• Journal of Preventive Medicine and Public Health
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• v.34 no.1
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• pp.80-88
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• 2001

Objectives : In an epidemiologic study on the health impact of Agent Orange exposure, the valid estimation of exposure level is the most important step. Based on recent studies, we examined the correlation between exposure levels categorized by personal exposure estimates and serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD, Dioxin), exploring the possibility of utilizing the exposure level as a surrogate for the estimate of exposure to agent orange. Methods : During the study period (Jan 1996-Feb 1996), blood specimens of 745 subjects taken randomly among 1,329 persons and kept frozen, were analyzed for 2,3,7,8-TCDO and six other dioxin congeners. The serum dioxin and congeners were measured in 1998 by CDC, adjusted for serum lipids. We categorized the total exposure scores into five groups based on Agent Orange exposure data collected by interview and military records. Pearson and Spearman's correlation coefficients & multiple regression analysis were used to identify the relationship of the exposure level categorized with serum concentration of 2,3,7,8-TCDD, and six other dioxin congeners. Results : Dioxin and the other congeners, except 1,2,4,6,7,8-HpCDD, showed significant correlations to exposure categories (p<0.005): 2,3,7,8-TCDD and OCDD showed positive correlations, whereas the other congeners did negative. The values of 2,3,7,8-TCDD differed according to exposure category and proportionally increased from the low exposure group to the high, a dose-response relationship, even after other possible confounding variables were adjusted for. In multiple regression analysis, age$(\beta=0.033)$, dioxin$(\beta=0.433)$, 1,2,3,7,8-PeCDD$(\beta=-0.998)$, 1,2,3,4,7,8-HxCDD$(\beta=-0.773)$, 1,2,3,6,7,8-HxCDD$(\beta=0.255)$, 1,2,3,7,8,9-HxCDD$(\beta=-3.468)$, 1,2,3,4,6,7,8-HpCDD$(\beta=0.109)$ we re found to be significantly related to the total exposure score(p<0.005). Conclusion : This study demonstrated that the use of such categorizations as a surrogate measure of agent orange exposure in identifying exposure degrees in a health impact study is valid.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.61-73
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• 2011

The aim of this study was to develop a reliable dietary questionnaire to assess human exposure to food-borne hazards. Eleven food-borne hazards were chosen as a priority control list through a literature review and advisory committees. The 11 food-borne hazards were phthalate, aflatoxin, bisphenol A, polycyclic aromatic hydrocarbons, dioxin, polychlorinated biphenyls, mercury, lead, cadmium, arsenic, and acrylamide. The characteristics, exposure level, and paths of these hazards were reviewed, and questionnaire items were identified to assess human exposure from the literature. A questionnaire was developed for each selected food based on its characteristics. Based on the items in the individual questionnaires, a comprehensive questionnaire, which contained demographic characteristics, job information, socioeconomic factors, health related lifestyles, and dietary behaviors, was developed. A 99-item food frequency questionnaire (FFQ) to assess food-borne hazard exposure was also developed. The FFQ included frequency of food intake during the previous year, container type for purchasing and storing food, and cooking method. The questionnaire developed in this study could be applied to assess dietary factors during an exposure assessment of food-borne hazards in a large population. A validation study for the questionnaire is needed before applying it to surveys.

• Journal of radiological science and technology
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• v.5 no.1
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• pp.15-19
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• 1982

Authors made an experiment to know the relation of surface doses and multiple factors of exposure by using grids, fields, tube voltages objects and distances and obtained the results as follows: 1. Surface doses were increased in proportion to the thickness of objects. 2. Surface doses were more influenced when irradiated fields were small and tube voltages were low. 3. Surface doses were a logarthmic proportion to the focus-object distance. 4. Multiple factors of exposure by using grid were under the control of the thickness of objects, irradiated fields and tube voltages but the relation of them were not fixed.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.239-243
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• 1984

The vascular reaction such as the indirect blood pressure and the pulse rate of the tail to the noise were examined in 8 naive Sprague-Dawley rats of both sexes. The sounds used in the experiment were 1KHz and 4 KHz, 95dB pure tone generated by Nagashima Audiometry. The indirect blood pressure and the pulse rate were checked at the rat tail by Polygraph at 5 minutes interval. The results were as follows: 1. The blood pressure and the pulse rate increased maximally 5 minutes after the exposure to both sounds. 2. The blood pressure and the pulse rate returned normal range within 20 minutes after the exposure of both sounds. 3. The increment of the blood pressure and the pulse rate was greater after the sound of 4KHz than after that of 1KHz, but it wasn't statistically significant.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.9.1-9.5
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• 2013

Objectives Geographic Information Systems (GIS) is a powerful tool for assessing exposure in epidemiologic studies. We used GIS to determine the geographic extent of contamination by perfluorooctanoic acid, C8 (PFOA) that was released into the environment from the DuPont Washington Works Facility located in Parkersburg, West Virginia. Methods Paper maps of pipe distribution networks were provided by six local public water districts participating in the community cross-sectional survey, the C8 Health Project. Residential histories were also collected in the survey and geocoded. We integrated the pipe networks and geocoded addresses to determine which addresses were serviced by one of the participating water districts. The GIS-based water district assignment was then compared to the participants' self-reported source of public drinking water. Results There were a total of 151,871 addresses provided by the 48,800 participants of the C8 Health Project that consented to geocoding. We were able to successfully geocode 139,067 (91.6%) addresses, and of these, 118,209 (85.0%) self-reported water sources were confirmed using the GIS-based method of water district assignment. Furthermore, the GIS-based method corrected 20,858 (15.0%) self-reported public drinking water sources. Over half (54%) the participants in the lowest GIS-based exposure group self-reported being in a higher exposed water district. Conclusions Not only were we able to correct erroneous self-reported water sources, we were also able to assign water districts to participants with unknown sources. Without the GIS-based method, the reliance on only self-reported data would have resulted in exposure misclassification.

• Journal of Environmental Health Sciences
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• v.35 no.2
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• pp.100-115
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• 2009

Secondhand smoke (SHS) is one of major public health threats. Since secondhand smoke is complex mixture of toxic chemicals, there has been no standardized method to measure SHS quantitatively. The purpose of this manuscript was to review various quantitative methods to measure SHS. There are two different methods: air monitoring and biological monitoring. Air monitoring methods include exhaled carbon monoxide level, ambient fine particulates, nicotine and 3-ethenylpyridine. Measurement of fine particulates has been utilized due to presence of real-time monitor, while fine particulates can have multiple indoor sources other than SHS. Ambient nicotine and 3-EP are more specific to SHS, although there is no real-time monitor for these chemicals. Biological monitoring methods include nicotine in hair, cotinine in urine, NNK in urine and DNA adducts. Nicotine in hair can provide chronic internal dose, while cotinine in urine can provide acute dose. Since biological monitoring can provide total internal dose, identification of specific exposure source may be difficult. NNK in urine can indicate carcinogenicity of the SHS exposure. DNA adducts can provide overall cancer causing exposure, but not specific to SHS. While there are many quantitative methods to measure SHS, selection of appropriate method should be based on purposes of assessment. Application of accurate and appropriate exposure assessment method is important for understanding health effects and establishing appropriate control measures.

• Journal of Environmental Health Sciences
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• v.15 no.1
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• pp.19-32
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• 1989

This study was performed to evaluate the worker exposure to asbestos fibers in automobile repair shop and brake lining store from August 11 to October 21, 1988. In addition, the exposure of general population near the brake lining store was also evaluated. Results of this study were as follows. 1. Worker exposure level to asbestos fibers in automobile repair shop was 0.1 fibers/cc, well below the Korean standard of 2 fibers/cc, and a half of the U.S. standard of 0.2 fibers/cc. 2. Average worker exposure level to asbestos fibers in brake lining store was 0.35 fibers/cc, which was within the Korean standard of 2 fibers/cc, but exceeded the U.S. standard of 0.2 fibers/cc. 3. Worker exposure levels during the removal of brake dust with the compressed air blowing and the dry brushing were approximately 4 fibers/cc and 0.2 fibers/cc, respectively. During grinding of brake linings with sand paper, asbestos exposure level was 0.3 fibers/cc. 4. Ambient asbestos concentrations outside the brake lining store were 0.1 fibers/cc at the distance of 3-4 m, and 0.01 fibers/cc at the distance of 30 m.

• Journal of radiological science and technology
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• v.7 no.1
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• pp.67-70
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• 1984

Radiographic units have changeable factors in x-ray outputs, Therefore, an exposure factor by basic experimental study must be made out about each x-ray installation, but this is very intricate methods and not a practical business. Authors tried out a new method to make simple exposure factors. The first, we had a experimental object radiograph taken to find the output of each radiographic unit. The second, by obtained x-ray density we found the difference in x-ray output. and lastly, we made a new and simple correction method to use the obtained output and x-ray density.

• Journal of Preventive Medicine and Public Health
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• v.46 no.4
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• pp.211-211
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• 2013

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.12a
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• pp.81-82
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• 2004