• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.2
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• pp.102-110
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• 2010

Personal exposure relies on characteristics of time activity patterns of the population of concern as human activities impact the timing, location, and level of personal exposure. The information about time spent in microenvironments plays a critical role for personal exposure to air pollutants. It is useful to determine the precise times of the day that the subjects are in certain locations or engaging in specific activities because exposure to some air pollutants can depend on temporal trends. This study investigated time activity pattern for workers of Korean population over 19 years old with 8,778 workers in weekday. The residential indoor times were 12 hours. Time activity was different by gender and the mean times stayed at home in weekday were 12.9 hours in female and 11.42 hours in male, respectively. The major factors on residential indoor time and workplace time were age, monthly income, occupation and industry type, work position, education, and gender. Considering shorter than those in other countries, Korean workers spent less time at home after the working hours. Determinants of time activity pattern need to be taken into account in exposure assessment, epidemiological analyses, exposure simulations, as well as in the development of preventive strategies. Since there are substantial difference of Korean worker activity pattern, this information can be critical for exposure assessment in Korea.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.324-333
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• 2017

Objectives: The purpose of this study was to assess the correlation relationship between personal exposure and urinary hippuric acid in biological monitoring for airborne toluene in an industrial complex and in general environments. Methods: Personal exposure to toluene and its metabolite, hippuric acid, in urine were simultaneously measured in occupational environments area near an industrial complex and in general environments. The study subjects were divided into three types: 137 workers who use organic solvents in the workplace, 210 residents living near a dyeing industrial complex, and 379 residents living in general environments. The toluene exposures of workers and residents were measured by a passive sampler for four days. The urine of participants was sampled when the passive samplers of personal exposure were collected. Results: The toluene and hippuric acid concentrations of workers were the highest, followed by the concentrations of residents living near a dyeing industrial complex and residents living in general environments. The coefficient of correlation between the concentrations of toluene and hippuric acid among workers was 0.749 (p<0.01) in the workplace. On the contrary, correlations between the concentrations of toluene and hippuric acid among residents living near a dyeing industrial complex and residents living in general environments were all not significant. The relationship between the concentrations of hippuric acid and toluene in three types could be described by the exponential growth model. Conclusions: This study analyzed the relationships between toluene exposure and the concentrations of hippuric acid in urine in high, middle, and low exposure environments, and could be described by the exponential growth model.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.4
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• pp.334-345
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• 2006

The objectives of this study were to analyze and compare 24 hrs personal exposure levels of MF at microenvironments such as home, school, educational institute, internet pc game room, transportation, and other places according to time activity patterns using various metrics for children attending the primary schools located near and away from the power lines, and to characterize the major microenvironments and impact factors attributed personal exposure level. The study was carried out for 44 children attending a primary school away from the lines(school A) and 125 children attending a school away from 154 kV power lines(school B), all who aged 12 years and were 6 grade, from July 2003 to December 2003. All participants filled in a questionnaire about characteristics, residence, use of electrical appliances and others. Children wore a small satchel in which EMDEX II and Lite (Enertech, Co. Ltd) and a diary of activity list for period of registration in 20 minutes blocks. All statistical calculations were made with the SAS System, Releas 6.12. The summary of results was presented below. First, about the characteristics of subjects, there no differences between two groups. The subject almost spent about 56 % of their time at home and about 20~25 % of their time at school. Fifty percent of children spent 2 hours at private educational institutes. Second, the personal exposure measurements of children in school B was statistically higher than those of children in school A by various metrics such as arithmetic mean, geometric mean, percentile(5, 25, 50, 75, 95), maximum, rate of change metric, constant field metric. The arithmetic and geometric mean magnetic fields during the time the children were at school B were 0.98 and $0.86{\mu}T$ and were about 23 times higher than those of children were at school A. In conclusion, the significant major determinants of personal exposure level is the distance from the power line to microenvironments.

• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.1-7
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• 2000

There is increasing evidence suggestion that passive smoking increases the risk of lung cancer and other disease, though the potential health effects of exposure to environmental tobacco smoke (ETS) is a controversial subject. Since smoking in restaurant is prevalent in Korea, the concern on passive smoking exposure of non-smoking service-workers has been requested. ETS exposure of non-smoking service-workers at restaurant was assessed because they hare spent their times in restaurant indoors. The purpose of this study was feasibility of nitrogen dioxide($NO_2$) as exposure marker of ETS. The results of the study were as follows; 1. Average $NO_2$ concentrations in indoor and outdoor t restaurants were 57.1ppb(${\pm}12.4$) and 54.29ppb(${\pm}9.54$), respectively. Comparing office-workers, service-workers at restaurants were exposured highly. 2. The personal $NO_2$ measurement as exposure marker of ETS could cause the exposure error because $NO_2$ can be generated by combustion appliances in indoor. 3. Service-workers spent their most time(86.6%) in indoor. Mean time spent at restaurant indoors and at home was 9.4 hours and 10.9 hours, respectively. 4. Personal $NO_2$ levels correlated with indoor $NO_2$ concentrations of restaurant (r=0.70) and of their home (r=0.52) rather than of outdoor $NO_2$ concentration of restaurant (r=0.35). The cause of personal $NO_2$ exposure of non-smoking service-workers were considered as smoking of guests and combustion appliance indoors. 5. personal $NO_2$ exposures were estimated using Monte-Carlo simulation and time-weighted model. Estimated personal $NO_2$ level was 47.25ppb(${\pm}8.3$).

• Journal of Environmental Health Sciences
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• v.42 no.5
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• pp.314-323
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• 2016

Objectives: Time location data are critical for accurately estimating personal exposures. This review papers summarized various measurement methods of time location pattern for air pollution exposure assessment. Methods: Forty manuscripts (papers, books and reports) were reviewed to comprehensively describe time location measurement methods. Results: This review included traditional methods such as time activity diary, questionnaire, observation, focus group and newly developed technical methods including global positioning system, web, radio frequency identification and ultrasound detection. Some research applied a combination of methods. Conclusion: Although various methods have been used to collect time location data, further development of accurate measurement methods for time location data is needed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.35-40
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• 2013

Objectives: Asbestos contents of crushed serpentine rocks and airborne fiber concentrations of workers were determined at two serpentine quarries and a steel mill. Methods: Bulk samples of uncrushed and crushed serpentine rocks were collected and analyzed by PLM and TEM. Airborne asbestos samples were collected from the breathing zone of workers and the vicinity of working area and analyzed by PCM and TEM. Results: Chrysotile was identified with antigorite, lizardite and non-asbestiform actinolite in bulk samples. The arithmetic means of chrysotile contents in crushed serpentines were 0.11, 0.01, 0.42%(W/W) by quarry A, quarry B and a steel mill, respectively. The asbestos concentrations of all personal samples were less than 0.1 f/cc which is the permissible exposure limit of workers in Korea. The arithmetic means of airborne asbestos concentrations were 0.017 f/cc and 0.009 f/cc in personal samples collected from two serpentine quarries. The asbestos concentrations of all personal samples collected from a steel mill were less than LODs by PCM analysis but asbestos was detected in area samples by TEM. By the job tasks of serpentine quarries, crusher/separator operation generated the highest exposure to airborne asbestos. Conclusions: Although chrysotile contents in crushed serpentines of quarries were less the permissible level, the highest exposure of workers in serpentine quarries reached up to 76% of the permissible level of airborne asbestos. There were also possibilities of occupational exposure to airborne asbestos in a steel mill. The present exposure study should encourage further survey and occupational control of quarries producing serpentine or other types of asbestos-bearing rocks.

• Journal of Korean Clinical Health Science
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• v.2 no.1
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• pp.25-34
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• 2014

Purpose. The checked of perception for the protection of personal medical information of EMT student and Nursing student. Methods. Nursing students and EMT students 200 questionnaires were collected and Frequency analysis, Chi-square test, one-way ANOVA was performed for using the Windows SPSS(ver. 12.0). Results. Most of the subjects were aware of the protection law of personal information and Infringement of the privacy of personal information will be exposed. also, Education is needed privacy(EMT students $3.84{\pm}0.96$, Nursing students $3.73{\pm}0.99$). EMT($3.99{\pm}1.00$) and Nursing($4.07{\pm}0.94$)students due to exposure to both the patient's personal information privacy was violated would get recognized. Exposure to the computerization of information privacy will be exploited in other agencies(EMT students $3.78{\pm}0.88$, Nursing students $3.95{\pm}0.94$) was called. Conclusions. For the protection of personal health information, education needs to be expanded.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.81-90
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• 2023

Climate change has resulted in increased frequency and intensity of heat waves, which poses a significant threat to the health and safety of construction workers, particularly those engaged in labor-intensive and heat-stress vulnerable working environments. To address this challenge, this study aimed to propose an interpretable machine learning approach for forecasting personal heat strain by considering the cumulative effect of heat exposure as a situational variable, which has not been taken into account in the existing approach. As a result, the proposed model, which incorporated the cumulative working time along with environmental and personal variables, was found to have superior forecast performance and explanatory power. Specifically, the proposed Multi-Layer Perceptron (MLP) model achieved a Mean Absolute Error (MAE) of 0.034 (℃) and an R-squared of 99.3% (0.933). Feature importance analysis revealed that the cumulative working time, as a situational variable, had the most significant impact on personal heat strain. These findings highlight the importance of systematic management of personal heat strain at construction sites by comprehensively considering the cumulative working time as a situational variable as well as environmental and personal variables. This study provided a valuable contribution to the construction industry by offering a reliable and accurate heat strain forecasting model, enhancing the health and safety of construction workers.

• Journal of Preventive Medicine and Public Health
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• v.23 no.2 s.30
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• pp.201-206
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• 1990

The exposures to carbamate pesticides (BPMC specifically) of agricultural workers were estimated by collecting pesticide in air by personal sampler and by analyzing with gas chromatography. Data revealed that the highest BPMC concentration in the aspirated air was $7.7mg/m^3$. Concentrations were generally higher in the group whose spray conditions were controlled than the group uncontrolled. Actual concentations were relatively lower than the values predicted theoretically. These findings suggest that personal sampler be useful in the estimation of pesticide exposure.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.472-474
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• 2002

The objective of this survey is to characterize the personal magnetic field exposure of the Korean population. The participants in the survey on magnetic field exposure were selected randomly by occupation. In this first step survey, the number of participant is 108 and for the second step, about 400 participants will be surveyed in the near future. The survey is the first significant study that quantifies the exposure of the general population for the entire day, not only for the time spent in one's bed but also for the time at work in Korea.