• 제목/요약/키워드: Causal association

검색결과 978건 처리시간 0.026초

Firefighting and Cancer: A Meta-analysis of Cohort Studies in the Context of Cancer Hazard Identification

  • Nathan L. DeBono;Robert D. Daniels ;Laura E. Beane Freeman ;Judith M. Graber ;Johnni Hansen ;Lauren R. Teras ;Tim Driscoll ;Kristina Kjaerheim;Paul A. Demers ;Deborah C. Glass;David Kriebel;Tracy L. Kirkham;Roland Wedekind;Adalberto M. Filho;Leslie Stayner ;Mary K. Schubauer-Berigan
    • Safety and Health at Work
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    • 제14권2호
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    • pp.141-152
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    • 2023
  • Objective: We performed a meta-analysis of epidemiological results for the association between occupational exposure as a firefighter and cancer as part of the broader evidence synthesis work of the IARC Monographs program. Methods: A systematic literature search was conducted to identify cohort studies of firefighters followed for cancer incidence and mortality. Studies were evaluated for the influence of key biases on results. Random-effects meta-analysis models were used to estimate the association between ever-employment and duration of employment as a firefighter and risk of 12 selected cancers. The impact of bias was explored in sensitivity analyses. Results: Among the 16 included cancer incidence studies, the estimated meta-rate ratio, 95% confidence interval (CI), and heterogeneity statistic (I2) for ever-employment as a career firefighter compared mostly to general populations were 1.58 (1.14-2.20, 8%) for mesothelioma, 1.16 (1.08-1.26, 0%) for bladder cancer, 1.21 (1.12-1.32, 81%) for prostate cancer, 1.37 (1.03-1.82, 56%) for testicular cancer, 1.19 (1.07-1.32, 37%) for colon cancer, 1.36 (1.15-1.62, 83%) for melanoma, 1.12 (1.01-1.25, 0%) for non-Hodgkin lymphoma, 1.28 (1.02-1.61, 40%) for thyroid cancer, and 1.09 (0.92-1.29, 55%) for kidney cancer. Ever-employment as a firefighter was not positively associated with lung, nervous system, or stomach cancer. Results for mesothelioma and bladder cancer exhibited low heterogeneity and were largely robust across sensitivity analyses. Conclusions: There is epidemiological evidence to support a causal relationship between occupational exposure as a firefighter and certain cancers. Challenges persist in the body of evidence related to the quality of exposure assessment, confounding, and medical surveillance bias.

지구과학 논문과 지구과학 교과서 텍스트의 과학 언어적 특성 비교 (Comparison of the Features of Science Language between Texts of Earth Science Articles and Earth Science Textbooks)

  • 이정아;김찬종;맹승호
    • 한국과학교육학회지
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    • 제27권5호
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    • pp.367-378
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    • 2007
  • 과학 교과서와 과학 연구 논문의 과학 언어적 특성을 조사하기 위하여 지구과학 교과서 2 종과 지구과학 논문 2 편을 선정하여 각 텍스트의 과학 용어 분류, 설명 텍스트의 구조 분석과 접속 관계를 통한 추론 분석, 접속어의 기능에 대한 분석 방법을 적용하여 분석하였다. 연구 결과, 지구과학 교과서에서 드러난 학교 과학의 언어는 명명어의 비중이 높으며, 정의/예시 구조와 기술 구조 중심의 설명 텍스트 구조를 보였다. 또한, 논리적 추론보다는 부가적인 나열 관계를 나타내는 내적 관계가 우세하였다. 이에 반해 지구과학 논문에서 볼 수 있는 과학자의 과학 언어는 명명어의 비중이 큰 가운데서도 과정어와 개념어의 비중이 과학 교과서의 과학 언어에 비해 높았으며, '도입 - 연관 계열 - 결론'에 이르는 설명 텍스트의 도식적 구조를 갖추고 있었다. 또한, 연관 계열을 이루는 각 문장의 텍스트 구조는 원인/결과 구조 또는 기술 구조에 뒤이은 문제/해결 구조를 보였으며, 각 문장틀 간에 부사형 어미나 동사를 이용한 내적 관계를 통해 인과적 추론 또는 귀추적 추론 관계를 표현하고 있었다. 학생들의 진정한 과학 언어 사용을 위해서는 두 언어 사이의 간극을 줄이는 것이 필요하다. 이를 위해 학교 과학의 언어와 과학자의 언어를 매개하는 지구과학 교사의 교수 언어로서 중간 언어를 제안하였다.

인천시 고잔동에서 제기된 유리섬유에 의한 건강피해 역학 조사 (Health Assessment for Glass Fibre Landfill at Gozan-dong, Inchon)

  • 조수헌;주영수;김경렬;이강근;홍국선;은희철;송동빈;홍재웅;권호장;하미나;한상환;성주헌;강종원
    • Journal of Preventive Medicine and Public Health
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    • 제30권1호
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    • pp.77-101
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    • 1997
  • In September 1994, residents of Gozan-dong, Incheon City, made a petition to the government about their health problems which might be caused by previous glass fibre landfill nearby 'H' company. In february 1995, at regular academic meeting of occupational and environmental medicine, a research team of 'D' University presented that they had found glass fibres in groundwater of the area through their survey. They were suspicious of probable association between ingestion of groundwater contaminated with glass fibres and skin tumors among residents. A joint research team was formed and carried out the survey of environment concerning groundwater and its glass fibre existence, and health assessment of residents in the area and industrial workers of 'H' company during May to November, 1995. Analysis of groundwater flow system indicates that the flow lines from the glass fibre landfill pass through or terminate at the 6 houses around the landfill. This means that the groundwater of the 6 houses around the glass fibre landfill could be affected by some possible contaminants from the landfill, but the groundwater quality of the other houses was irrelevant to the landfill. The qualitative and qualitative analyses for glass fibres in 54 groundwater samples including those from the nearby 6 houses, were carried out using SEM equipped with EDS, resulting in no evidence for the presence of glass fibres in the waters. Major precipitates, formed in waters while boiling, were identified as calcium carbonates, in particulary, aragonites in needle form. The results of health assessments of 889 residents in Gozan-dong, participated in this study, showed statistically significant differences in past medical histories of skin tumor and respiratory disease between the exposed group (31 persons who inhabited in 6 houses around the landfill) and the control group, but no significant differences in past medical histories of other diseases, such as cancer mortality, current gastroscopic findings, current skin diseases and respiratory diseases, etc. Also, we could not prove any glass fibres in excised specimens of 9 skin tumors in both groups and there were no health problems possibly associated with glass fibres in employees of the 'H' company. After all, we could not authenticate the association, raised by prior investigators, between groundwater streams, assumedly contaminated with glass fibres or not, and specific disease morbidities or common disease/symptom prevalences. That is, we could not find any glass fibres in groundwater as the only exposure factor of this study hypothesis, and there were not enough certain evidences such as increasing disease prevalences, for examples, skin, respiratory and gastrointestinal diseases etc, possibly related to glass fibre exposure, in exposed group. As a matter of course, the conditions for confirming causal association, for example, strength of the association, consistency of the association, specificity of the association, temporality of the association and dose-response relationship etc, have not been satisfied. In conclusion, we were not able to certify the hypothesis that contamination of groundwater with glass fibres might cause any hazardous health effects in residents who used it for drinking.

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과소/과잉노동과 근로환경 (Under and Over Employment and Working Conditions)

  • 이경용;송세욱;김영선
    • 한국산업보건학회지
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    • 제24권4호
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    • pp.536-546
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    • 2014
  • Objectives: The major objective of this paper is compare the exposure work hours and experieence of ill health symptoms among under and over employment and matched group. Workers with over employment have more exposed to hazards than that with under employment because that workers with over employment work more than those with ender employment. Methods: This study as heuristics one used the third Korean Working Conditions Survey done by Occupational Safety and Health Research Institute in 2011. The sample size is 50,023 economic active persons. Over and under employment were measured by matching method of preferred and actual work hours. The exposed work hours to hazards were measured according to 13 hazardous factors and the experience of ill health symptoms were scaled by the number of experienced 14 ill health symptoms. To compare the exposure and the symptoms experience were compared by mean difference test with F test. Results: The proportion of over employment in male employees is 32.1% and that in female employees is 29.3% and under employment rate is 11.2% in mae and 13.9% in female employees. There is significant difference of the rate of over and under emplyment among age groups, industrial sectors, occupational groups and the state of employment. The difference of the exposed work hours to hazards among under, over and matched group were statistically significant in all hazards by gender. The exposed work hours to hazards in over employment were more than those in under employment. The number of experienced symptoms in over employment is statistically significantly more than that in under employment. Conclusions: Workers with over employment may be vulnerable group in the criteria of hazard exposure and health status. The results have some implications and limitations because that this study is heuristic one. The mismatch of preferred and actual working hours may be unfavorable work condition that has impact on safety and health of workers. The impact mechanism may be investigated as future study, Because that this study used cross sectional survey data, some causal relationships cannot be evaluated.

A Study on Technology Acceptance of Elderly living Alone in Smart City Environment: Based on AI Speaker

  • YOO, Hyun-Sil;SUH, Eung-Kyo;KIM, Tae-Hyung
    • 산경연구논집
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    • 제11권2호
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    • pp.41-48
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    • 2020
  • Purpose: This study is to examine the intention of the elderly who live alone in the customized AI speaker for the elderly living alone to improve the quality of life service for the elderly living alone in the smart city environment. Based on the quality of life model of the elderly, this study is applied to the technology acceptance model to investigate the relationship between perceived usefulness and ease of use on the sustained use intention. Research design, data and methodology: Residents in Suwon, Gyeonggi-do, selected as candidate local governments for the Smart City Challenge Project of the Ministry of Land, Infrastructure and Transport in June 2019 to measure the perceived technology acceptance of potential users for the AI technology for the elderly living alone as part of the smart city technology. In order to evaluate the intention of using AI speaker, which is the target system of this study, a video of a chatbot using experience of elderly people living alone was produced. Results: First of all, in order for the elderly living alone to have an attitude to use AI-based speakers, there should be a perceived usefulness of the quality of life of the elderly. However, ease of use did not show any significant causal relationship to attitude toward use. In addition, the attitude toward use weakly influenced the intention to use. In other words, elderly people living alone were not likely to have a significant effect on their attitude toward use. However, feeling that AI speakers are easy to use will help to improve the quality of life, which in turn led to the attitude toward using AI speakers, which could lead to indirect effects. Finally, the perceived usefulness of quality of life was found to have a weak effect on direct use intentions. Conclusions: This study conducted a study on the technology acceptance of service environment to improve the quality of life for the specific user group who live alone in the smart seat environment. In this study, we examined the effects of AI speaker on the elderly living alone to improve the quality of life for the elderly living alone.

소매유통업의 효율성 분석에 관한 연구 (An analysis of retail business efficiency in Korea)

  • 김순홍;유병국
    • 유통과학연구
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    • 제12권4호
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    • pp.23-30
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    • 2014
  • Purpose - The purpose of this study is to analyze the efficiency of retail businesses by dividing domestic retailers into discount stores, super supermarkets (SSMs), and department stores. It suggests retail-business investment strategies by using data environment analysis (DEA) to analyze how input elements such as store area, parking lot area, number of employees, and sales management expenses for the convenience of customers positively affect business performance measurements such as sales and visiting customers per day. Research Design, Data, and Methodology - The DEA model calculates a ratio of the weighted mean of various inputs to the weighted mean of various outputs and measures the efficiency of a specific decision making unit (DMU). The study included 19 companies (five discount store DMUs, ten SSM DMUs, and four department store DMUs). Because the business elements and sizes of retail store DMUs used in this analysis are different, average per-store input and output variables were used. Data were collected from "The Yearbook of Retail Industry in Korea (2012)." DEA analysis was used to determine differences in efficiency among discount stores, SSMs, and department stores in terms of the business elements of each retail business. It was also used to determine what business elements were excessively invested in by comparing and analyzing efficiency by business elements using SPSS software's ANOVA (Analysis of Variance). Results - The CCR and BCC efficiency analysis found that the efficiency of discount stores is low. We believe that the saturation state of discount stores is a major factor. The ANOVA analysis confirms the VRS hypothesis with a statistically significant difference among the three groups, based on an analysis confidence interval of 95%. CRS and SE were not found to be significantly different among the three groups. As for the post hoc test, which concretely shows differences by group, the Scheffe's multiple comparison analysis test found the average differences between group 1 (discount stores) and group 2 (SSM) to be statistically significant. Conclusions - The DEA efficiency analysis implies that investment in input elements, including store area, parking lot area, and sales management expenses, were excessive in the case of discount stores, while SSMs need to invest more in promotion activities such as gifts, events, and coupons for customer management. Department stores have found that small companies invest excessively in input elements. Department stores need to invest in differentiated shopping mall complexes. This study was limited in acquiring statistical data; various input variables which might have shown more secure customer management and promotional expenses could not be applied. As the study was limited in various aspects of the efficiency analyses because financial analyses of the companies and of causal relationships, including satisfaction and loyalty of visiting customers, were not done, these aspects will be examined in the next study.

일부지역 종합병원 행정직원의 조직공정성, 자아존중감 및 자기효능감이 직무스트레스에 미치는 융복합적 영향 분석 (Analysis of Convergent Influence of Organizational Justice, Self Esteem and Self Efficacy on Occupational Stress among Some Regional General Hospital Administrative Staff)

  • 배상윤;김승희
    • 디지털융복합연구
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    • 제16권5호
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    • pp.309-315
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    • 2018
  • 본 조사는 일부지역 종합병원 행정직원들의 조직공정성, 자아존중감 및 자기효능감과 직무스트레스 간의 관련성을 파악하고 직무스트레스에 미치는 융복합적 영향을 분석하였다. 자료수집은 2016년 11월 1일부터 2017년 1월 31일까지 구조화된 무기명 자기기입식 설문지를 통하여 시행되었으며, 조사대상은 임의로 선정된 J시의 11개 종합병원 행정직원 221명으로 하였다. 직무스트레스는 조직공정성의 절차공정성과 분배공정성, 자아존중감 및 자기효능감과는 음의 상관관계를 보였다. 공분산구조분석 결과, 종합병원 행정직원들의 조직공정성, 자아존중감, 자기효능감 및 직무스트레스의 인과관계를 확인하였으며, 조직공정성의 절차공정성 및 분배공정성이 높아질수록, 자아존중감이 높아질수록, 자기효능감이 높아질수록, 직무스트레스를 감소시키는 효과가 있는 것으로 나타났다. 이러한 결과를 볼 때, 종합병원 행정직원의 직무스트레스와 관련된 조직공정성, 자아존중감 및 자기효능감을 관리하는 노력이 필요하다. 분석결과는 종합병원 행정직원의 직무스트레스를 낮추는 조직 및 인사관리에 활용될 수 있다. 추후연구에서는 종합병원 행정직원의 직무스트레스에 영향을 미치는 융복합적인 추가요인에 대한 조사가 필요하다.

Chloromethylisothiazolinone (CMIT)과 Methylisothiazolinone (MIT)의 건강영향에 대한 고찰 - 가습기 살균제 폐 손상을 중심으로 - (Review of Health Effects Caused by Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) - Focusing on Humidifier Disinfectant-associated Lung Injury (HDLI) -)

  • 박동욱;김지원;류승훈;박지훈;권정환;이소연;박소영
    • 한국환경보건학회지
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    • 제46권3호
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    • pp.312-323
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    • 2020
  • Objective: This study aimed to summarize the physiochemical properties, toxicity, and legal regulation of chloromethylisothiazolinone (CMIT) and/or methylisothiazolinone (MIT), review the health effects caused by exposure to CMIT/MIT, and evaluate the individual association of lung injury with the use of humidifier disinfectants (HD) containing a mixture of CMIT and MIT. Method: A literature review was conducted by searching keywords such as CMIT, MIT, health effect, dermatitis, asthma, and lung injury, either singly or combined. Results: Both CMIT and/or MIT were found to be associated with the development of several types of adverse health effects. In particular, respiratory diseases including asthma, nasal symptoms, cough, and rhinitis were caused by the use of products including CMIT or/and MIT. The mixture of CMIT/MIT has been banned in cosmetics. As of the end of 2017, nine patients who were confirmed to have HD associated lung injury (HDLI) were found to have used only an HD brand containing CMIT and MIT. Their responses regarding the name of the HD used could be trustworthy based on the short duration of HD use (less than six months) before the onset of HDLI and frequent use of HD per day. Conclusion: According to the toxicity and HDLI cases, the use of HD containing CMIT and /or MIT can cause fatal lung injury. Further study with manufacturers' assistance is necessary in order to obtain more clear evidence on the causal relationship since HDLI cases are being reported continuously.

헤어살롱 서비스스케이프 차별화 성공사례 ("Servicescape" Differentiation in a Hair Salon)

  • 이상현;박철주
    • 유통과학연구
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    • 제13권9호
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    • pp.71-79
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    • 2015
  • Purpose - The purpose of this paper is to find out the effect of changes in the differentiated "servicescape" on the business performance in the hair salon industry using a case study. For this, we selected hair salon M located in Suwon. The shop is innovatively different from existing shops in terms of spatial layout and functionality. We conducted in-depth research, beginning with the launch of the shop concept through investment and ongoing stable sales. Research design, data, and methodology - The M hair salon is a start up shop providing a differentiated servicescape (physical environment where the service takes place) located in Suwon, Yeongtong-gu. We conducted research to investigate how spatial layout and functionality of the servicescape impact customers' perceived quality. The interview period and case analysis was May 2014 through March 2015, covering 11 months. To conduct the case analysis, we analyzed the spatial layout and functionality of existing shops and interviewed customers and experts about the difference between hair salon M and existing shops. Results - Our results found clues to the positive effect of spatial layout and functionality among servicescape factors on perceived service quality at the salon. The shop showed a fast payback of the principal investment, growth potential in contrast to competitors near the salon, and 45 percent returning customers. The problem with the spatial layout at existing shops was that customers were aware of the way other people were looking at them, since viewing angles overlapped, therefore there was a limitation to the relationship intensity with an exclusive hair designer. In contrast, the layout of the stands at the M salon kept the number of dressing stands limited to maximize the customer's emotional response. Additionally, because of the new layout of dressing stands hiding other customer voices and appearance in the salon, customers perceived their service space as independent. Therefore, they did not have to focus on their personal emotional response, which was one of the advantages of the new layout. Conclusions - This study conducted case study analysis by offering a new perspective focusing on spatial layout, previously not considered as an independent variable of quality evaluations and customer satisfaction in existing literature on hair salon management. Therefore, this study contributes to the field by offering an opportunity to discover the causal relationships between the overlooked physical environment and a customer's perceived quality. However, a process objectifying the results of the study through empirical analysis and hypotheses is needed to overcome the limitations of the case study approach and generalize the results. Moreover, it would be beneficial to conduct further empirical study of the relationship between the spatial layout provided in the case and a customer's emotional response and change in mood. In addition, an analysis is needed regarding how customers feel about the factors using the Kano Model. These suggestions would be considered in further study.

초등학교 여학생의 초경시기와 관련된 결정요인 분석 (Determinants of age at menarche in Korean elementary school girls)

  • 권미경;서은민;박경
    • Journal of Nutrition and Health
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    • 제48권4호
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    • pp.344-351
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    • 2015
  • 본 연구는 초경시기의 결정요인을 규명하기 위하여 대구 3개 지역 초등학교 5, 6학년 여학생 190명을 대상으로 개별 짝짓기 환자-대조군 연구를 실시하였고, 본 연구 결과를 요약하면 다음과 같다. 첫째, 비초경군에 비하여 초경군의 평균 수면시간이 더 적었다. 둘째, 어머니의 초경 나이가 빠를 수록 같은 또래에 비해 더 이른 초경 경험을 할 확률이 높았다. 셋째, 초경시기와 관련된 요인 중 비만이 가장 강한 연관성을 보였다. 전 세계적으로 초경 나이가 낮아지는 경향을 보이고 있으며, 우리나라 여성의 초경 나이도 현저하게 낮아지는 상황에서 본 연구의 결과는 중요한 기초자료로 활용될 것이다.