidney, great success in four, and complete success in the other four. No side effect was observed. The mean of the volume-reduction rates was 90.00 ± 11.00 while the minimum and maximum reduction rates were 65% and 100%, respectively. Conclusions: The lower ethanol concentration (83%) is good for disinfecting kidneys in PRCS.