• 한국환경과학회지
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• 제19권1호
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• pp.1-8
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• 2010

Only limited information is available on the measured exposure levels of residents according to the construction age of apartments. As such, present study was conducted to measure and to compare the bedroom, living-room, and outdoor air levels of MTBE and benzene, toluene, ethyl benzene and m,p-xylene(BTEX) in both newer and older apartments. For both newer and older apartments, all the compounds except for MTBE showed significantly higher levels in bedrooms or living-rooms as compared to the outdoor concentrations. The ratio of bedroom or living-room median concentration to outdoor concentration was close to 1 for MTBE, whereas it was larger than 1 for other target compounds. It was also found that the bedroom and living-room appeared to have similar indoor sources and sinks for BTEX, but not for MTBE. The median concentration ratios of the newer apartments to the older apartments ranged from 1.63 to 1.81, depending upon the compounds. In contrast, the MTBE concentrations did not differ significantly between the newer and older apartments, thereby suggesting that although newer buildings could emit more VOCs, this is not applicable to all VOCs. Conclusively, the findings of present study should be considered, when designing exposure studies associated with VOC emissions in buildings and/or managing indoor air quality according to construction age of buildings.

• 한국치위생학회지
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• 제10권4호
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• pp.717-725
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• 2010

Objectives : This study was to determine the level of occupational exposure and quality of life and to investigate the effect of variables related occupational exposure on quality of life in dental hygienists. Methods : A survey questionnaire was mailed to dental hygienists from April 4 to May 15, 2010. The subjects were 256(56.9%), who were worked in dental hospital and clinic with mean age of $29.59{\pm}7.30$. Quality of life was measured using the WHOQOL-BREF. It consists of 26 items, each with 5-point likert scale. Self control of occupational exposure was measured using the 3-items. The data were analyzed with chi-square, t-test, one-way ANOVA, pearson correlation coefficients and multiple regression using the SPSS WIN 17.0 program. Results : Regarding quality of life, the subjects was a mean of 90.73 out of a maximum 130 points. The level of self control occupational exposure a mean of 3.20 out of a maximum 5 points. Self control of occupational exposure, frequency of panorama radiography, work experience of radiography had a significant impact on quality of life in dental hygienists. Conclusions : Based on the findings, occupational exposure is negatively associated with quality of life in dental hygienists. These results suggest that health promotion program should be considered various factors related occupational exposure in dental hygienists.

• Journal of Preventive Medicine and Public Health
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• 제28권2호
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• pp.386-397
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• 1995

A cross sectional study was performed to evaluate the neurobehavioral effects of chronic exposure of complex organic solvents, using NCTB(Neurobehavioral Core Test Battery) recommended by WHO(World Health Organization). Forty female shoe factory workers and twenty-two controls matched with age were participated. The tests were performed in the morning before start of work, to exclude the effects of acute exposure. Workers were exposed mainly to toluene, methyl ethyl ketone, n-hexane, cyclo-hexane, dichloroethylene, trichloroethylene, benzene, xylenes etc. The ranges of present solvent exposure of hygienic effect were $0.46\sim0.71$ in the process using adhesives indirectly, and $1.83\sim2.39$ in the process using it directly. We reclassified the subjects, according to cumulative exposure. It showed significantly poorer performances in high exposed group on Santa Ana Dexterity and Benton Visual Retention, compared with control group. After controlling confounder, the significances were still remained. But, further cohort studies, having the information of personal exposure dose from entering a factory, are required to clarify the effects of chronic exposure of complex organic solvents in relation to dose and duration of exposure.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7407-7411
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• 2014

The incidence of urban female breast cancer has been continuously increasing over the past decade with unknown etiology. One hypothesis for this increase is carcinogen exposure from tobacco. Therefore, the objective of this study was to investigate the risk of urban female breast cancer from tobacco smoke exposure. The matched case control study was conducted among Thai females, aged 17-76 years and living in Bangkok or its surrounding areas. A total of 444 pairs of cases and controls were recruited from the Thai National Cancer Institute. Cases were newly diagnosed and histologically confirmed as breast cancer while controls were selected from healthy women who visited a patient, matched by age ${\pm}5$ years. After obtaining informed consent, tobacco smoke exposure data and information on other potential risk factors were collected by interview. The analysis was performed by conditional logistic regression, and presented with odds ratio (ORs) and 95% confidence intervals(CI). From all subjects, 3.8% of cases and 3.4% of controls were active smokers while 11.0% of cases and 6.1% of controls were passive smokers. The highest to lowest sources of passive tobacco smoke were from spouses (40.8%), the workplace (36.8%) and public areas (26.3%), respectively. After adjusting for other potential risk factors or confounders, females with frequent low-dose passive smoke exposure (${\leq}7$ hours per week) from a spouse or workplace had adjusted odds ratio 3.77 (95%CI=1.11-12.82) and 4.02 (95%CI=1.04-15.50) higher risk of breast cancer compared with non-smokers, respectively. However, this study did not find any association of breast cancer risk in high dose passive tobacco smoke exposure, or a dose response relationship in cumulative passive tobacco smoke exposure per week, or in the active smoker group. In conclusion, passive smoke exposure may be one important risk factor of urban female breast cancer, particularly, from a spouse or workplace. This risk factor highlights the importance of avoiding tobacco smoke exposure as a key measure for breast cancer prevention and control.

• 대한임상독성학회지
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• 제6권2호
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• pp.117-122
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• 2008

Purpose: Surveys on poisoning usually involves intoxication rather than inhalation, skin contact, etc. Therefore, we examined the characteristics of patients who visited the emergency department in an industrial complex after acute industrial exposure to toxic materials. Methods: Medical records of patients exposed to toxic materials in the work places from April, 2006, to March, 2008, were analyzed retrospectively. Inhalation patients due to fire were excluded. Results: Subjects included 66 patients, with a mean age of $35.4{\pm}10.9$ years, mostly men (91%). Toxicity occurred in 51 patients (77%) by contact, 15 patients (23%) by inhalation, and none by oral ingestion. For toxic materials, 10 patients were exposed to hydrofluoric acid, 8 to hydrochloric acid, 7 to sodium hydroxide, 7 to metals, and others. The face and hands were the most frequent exposure site by contact. Most exposures were caused by accidents, with 29 cases (42%) exposed because of carelessness or not wearing protective equipment. Most complaints were pain on exposure site, but 7 of the inhalation patients complained of dyspnea. The majority of patients with contact exposure were discharged after wound care or observation. After inhalation exposure, 1 patient died and 5 patients were admitted to the intensive care unit. Conclusion: Major causes of workplace exposure were not wearing protective equipment or carelessness. Although contact exposures are usually benign, cautious observation and management are required in patients with inhalation exposure.

• Journal of Radiation Protection and Research
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• 제40권3호
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• pp.155-161
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• 2015

Radon is a naturally occurring radioactive gas and a major indoor contribution of exposure to ionizing radiation in dwellings. $^{222}Rn$ is a health hazard gas what is responsible for thousand lung cancer deaths every year. In this study, indoor radon concentrations present in thirty representative houses in Mahallat city, Iran, were determined in order to estimate lung cancer risk associated with residential radon exposure. Long-term passive method, using CR-39, was used to measure the radon concentration. The results showed an association between the age of the dwellings and the indoor radon concentration that was found, in that the concentration of radon tended to increase as the age of the dwelling also increased. The indoor radon concentrations were calculated to be within the range of $23{\pm}2$ to $350{\pm}26Bq{\cdot}m^{-3}$, with an average of $158Bq{\cdot}m^{-3}$. The annual effective dose from inhaled radon and its decay products was calculated between $0.8{\pm}0.1$ and $12.3{\pm}0.9mSv{\cdot}y^{-1}$, with an average of $5.5mSv{\cdot}y^{-1}$. By taking into consideration the EPA recommendation and ICRP statement, the average annual risk of lung cancer from inhaled radon was calculated as 0.09%, 0.06%, 0.01%, and 0.03% for current smokers (CS), those who had ever smoked (ES), never smokers (NS) and the general population, respectively.

• Journal of Preventive Medicine and Public Health
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• 제24권1호
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• pp.86-92
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• 1991

To test if exposure history to rifle fire or cannonade training during military duty can induce hearing loss, history of personal military service and histroy of gunshot exposure were asked to 228 male college students with self -administrative questionnaire. Otoscopic examination and Rinne's test were performed if any abnormal finding was detected by pure-tone audiometry. Average hearing threshold levels of 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz and threshold levels at 4,000 Hz were calculated for 112 students who were remained after exclusion of cases with history of ear disease, of ototoxic drug administration, and of neuropsychiatric disease, and mean of those were compared between group of students who have completed military duty (completed group) and group of those who have not (not-completed group), and between group exposed (exposed group) and group unexposed to gunshot sound (unexposed group). Mean of average hearing threshold level and mean of threshold levels at 4,000 Hz of completed group and those of exposed group were higher than those of not-completed group and unexposed group, respectively. Proportion of cases that average threshold level was greater than 40 dB or threshold levels at 4,000 Hz was greater than 50 dB were higher also in completed group and exposed group than in duty not-completed group and unexposed group, respectively Multiple linear regression analysis including age, duration of military service, degree of gunshot sound exposure as independant variables and average hearing threshold level as dependant variable, was performed in order to estimate the effect of age on hearing, and any considerable effect of age on hearing could not be found. In conclusion, hearing impairment can be induced by rifle fire or cannonade training.

• 한국발생생물학회지:발생과생식
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• 제19권2호
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• pp.69-77
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• 2015

Cell-cell direct communication through channel-forming molecules, connexin (Cx), is essential for a tissue to exchange signaling molecules between neighboring cells and establish unique functional characteristics during postnatal development. The corpus epididymis is a well-known androgen-responsive tissue and involves in proper sperm maturation. In the present research, it was attempted to determine if expression of Cx isoforms in the corpus epididymis in the adult is modulated by exposure to estrogenic or anti-androgenic compound during the early postnatal period. The neonatal male rats at 7 days of age were subcutaneously injected by estradiol benzoate (EB) at low-dose ($0.015{\mu}g/kg$ body weight) or high-dose ($1.5{\mu}g/kg$ body weight) or flutamide (Flu) at low-dose ($500{\mu}g/kg$ body weight) or high-dose (50 mg/kg body weight). The corpus epididymis collected at 4 months of age was subjected to evaluate expressional changes of Cx isoforms by quantitative real-time PCR. Treatment of low-dose EB resulted in increases of Cx32, Cx37, and Cx45 transcript levels, while exposure to high-dose EB decreased expression of Cx26, Cx30.3, Cx31, Cx31.1, Cx32, Cx40, Cx43, and Cx45. Treatments of Flu caused significant decreases of expression of all examined Cx isoforms, except Cx37 and Cx43 shown no expressional change with high-dose Flu treatment. These findings imply that expression of most Cx isoforms present in the corpus epididymis would be transcriptionally regulated by actions of androgen and/or estrogen during postnatal period.

• 기본간호학회지
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• 제13권3호
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• pp.368-375
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• 2006

Purpose: The purpose of this study was to investigate the risk factors of exposure to blood and body fluid by clinical nurses. Method: The participants in this descriptive study were 276 clinical nurses involved in nursing care in a general hospital located in Seoul. The collected data were analyzed using a logistic regression model. Results: The annual exposure rate to blood and body fluid by clinical nurses was 66.3%, and the ratio was higher in the exposed group than in the non-exposed group for nurses under the age of 25, nurses who were unmarried, nurses with low clinical experience, and nurses who work night shifts more than six days a week. Clinical nurses who were unmarried were 1.9 times more likely to have been exposed compared to married nurses. Nurses whose work experience was less than 18 months were 2.7 times more at risk than nurses with more than 18 months of experience. Also, nurses whose fatigue scores were high had an increased chance of exposure (1.9 times). Conclusion: It is necessary to provide intensive training programs for clinical nurses who are in the early months of their career and are likely to be young and unmarried, in order to prevent exposure to blood and body fluid. Administrative supports to self-control and hospital ward operation measures to relieve nurses' fatigue should be provided.

• 대한안전경영과학회지
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• 제17권4호
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• pp.193-198
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• 2015

This study analyzed the total number of 19,636 patients and radiation technologists, 11,433 of male and 8,203 of female by examined body parts, age, types of detectors, the using contrast enhancement and working condition of the technologists, regular staffs or rotation-duty staffs, based on the K-DOS program distributed by FDA with the DLP value of diagnostic evaluation. The result shows that the effective radiation dose was 0.7mSv~41.7mSv for each region and male patients had more radiation exposure than females. And the amount of exposure was also affected by the types and the method of detectors. Furthermore, the regular staffs took the role of helping the patient to get reduced amount of radiation exposure than rotation duty-staffs. Computed tomography (CT) use has increased dramatically over the past several decades. In this reason, to support the patients and the workers' health in the field, the hospitals should apply specialized regular working radiation technologist system and manufacturing companies of those CTs should develop low medical radiation exposure devices.