• Title/Summary/Keyword: Extreme heat stress

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Pilot research of thermal stress by extreme heat (폭염에 의해 인체가 받는 열적스트레스의 실험적 연구)

  • Park, Jong-Kil;Jung, Woo-Sik;Kim, Eun-Byul;Song, Jeong-Hui
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.653-655
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    • 2008
  • In order to examine the influences by the extreme weather changes on the human physical conditions, we need to undertake human biometeorology research such as the assesment on the extreme heat's influences on human health. Most of the preceding studied have been found to be focused on the influences by extreme heat on the human body, they used statistics on the daily mortality. But thismethod estimate an indirectly influences by extreme heat on the human body. So, to be able to predict the possible directly influences by the extreme heat on the physical conditions. We measure thermal stress by extreme heat.

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Study on the Establishment of Threshold Criteria for Heat Health Watch Warning System in Korea; Part I : Establishment of Criteria and Verification (고온건강경보시스템 기준 설정에 관한 연구( I ) - 기준 설정 및 검증 -)

  • Park, Jong-Kil;Jung, Woo-Sik;Kim, Eun-Byul
    • Journal of Environmental Science International
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    • v.18 no.7
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    • pp.767-780
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    • 2009
  • This study investigates the standard, duration period and excess mortality of extreme heat using the standardized daily mortality data from 1991 to 2004, establishing a standard threshold Criteria for Heat Health Watch Warning System in Korea. It ultimately aims to provide the guidance in building up Heat Health Watch Warning System for Korea by suggesting the standard to quantify thermal stress from heat. The standard threshold Criteria for Heat Health Watch Warning System for Seoul metropolitan city takes into account both daily maximum temperature and daily maximum heat index(HI) and consists of four phases; caution, extreme caution, danger, and extreme danger. Extreme caution phase and danger phase are used as the advisory and warning of extreme heat, respectively. Since the nationwide distribution of the frequency of extreme heat day and the excess mortality rate shows little difference across regions, the standard threshold Criteria for Heat Health Watch Warning System for Seoul metropolitan city can be used for other regions.

Effects of an Extreme Heat Adaptation Program in Hypertensive Patients (고혈압환자의 폭염 적응력 증진을 위한 프로그램 효과)

  • Jeong, Seong Hee;Kim, Nam Soon;Chae, Sumi;Lee, Eun Ju
    • Journal of Korean Biological Nursing Science
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    • v.16 no.3
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    • pp.164-172
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    • 2014
  • Purpose: The purpose of this study was to identify the effects of an extreme heat Adaptation Program on the blood pressure, stress response, self-efficacy, and knowledge of management of hypertension and extreme heat of patients who suffered from hypertension. Methods: A quasi-experimental study with a non-equivalent control group pretest-posttest design was used. The data collection period was between July 2 and August 20, 2012. Thirty-seven patients participated in the study (18 in the experimental group and 19 in the control group). Data were analyzed using $X^2$-test, t-test, and Cronbach's alpha coefficients with SPSS/WIN 19.0. Results: Patients who participated in the program showed statistically significant improvements in systolic blood pressure (SBP), self-efficacy, and knowledge of management of hypertension and extreme heat. Conclusion: The results indicate that this extreme heat adaptation program can be utilized for patients suffering from hypertension in order to reduce their SBP and to increase self-efficacy and knowledge of management of hypertension and extreme heat. Therefore, it is recommended that this program be used for elderly patients suffering from chronic disease.

The Burdens of Occupational Heat Exposure-related Symptoms and Contributing Factors Among Workers in Sugarcane Factories in Ethiopia: Heat Stress Wet Bulb Globe Temperature Meter

  • Mitiku B. Debela;Achenef M. Begosaw;Negussie Deyessa;Muluken Azage
    • Safety and Health at Work
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    • v.14 no.3
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    • pp.325-331
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    • 2023
  • Background: Heat stress is a harmful physical hazard in many occupational settings. However, consequences of occupational heat exposure among workers in a sugarcane factory in Ethiopia are not well characterized. This study aimed to assess the level of occupational heat exposure-related symptoms and contributing factors. Methods: In this cross-sectional study, five workstations were selected for temperature measurement. Heat stress levels were measured using a wet-bulb globe temperature index meter. A stratified random sampling technique was used to select 1,524 participants. Heat-related symptoms were assessed using validated questionnaires. Results: The level of occupational heat exposure was 72.4% (95% CI: 70.2%-74.8%), while 71.6% (95% CI: 69.3%-74.9%) of participants experienced at least one symptom related to heat stress. The most common heat-related symptoms were swelling of hands and feet (78%), severe thirst (77.8%) and dry mouth (77.4%). The identified risk factors were a lack of reflective shields (AOR: 2.20, 95% CI: 1.53, 3.17), not-enclosed extreme heat sources (AOR: 1.76, 95% CI: 1.23, 2.51), a lack of access to shade (AOR: 9.62, 95% CI: 6.20, 14.92), and inappropriate protective clothing provision (AOR: 1.58, 95% CI: 1.27, 2.71). Conclusions: The burden of occupational heat exposure and heat-induced symptoms was high. Lack of reflective shields, the absence of enclosed extreme heat sources, a lack of access to shade, and inappropriate protective clothing provision were considerable attributes of heat stress. Therefore, the use of mechanical solutions to stop heat emissions at their sources and the key factors identified were areas for future intervention.

Effects of extreme heat stress and continuous lighting on growth performance and blood lipid in broiler chickens (연속조명과 폭염 스트레스가 육계의 혈액지질 및 성장능력에 미치는 영향)

  • Park, Sang-Oh;Hwangbo, Jong;Ryu, Chae-Min;Yoon, Jae-Sung;Park, Byung-Sung;Kang, Hwan-Ku;Seo, Ok-Suk;Chae, Hyun-Seok;Choi, Hee-Chul;Choi, Yang-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.78-87
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    • 2013
  • In this study, the effect of extreme heat diet on growth performance, lymphoid organ, blood immunoglobulin and cecum microflora change in broilers exposed to continuous lighting and extreme heat stress (EHS) was studied. Broilers raised under normal environment temperature ($25^{\circ}C$ or extreme heat stress temperature ($33{\pm}2^{\circ}C$, and consumed chow diet (CD) or extreme heat stress diet (EHSD). Five hundred Ross 308 day-old commercial broilers were arranged in a completely randomized block design of 5 treatment groups with 4 repetitions (25 heads per repetition pen). The broilers were divided into: T1 (normal environment+CD), T2 (EHS+CD), T3 (EHS+EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses), T4 (EHS+EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses, and 1.5 times more methionine and lysine than CD), and T5 (EHS+EHSD in which the tallow in CD was substituted by soy oil, contained 5% molasses, 1.5 times more methionine and lysine than CD, and 300ppm of vitamin C). The EHS significantly reduced the body weight gain and feed intake. The blood immunoglobulin, bursa of Fabricius, thymus, and spleen weight were significantly reduced when broilers were exposed to EHS. Compared to the normal environment temperature group, the cecum Lactobacillus sp. was low in the EHS treatment group, while Escherichia sp., Salmonella sp. and total aerobic bacteria in the EHS treatment group were high. A statistically significant difference was acknowledged between the treatment groups.

Effects of Inverse Lighting and Diet with Soy Oil on Growth Performance and Short Chain Fatty Acid of Broiler Exposed to Extreme Heat Stress (대두유 사료와 역전점등이 폭염 육계의 짧은 사슬지방산 및 성장능력에 미치는 영향)

  • Yoon, Jae-Sung;Kang, Hwan-Ku;Ryu, Chae-Min;Park, Sang-Oh;Park, Byung-Sung;Hwangbo, Jong;Seo, Ok-Suk;Chae, Hyun-Seok;Choi, Hee-Chul;Choi, Yang-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.127-138
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    • 2013
  • This study investigated the effects of feeding the broilers that are exposed to extreme heat stress (EHS, $33{\pm}2^{\circ}C$) with extreme heat stress diet (EHSD) containing adequate amount of soy oil and other nutrients on their growth performance. 500 broiler chickens (Ross 308) were randomized into five dietary treatment groups according to a randomized block design on the day they were hatched. Each group was further divided into four repeat pens with each repeat pen comprising 25 chickens. The five dietary treatment groups were: T1 (Normal ambient condition + basal diet (BD), T2 (EHS +BCD), T3 (EHS + extreme heat stress diet (EHSD) prepared from BD with tallow replaced with soy oil and containing molasses 2%), T4 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2% and methionine and lysine of 1.5 times greater quantities than in BD), and T5 (EHS + EHSD prepared from BD with tallow replaced with soy oil and containing molasses 2%, methionine and lysine of 1.5 times greater quantities than in BD, and vitamin C 200 ppm) with inverse lighting. The body weight gain of the broilers increased significantly in T4 and T5 as compared with that in T1 and T2. Weights of the lymphoid organ, bursa of Fabricius, thymus, and spleen were similar between all groups. Serum concentrations of IgG, IgG and IgM were higher in T4 and T5 than inT1 and T2, but the corticosterone concentration decreased significantly in them. In T4 and T5, Lactobacillus in the cecum increased, but Escherichia, coliform, and total aerobic bacteria decreased rather significantly, compared with those in T1 and T2. Contents of acetic acid, propionic acid and total SCFA were significantly higher in T4 and T5 than in T1 and T2.

Effects of inverse lighting and extreme heat diet on short chain fatty acid and blood lipid profile in extreme heat stress-exposed broilers (폭염 브로일러 닭의 혈액지질 및 짧은 사슬지방산에 대한 폭염사료와 역전점등 효과)

  • Park, Sang-Oh;Hwangbo, Jong;Park, Byung-Sung;Choi, Hee-Chul
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.400-410
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    • 2013
  • This study was carried out to investigate the effects of feeding the broilers that are exposed to extreme heat stress by control of inverse lighting times with night restricted feeding of extreme heat diet(EHD1, 2: extreme heat diet) containing different amount of soy oil, molasses, amino acids and vitamin C on short chain fatty acid and blood lipid profile. 300 broiler chickens(Abaica strain) were randomized into four dietary treatment groups according to a randomized block design on the day they were hatched. The four dietary treatment groups were: T1(EHD 1, 10:00~19:00 Dark, 19:00~10:00 Light), T2(EHD 2, 10:00~19:00 Dark, 19:00~10:00 Light), T3(EHD 1, 09:00~18:00 Dark, 18:00~09:00 Light), T4(EHD 2, 09:00~18:00 Dark, 18:00~09:00 Light). The body weight gain of the broilers was highest in T2, and high in order T1, T4, T3(p<0.05). Weights of the lymphoid organ, thymus and bursa of Fabricius were high in T1, T2 as compared to T3, T4 but spleen was lower in T4 than T1, T2, T3(p<0.05). Blood triglyceride, total cholesterol and glucose were higher in T1, T2 than T3, T4(p<0.05). LDL-C was high in orderT4, T3, T2, T1 but HDL-C showed the opposite trend(p<0.05). Blood concentrations of IgG, IgG and IgM were higher in T1, T2 than inT3, T4, but the corticosterone concentration decreased significantly in them. In T1 and T2, Lactobacillus in the feces increased, but total aerobic bacteria, E.coli, coliform bacteria was decreased rather significantly, compared with those in T3 and T4(p<0.05). Concentrations of acetic acid, propionic acid and total SCFA in cecum were high in order T2, T1, T3, T4, but butyric acid, isobutyric acid, valeric acid, isovaleric acid were lower in T1, T2 than in T3, T4 (p<0.05).

Effect of Heat Stress of Extreme Heat Lever on Muscle functionand Muscle Injury Markers in Elderly Women (열 스트레스가 여성노인들의 근기능 및 근손상에 미치는 영향)

  • Park, Sok;Lee, Chone Ho;Back, Seung Ok;Shin, Yong Up;Kim, Jung Suk;Cho, Young Wung;Lee, Young Jun
    • 한국노년학
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    • v.30 no.3
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    • pp.793-802
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    • 2010
  • The purpose of this study was to examine the influence of extreme heat on muscle function and muscle injury marker in elderly women. The subjects of this study were eight post-menopausal elderly women without any metabolic disease. All eight subjects were asked to perform the knee joint isokinetic exercise using isokinetic equipment (cybex) in the laboratory and experimental temperature within laboratory was adjusted to two conditions: extreme heat temperature(33±0.5℃) and normal temperature(20±0.5℃) maintained in 50±3% humidity conditions. Each experimental exercise was monitored and analyzed the change of HSP70, LDH and CK. Muscular functions (peak torque, total work, percentage of peak torque body weight, fatigue index, average power and total work) were significant differences at exercise between temperatural conditions (p<.05). In extreme heat temperature, muscular injury markers (HSP70, LDH and CK) were increased, threfore resulted in significantly higher than normal temperature(p<.05). These results show that extreme heat temperature can decrease muscle function in elderly women.

Thermal-hydraulic Analysis of Operator Action Time on Coping Strategy of LUHS Event for OPR1000 (OPR1000형 원전의 최종열제거원 상실사고 대처전략 및 운전원 조치 시간에 따른 열수력 거동 분석)

  • Song, Jun Kyu
    • Journal of the Korean Society of Safety
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    • v.35 no.5
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    • pp.121-127
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    • 2020
  • Since the Fukushima nuclear accident in 2011, the public were concerned about the safety of Nuclear Power Plants (NPPs) in extreme natural disaster situations, such as earthquakes, flooding, heavy rain and tsunami, have been increasing around the world. Accordingly, the Stress Test was conducted in Europe, Japan, Russia, and other countries by reassessing the safety and response capabilities of NPPs in extreme natural disaster situations that exceed the design basis. The extreme natural disaster can put the NPPs in beyond-design-basis conditions such as the loss of the power system and the ultimate heat sink. The behaviors and capabilities of NPPs with losing their essential safety functions should be measured to find and supplement weak areas in hardware, procedures and coping strategies. The Loss of Ultimate Heat Sink (LUHS) accident assumes impairment of the essential service water system accompanying the failure of the component cooling water system. In such conditions, residual heat removal and cooling of safety-relevant components are not possible for a long period of time. It is therefore very important to establish coping strategies considering all available equipment to mitigate the consequence of the LUHS accident and keep the NPPs safe. In this study, thermal hydraulic behavior of the LUHS event was analyzed using RELAP5/Mod3.3 code. We also performed the sensitivity analysis to identify the effects of the operator recovery actions and operation strategy for charging pumps on the results of the LUHS accident.

Rescue of Oxidative Stress by Molecular Chaperones in Yeast

  • Ueom Jeonghoon;Kang Sooim;Lee Kyunghee
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2002.10a
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    • pp.76-78
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    • 2002
  • Heat shock proteins (HSPs) are induced in most living cells by mild heat treatment, ethanol, heavy metal ions and hypoxia. In yeast Saccharomyces cerevisiae, mild heat pretreatment strongly induces Hsp104 and thus provide acquired thermotolerance. The ability of hsp104 deleted mutant $({\triangle}hsp104)$ to acquire tolerance to extreme temperature is severely impaired. In providing thermotolerance, two ATP binding domains are indispensible, as demonstrated in ClpA and ClpB proteases of E. coli. The mechanisms by which Hsp104 protects cells from severe heat stress are not yet completely elucidated. We have investigated regulation of mitochondrial metabolic pathways controlled by the functional Hsp104 protein using $^{13}C_NMR$ spectroscopy and observed that the turnover rate of TCA cycle was enhanced in the absence of Hsp104. Production of ROS, which are toxic to kill cells radiply via oxidative stress, was also examined by fluorescence assay. Mitochondrial dysfunction was manifested in increased ROS levels and higher sensitivity for oxidative stress in the absence of Hsp104 protein expressed. Finally, we have identified mitochondrial complex I and Ferritin as binding protein(s) of Hsp104 by yeast two hybrid experiment. Based on these observations, we suggest that Hsp104 protein functions as a protector of oxidative stress via either keeping mitochondrial integrity, direct binding to mitochonrial components or regulating metal-catalyzed redox chemistry.

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