• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.347-353
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• 2005

Pesticide risk assessment for pesticide operators as well as for consumers has become one of the pesticide regulatory tools to reduce any unreasonable adverse health effects from pesticide use. The risk for pesticide operators can be quantified by comparing the acceptable operator exposure level(AOEL) with exposure level during pesticide application. This study is to evaluate the risk of benzimidazole fungicides application worker. The exposure level of pesticide applicators were calculated using Japanese operator exposure study tested with EPN 45% EC. The AOELs for pesticides were obtained dividing relevant lowest no observed abuse effect levels(NOAELs) for the exposure scenario into uncertainty factor, 100. For the non-cancer and cancer occupational risk assessment, $Q_1^*$ produced by US/EPA and life time average daily dose(LADD) calculated from average daily dose(ADD), treatment days per year, worked years for life time were used. Operator exposure for benzimidazole fungicides application were benomyl 0.2, carbendazim 0.36 and thiophanate-methyl 0.42 mg/kg/day. Short-term AOELs for benomyl, carbendazim and thiophanate-methyl were 0.3, 0.1, and 0.2 mg/kg/day, and long-term AOEL were 0.025, 0.025, 0.08 mg/kg/day, respectively. LADDs were benomyl 0.0038, carbendazim 0.0067, thiophanate-methyl 0.0081 mg/kg/day. The ratios of exposure to AOEL were $0.28{\sim}1.5$ for short-term and $3.73{\sim}9.88$ for long-term. Cancer risk for operator were $9.12{\times}10^{-6}$ for benomyl, $1.61{\times}10^{-5}$ for carbendazim and $1.13{\times}10^{-4}$ for thiophanate-methyl by the standard application scenario. The result showed 3 fungicides exceed the risk criteria, $1.0{\times}10^{-6}$. The above risk assessments were based upon conservative assumptions and therefore are believed to be protective of the applicator. To refine the risk at the more actual conditions, further risk assessment with more realistic data would be needed.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.118-120
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• 2005

본 연구는 송전선 주변 거주 초등학교 학생들을 대상으로 시간 활동 행태에 따른 여러 미세환경, 즉 주거환경, 학교환경, 학원, PC방, 교통에서의 자기장 노출수준을 다양한 매트릭스를 이용하여 비교 ${\cdot}$ 분석함으로써 연구대상자들의 활동한 미세환경 인자를 평가하여 시간별행동양식에 따른 24 시간 개인노출수준을 시간가중 평균모델을 이용하여 예측하고 비교 ${\cdot}$ 평가하였다. 본 연구는 154kV 고압 송전선로가 초등학교 옥상을 통과하는 B 초등학교 125명을 최종 선정하여 2003년 7월부터 2004년 2월 말까지 실시하였으며, 시간가중평균모델을 바탕으로 하여 자기장 노출량 평가 모델을 개발하였다. 전체 연구대상자들의 미세환경 내 평균 자기장값으로 계산한 시간가중 평균모델 (TWA model II)을 이용하여 예측된 자기장 개인노출수준을 보면 실측된 개인노출수준과 약간의 상관성을 보였다(Pearson r = 0.34 ${\sim}$ 0.35). Spot 측정한 값과 24 시간 stationary 측정값을 이용한 TWA Model II-2로 예측한 결과 실측값간의 상관성이 0.65 ${\sim}$ 0.85 로 산출되어 TWA 모델 중 가장 실측값을 잘 설명하였다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.126-133
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• 2015

연구목적: 이 연구는 노동부의 보건진단 명령에 의해 유리섬유 강화플라스틱(FRP)을 이용한 이중벽 탱크 제조 사업장의 적층 공정 근로자들을 대상으로 스티렌 노출 특성을 평가하기 위해 수행되었다. 연구방법: 스티렌의 주요발생원 파악을 위해 불포화 폴리에스테르 수지(UPR), 경화제, 조색제, 세척액 등의 원료 내 스티렌 함유량을 가스크로마토그래피 질량분석기(GC-MS)를 이용하여 분석하였다. FRP 적층 공정에 근무하는 작업자들을 대상으로 NIOSH 1501 공정시험법에 의해 공기 중 스티렌 노출 농도에 대한 개인노출 평가를 실시하였고, 생물학적 노출 지표로 뇨 중 만델릭산을 채취한 후 고성능액체크로마토그래피(HPLC)로 분석하였다. 또한 각 직무 특성과 단위작업 중심으로 스티렌에 대한 단시간 노출평가를 수행하였다. 연구결과: 스티렌의 함유량이 가장 많은 주요 원료는 중량비율로37%의 스티렌이 함유된 UPR이었다. 적층 공정의 FRP분무 작업자와 보조 작업자들 모두 스티렌의 8시간 가중평균 노출기준(20 ppm)을 초과하였다. 단시간 노출평가 결과 FRP분무 작업자의 경우 45.9 ppm에서 86.1 ppm 수준으로 FRP를 사용하지 않는 작업보다 통계적으로 유의하게 높은 수준이었다(P<0.01). 가장 높은 수준의 스티렌에 노출되는 단위작업은 FRP를 이용하여 1차 코팅 하는 작업으로 특별한 관리가 필요하였다. 결론: 보건진단을 위해 실시한 이중벽 탱크 제조 사업장의FRP 적층 공정 작업자의 스티렌 노출수준은 노출기준을 초과할 정도로 높은 수준이었다. 그러나 탱크를 천장에 매달고 돌리면서 적층작업을 수행하기 때문에 적절한 국소환기 시스템을 구축하는데 어려움이 있다. 따라서 적절한 방독마스크 착용으로 스티렌 노출 예방이 필요하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.207-212
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• 2006

A variety of wireless devices are commercially available now. Most of studies, however, have been directed to the biological effects of mobile-phone EMF. In this paper, dosimetric analysis for wireless devices of head-mounted display type and a wristwatch type were made to investigate possible biological effects of these devices. SAR(Specific Absorption Rate) distributions were calculated using FDTD(Finite Difference Time Domain) method, for adult human models such as standard Korean human model and VHP(Visible Human Project) model, as well as scaled child models. Measurements were also performed for SAM phantom wearing a simplified prototype for a wireless device for validation of the simulation results. It has been found that children are more vulnerable to such exposure, and these devices could cause some biological effects even for relatively lower power compared to conventional mobile pones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1158-1166
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• 2013

SAR calculation method following the Mobi-Kids study protocol is analyzed and evaluation method of cumulative RF dose from mobile phones which have been used by a subject of case and control groups is proposed. An SAR database is built by calculating SAR distributions in 4 head models at different ages for representative phone models with the same conducted power. To obtain SAR distribution in a subject's head for a specific commercial phone which had/have been used by him/her, an SAR correction factor using SAR compliance test results is determined. Cumulative dose is calculated by considering mobile phone characteristics and use pattern such as call time and laterality(right and left).

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.357-365
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• 2011

Exposure measurement of agricultural worker to pesticide is one of important part of health risk assessment of pesticide. Therefore exposure matrices, apparatus, instruments and methods must be validated in advance to field experiment. In this study, method validation with an organophosphorus insecticide fenthion was carried out for exposure monitoring of agricultural worker. LOD and LOQ were 0.01 and 0.05 ng, respectively. Calibration curve linearity ($R^2$ > 0.999) and reproducibility (C.V. < 3%) were also excellent. Recovery at LOQ, 10LOQ and 100LOQ levels from gloves, socks, mask, patch, solid sorbent, glass fiber filter was 76~113% (C.V. < 3%). Trapping efficiency was 95~105% while no breakthrough was observed. Method validation for the exposure monitoring was established successfully through several experiments. Such method validation can be usually performed in laboratory and not much different for each pesticide so that, this techniques will be applied widely in research for pesticide exposure monitoring by combination with body surface area and respiration rates.

• Journal of Radiation Protection and Research
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• v.26 no.2
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• pp.79-86
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• 2001

This study presents the quantitative exposure assessment of indoor radon released from groundwater. Most of the Indoor radon comes directly from soil beneath the basement or foundation. Recently, radon in groundwater releases to indoor air whenever the water is used and contributes to the total inhalation risk from indoor air. This study first develops a mathematical model to describe the transfer and distribution of radon released from groundwater in a house. Then, daily human exposures through inhalation or such radon are estimated with the model for an male adult based on two sets of exposure scenarios. The results obtained from the study would help increase the understanding of risk assessment issues associated with the indoor radon released from groundwater.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.969-976
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• 2004

The wide and growing use of cellular phones has raised the question about the possible health risks associated with radio-frequency electromagnetic fields. It would be helpful for phone users to blow the exposure levels during cellular phone use. But it is very difficult to recognize the amount of exposure, because measuring accurate level of RF is a difficult matter. In this study, we developed a model to estimate the exposure level and the individual risk of exposure by utilizing the available informations that we can get. We used such parameters as usage time a day, total using period, distance between cellular phone and head, slope of cellular phone, hands-free usage, antenna pulled out or not SAR(Specific Absorption Rate) of cellular phone, and flip or folder type. We proposed a model presenting individual risk of RF exposure from level 0 to 10 by using a neural network.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.50-59
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• 2013

This study was performed in order to assess the risk of korean orchard worker due to pesticide exposure. The amount of pesticide exposure was calculated based on the informations of 97 kind of items that are used the form of a spraying in Korean orchard. The risks of these pesticides were assessed to compare the exposure amount with AOEL (acceptable operator exposure level) which was released form developed countries. When the operator sprayed pesticides using speed sprayer, 74.2% of pesticide items showed the risk for operator if the operator have not worn the personal protective equipment (PPE), and 42.3% of pesticide items showed the risk for operator if the operator have worn the PPE. In case of using motor sprayer, 64.1% of pesticide items showed the risk for operator if the operator have not worn the PPE, and 19.4% of pesticide items showed the risk for operator if the operator have worn the PPE. This result was indicated that the risk of pesticide against the operator was very high in korean orchard operator.

• The Korean Journal of Ecology
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• v.24 no.1
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• pp.35-43
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• 2001

Accumulation, elimination and subcellular distribution of heavy metals in Littorina brevicula exposed to cadmium and zinc separately and concurrently were investigated. When the winkles had been exposed to 400 ㎍/L CdCl₂ and 3000 ㎍/l ZnSO₄ separately for 90 days, each of the metal body burden in the whole sofl parts increased in proportion to time of exposure until 70 days. But it didn't increase after 70 days. But when the winkles had been exposed to cadmium and zinc simultaneously, cadmium body burden decreased but zinc body burden increased as compared to the winkles exposed to each of the metal. We also found that cadmium accumulated in the winkles was not depurated for 42 days, but zinc accumulated in them was depurated. Especially, zinc was depurated faster when they had been exposed to mixture of cadmium and zinc. After the winkles had been exposed to cadmium and zinc separately for 70 days, about 60% cadmium of the total body burden was associated with the soluble fraction, while about 75% zinc of the total body burden was associated with insoluble fraction. And these trends of metal partitioning did not alter when the winkles had been exposed to metal mixture. After the soluble fraction applied to gel-filtration chromatography column, the distribution patterns of cadmium and zinc associated with proteins or ligands were different each other. Most of cadmium (＞90%) in the soluble fraction was bound to MBP-1 (Metal-binding protein-1), about 6.5 kDa), while zinc was distributed evenly to HMW (High molecular weight fraction, >60 kDa), MBP-1, MBP-2 (about 5 kDa), LMW (Low molecular weight fraction, <1 kDa).