• 대한의생명과학회지
• /
• 제22권4호
• /
• pp.140-149
• /
• 2016

All pesticides must be assessed strictly whether safe or not when agricultural operators are exposed to the pesticides in farmland. A pesticide is commonly regarded as safe when estimated dermal absorption amount is lower than the acceptable operator's exposure level (AOEL). In this study, dermal absorption rate of chlorpyrifos, a widely used organophosphate insecticide, was investigated using rat dermal tissue model. Chlorpyrifos wettable powder solved in water (250, 500 and 2,500 ppm) was applied to freshly excised rat dermal slices ($341{\sim}413{\mu}m$ thickness) on static Franz diffusion cells at $32^{\circ}C$ for 6 hours. After exposure period of 6 hours, and then washing-at residual amount of chlorpyrifos was analyzed in dermal tissues, tape strips, washing solution, washing swabs of receptor bottles and receptor fluids at 1, 2, 4, 8 and 24 hours. Chlorpyrifos was only detected in dermal tissue but not found in receptor fluid at each concentration and time point, and the absorption rate of 250, 500 and 2,500 ppm was 2.36%, 1.96% and 1.69%, respectively. The estimated exposure level of chlorpyrifos was calculated as 0.012 mg/kg bw/day. The health risk for farmers in this condition is a level of concern because the estimated exposure level is 12 times higher than AOEL 0.001 mg/kg bw/day. However, actual health risk will be alleviated than estimated because absorbed chlorpyrifos is not permeated into internal body system and only retained in skin layer.

• 한국콘텐츠학회논문지
• /
• 제17권7호
• /
• pp.498-504
• /
• 2017

치아를 칫솔질하거나 치약을 사용하는 것과 같은 구강 건강 행위는 구강 건강을 개선하며, 따라서 삶의 질을 향상시키는 중요한 부분이다. 그러나 화학 물질에 대한 연구도 필요한 실정이다. 따라서 본 연구는 구강 건강 행위로 인해 야기되어지는 불소 노출에 미치는 요인을 조사하여 정확한 구강 건강 지침을 제공하고자 한다. ConsExpo 5.0 모델에서 불소 화합물의 경구 노출을 적용한 결과, 일일 불소 인체노출량 추정은 성인남성의 모델 결과 oral external dose는 0.000196 mg/kg, oral acute(internal) dose는 0.000196 mg/kg, oral chronic(internal)dose는 0.000465 mg/kg/day로 추정되었다. 성인여성은 연구결과 oral external dose는 $4.1{\times}10^{-6}mg/kg$, oral acute(internal) dose $4.1{\times}10^{-6}mg/kg$, oral chronic(internal) dose $9.99{\times}10^{-6}mg/kg/day$로 추정되었다.

• 한국환경과학회지
• /
• 제18권10호
• /
• pp.1123-1134
• /
• 2009

This study was designed to evaluate qualitatively and quantitatively the pollutant compositions, which were emitted from three types of mosquito repellents(MRs)(mat-, liquid-vaporized, and coil-type) by utilizing a 50-L environmental chamber. A qualitative analysis revealed that 42 compounds were detected on the gas chromatography/mass spectrometer system, and that the detection frequency depended upon chemical types. Nine of the 42 compounds exhibited a detection frequency of 100%. Four aromatic compounds(benzene, ethyl benzene, toluene, and xylene) were detected in all test MRs. The concentration equilibriums in the environmental chamber were achieved within 180 min after sample introduction. The coil-type MR represented higher chamber concentrations as compared with the mat- or liquid-vaporized-type MR, with respect to the target compounds except for naphthalene. In particular, the chamber concentrations of ethyl benzene, associated with the use of coil-type MR, were between 0.9 and $65\;mg\;m^{-3}$ whereas those of mat- and liquid-vaporized-type MRs we~e between 0.5 and $2.0\;mg\;m^{-3}$and 0.3 and $1.4\;mg\;m^{-3}$, respectively. However, naphthalene concentrations in the chamber, where a liquid-vaporized-type MR was placed, were measured as between 17.8 and $56.3\;mg\;m^{-3}$, but not detected in the chamber, where a mat- or coil-type MR was placed. The empirical model fitted well with the time-series concentrations in the environmental chamber(in most cases, determination coefficient, $R^2$ ≿ 0.9), thereby suggesting that the model was suitable for testing emissions. In regards to the target compounds except for benzene, although they were emitted from the MRs, health risk from individual exposure to them were estimated not to be significant when comparing exposure levels with no observed adverse exposure levels or lowest observed adverse exposure levels of corresponding compounds. However, it was concluded that the use of MRs could be an important indoor source as regards benzene.

• 환경영향평가
• /
• 제10권3호
• /
• pp.211-221
• /
• 2001

Recognizing interaction between the environment and humans, the EIA(environmental impact assessment) movement has sought to promote more environmentally sound and informed decisions for the sake of human welfare. Therefore, most EIA programs require the consideration of human health impacts. Yet relatively few EIA documents adequately address those impacts. This study was carried out to investigate the role of EIA for reuniting the environment and human health, for preventing and reducing significant health risks, and for improving human health impact assessment by means of risk assessment. Risk assessment consists of 4 components; hazard identification, dose-response assessment, exposure assessment and risk characterization. Since most people spent their times in indoor, indoor air quality modelling can be used in exposure assessment and risk assessment. In this study, indoor $NO_2$ concentration and personal $NO_2$ exposure were estimated by Box Model using mass balance equation and time weighted average, respectively. The estimated indoor $NO_2$ concentration and the personal $NO_2$ exposure were compared by those measured, respectively. Subsequntly, health effect was assessed with these results. Consequently, exposure assessment and risk assessment using indoor air quality model may be considered to be applicable to EIA.

• 한국치위생학회지
• /
• 제20권3호
• /
• pp.269-279
• /
• 2020

Objectives: Previous studies have reported inconsistent findings in the association between dental diagnostic X-ray exposure and thyroid cancer. This study was a meta-analysis of case-control studies evaluating the association between exposure to dental radiation and the thyroid cancer risk. Methods: We searched the PubMed and EMBASE databases to identify studies on dental radiation and thyroid cancer risks that were published up to September 2018. Quality of studies was assessed using the Newcastle-Ottawa scale. A fixed-effects model was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs) using STATA 14.0. Potential publication biases were evaluated using Egger's test and Begg's funnel plot. Results: From the literature search, we included six case-control studies in this meta-analysis. The meta-analysis using the fixed-effects model found that dental X-ray exposure was associated with 2.34 times increased risk for thyroid cancer (OR=2.34, 95% CI=1.79-3.21). There was no heterogeneity in the data (p=0.662, I² =0%). Egger's test showed that there was no publication bias (p=0.532). Conclusions: This meta-analysis confirmed the association of dental X-ray exposure and thyroid cancer risk. The current results underscore the importance of applying safety regulations at dental clinics to protect thyroid glands during dental radiography examinations.

• Safety and Health at Work
• /
• 제14권2호
• /
• pp.237-242
• /
• 2023

Background: This study evaluated occupational exposure levels of doxorubicin in healthcare workers performing rotational intraperitoneal pressurized aerosol chemotherapy (PIPAC) procedures. Methods: All samples were collected during PIPAC procedures applying doxorubicin to an experimental animal model (pigs). All procedures were applied to seven pigs, each for approximately 44 min. Surface samples (n = 51) were obtained from substances contaminating the PIPAC devices, surrounding objects, and protective equipment. Airborne samples were also collected around the operating table (n = 39). All samples were analyzed using ultra-high performance liquid chromatography-mass spectrometry. Results: Among the surface samples, doxorubicin was detected in only five samples (9.8%) that were directly exposed to antineoplastic drug aerosols in the abdominal cavity originating from PIPAC devices. The telescopes showed concentrations of 0.48-5.44 ng/cm² and the trocar showed 0.98 ng/cm² in the region where the spraying nozzles were inserted. The syringe line connector showed a maximum concentration of 181.07 ng/cm², following a leakage. Contamination was not detected on the surgeons' gloves or shoes. Objects surrounding the operating table, including tables, operating lights, entrance doors, and trocar holders, were found to be uncontaminated. All air samples collected at locations where healthcare workers performed procedures were found to be uncontaminated. Conclusions: Most air and surface samples were uncontaminated or showed very low doxorubicin concentrations during PIPAC procedures. However, there remains a potential for leakage, in which case dermal exposure may occur. Safety protocols related to leakage accidents, selection of appropriate protective equipment, and the use of disposable devices are necessary to prevent occupational exposure.

• 아동학회지
• /
• 제32권3호
• /
• pp.91-105
• /
• 2011

The purpose of this study was to investigate the relationship between sexual development, sensation seeking traits, exposure to pornographic media, peer conformity, and potential delinquency on the part of Korean middle school students. In order to verify the model, we used structural equation model (SEM) analysis. 603 adolescents were participated in the study. The results were as follows; first, both male and female models goodness of fit and significant paths was proven. Second, it was also found that gender difference existed in the model. The implications of this study and the suggestions for future research were also discussed.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.136-141
• /
• 2004

The gear in various mechanical components easily occurs at damages by the external torque. The main failure modes of the gear are surface pitting with the tooth surface and breakage with tooth root by caused fatigue. Therefore, the gear is very important role in the reliability research since it may cause fatal damage of entire system such as the gear box in automobile transmission. In this study, the failure mode of the gear was analyzed and accelerated durability analysis was employed for the life estimation of spur gears. In the case of assumed load spectrums, the reliability of spur gears was evaluated by inverse power law-Weibull accelerated life test model with cumulative damage exposure.

• 한국대기환경학회지
• /
• 제5권2호
• /
• pp.30-35
• /
• 1989

To effectively develop and evaluate air pollution control measures, health risk rates due to air pollution must be identified. This article describes the application of a visual analysis and an air pollution-health risk model for determining the impacts of carbon monoxide (CO) exposure on angina pectoris patients in a metropolitan area. The procedures used for analyzing the relationship between CO exposure and the related increase in angina angina attacks for stable angina pectoris patients are described through a case study in the city of Seoul, Korea and the findings show that air-pollution-health risk model and visual analysis can be effective tools for environmental decision-makers, allowing air pollution control scenarios to be developed and evaluated for environmental protection. One of the features of this study is to provide a methodology for translating clinical findings into estimates of the relative contributions of air pollution to all causes of a particular disease. Therefore, there must be appropriate recognition of the uncertainties involved in the study.

• 가정∙방문간호학회지
• /
• 제30권2호
• /
• pp.202-215
• /
• 2023

Purpose: This study attempted to determine the factors related to behaviors of reducing exposure to endocrine disrupting chemicals (BRE to EDCs) in pregnancy, based on the PRECEDE model. Methods: A cross-sectional survey was conducted with participants (N=239) who met the medical records and eligibility criteria from the Women's Hospital and Public Health Center. Data were collected using a specially-designed questionnaire based on the PRECEDE model and included BRE to EDCs predisposing factors, reinforcing factors, and enabling factors. The data were analyzed using the chi-square test, independent t-test, one way ANOVA, Pearson's correlation coefficients and a hierarchical multiple regression analysis. Results: In Model I it was found that participation in prenatal education influenced the BRE to EDCs significantly; and a regression showed that the determinant variables accounted for 3.4%. In Model II, the predisposing factors of perceived barriers of BRE to EDCs and environmental self-efficacy were added. It was shown that they significantly influenced BRE to EDCs in the order named, and a regression revealed that increases in the determinant variables accounted for 22.5%. In Model III, to which enabling factors were added, the information acquisition experience of BRE to EDCs interacted significantly with BRE to EDCs and a regression showed an increase in the determinant variables accounting for 25.3%. Conclusion: The results of this study, the content of endocrine disruptors must be included in the prenatal care education program for pregnant women, and it should be composed of contents that can reduce the perceived obstacle to BRE to EDCs, enhance the environmental self-efficacy, and provide the information in regard to reducing exposure to EDCs.