• Environmental Analysis Health and Toxicology
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• 제19권4호
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• pp.367-373
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• 2004

Mancozeb, a polymeric complex of zinc and manganese salts of ethylene bisthiocarbamate (EBDC), is used widely in agriculture as fungicides, insecticides, and herbicides. Mancozeb can be occupationally and environmentally exposed to human and has been reported to induce estrogenic activity, therein it is considered as an endocrine disrupter. After female ICR mice were treated Mancozeb orally at the doses of 250, 1,000 and 1,500 mg/kg/day for consecutive 30 day, we investigated the effects of Mancozeb on the immunopathological parameters (body-, thymus-, spleen-, liver- and kidny-weight, splenic cellularity, hematological parameters) and mitogen (Con A, LPS)-induced splenocyte proliferation (SP). Liver- and kidney- weight were increased, but body- and thymus-weight, number of splenocytes and WBC were decreased, when compared with control group. When splenocytes isolated from the mice exposed to Mancozeb for 30 days were cultured in presence of mitogens, the SP against Con A was significantly and dose-dependently decreased and the SP against LPS was also slightly decreased. Our present results indicate that subacute exposure of Mancozeb to mice might show immunotoxic effect.

• 생태와환경
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• 제50권1호
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• pp.16-28
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• 2017

In an aquatic environment, toxicity of metals to organisms depends on external factors (type of metal, exposure concentration and duration, environmental parameters, and water quality) and intracellular processes(metal-binding sites and detoxification). Toxicity of copper(Cu) on the marine microalga Tetraselmis suecica was investigated in this study. Dose-dependent (Cu concentration dependent) inhibition of growth and cell division, as well as, variation of intra- and extra-cellular Cu, Fe and Zn content was observed. T. suecica was sensitive to Cu; the 96 h $EC_{50}$ (concentration to inhibit growth-rate by 50%) of growth rate (${\mu}$) ($21.73{\mu}M\;L^{-1}$), cell division $day^{-1}$ ($18.39{\mu}M\;L^{-1}$), and cells $mL^{-1}$ ($13.25{\mu}M\;L^{-1}$) demonstrate the toxicity of Cu on this microalga. High intra-($19.86Pg\;cell^{-1}$) and extra-cellular($54.73Pg\;cell^{-1}$) Cu concentrations were recorded, on exposure to 24.3 and $72.9{\mu}M\;L^{-1}$ of Cu.

• Corrosion Science and Technology
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• 제18권3호
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• pp.86-91
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• 2019

Generally, atmospheric corrosion is the electrochemical degradation of metal that can be caused by various corrosion factors of atmospheric components and weather, as well as air pollutants. Specifically, moisture and particles of sea salt and sulfur dioxide are major factors in atmospheric corrosion. Using galvanized steel is one of the most efficient ways to protect iron from corrosion by zinc plating on the surface of the iron. Galvanized steel is widely used in automobiles, building structures, roofing, and other industrial structures due to their high corrosion resistance relative to iron. The atmospheric corrosion of galvanized steel shows complex corrosion behavior, depending on the plating, coating thickness, atmospheric environment, and air pollutants. In addition, corrosion products are produced in different types of environments. The lifespans of galvanized steels may vary depending on the use environment. Therefore, this study investigated the corrosion behavior of galvannealed steel under atmospheric corrosion in two locations in Korea, and the lifespan prediction of galvannealed steel in rural and coastal environments was conducted by means of the potentiostatic dissolution test and the chemical cyclic corrosion test.

• 환경생물
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• 제36권3호
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• pp.392-399
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• 2018

해산로티퍼(Brachionus plicatilis)의 생존 및 개체군 성장률(r)을 사용하여 Zinc undecylenate (ZU)에 대한 독성평가를 실시하였다. 24 h 동안 ZU에 노출된 B. plicatilis의 생존율은 실험 최고농도 $100mg\;L^{-1}$에서도 영향이 나타나지 않았으나, ZU에 72 h 노출된 개체군 성장률(r)은 농도 의존적으로 감소하는 경향을 나타내, $12.5mg\;L^{-1}$에서 유의적인 감소를 나타냈고 최고농도 $50.0mg\;L^{-1}$에서 개체군 성장률이 90% 이상 감소되었다. ZU에 노출된 B. plicatilis의 개체군 성장률의 반수영향농도($EC_{50}$)값은 $26.4mg\;L^{-1}$, 무영향농도(NOEC)는 $6.3mg\;L^{-1}$, 최소영향농도(LOEC)는 $12.5mg\;L^{-1}$로 나타났다. 자연생태계 내에서 ZU 물질이 해수 중에서 $12.5mg\;L^{-1}$ 이상을 초과하여 나타낼 때 B. plicatilis와 같은 동물성플랑크톤의 개체군 성장률이 영향을 받을 것으로 판단되며, 이러한 연구결과는 신방오도료물질의 생태안정성 평가를 위한 기준치 설정 및 다른 방오도료물질과의 독성치를 비교할 수 있는 유용한 자료로 활용될 것으로 판단된다.

• 환경생물
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• 제37권3호
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• pp.372-379
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• 2019

해산규조류(Skeletonema cosatatum)의 개체군성장률(r)을 사용하여 연안 유기오염물질인 phenanthrene (PHE)과 zinc undecylenate (ZU)의 독성평가를 실시하였다. S. costatum을 PHE(0, 25, 50, 100, 200, 300 mg L^-1)와 ZU(0, 5, 10, 15, 20, 25 mg L^-1)에 각각 96시간 노출한 이후에 r을 산출하였고, 대조구의 r은 0.04보다 높아 시험기준에 적합하였다. S. costatum의 r은 PHE 50, ZU 10mg L^-1 이상의 농도에서 대조구 대비 유의하게 감소하기 시작해 PHE와 ZU의 농도가 증가할수록 감소되는 농도의존성을 나타냈으며, 최고농도인 300과 25mg L^-1 농도에서는 r이 나타나지 않았다. PHE와 ZU에 노출된 S. costatum r의 반수영향농도(EC₅₀)은 136.13, 16.95 mg L^-1, 무영향농도(NOEC)는 25, 5 mg L^-1, 최소영향농도(LOEC)는 50, 10 mg L^-1로 나타났다. 본 연구결과, 해양생태계 내에서 S. costatum의 r은 PHE 50 mg ^-1, ZU 10 mg L^-1 이상의 농도에서 독성영향으로 감소할 것으로 판단되며, PHE와 ZU의 기준농도 설정을 위한 기초자료로 유용하게 사용될 것이다.

• Journal of Preventive Medicine and Public Health
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• 제56권5호
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• pp.422-430
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• 2023

Objectives: Prolactin is vital for breastfeeding and milk production, and its secretion is influenced by factors related to the mother, infant, and environment. To date, no study has concurrently investigated the correlation of these factors with serum prolactin levels during lactation. Therefore, the objective of this study was to investigate the correlations among maternal and infant factors, lead exposure, and serum prolactin levels during lactation. Methods: A cross-sectional approach was employed in Surabaya, Indonesia, among 110 exclusively lactating mothers. The mothers' daily diets were determined using multiple 24-hour recalls, while blood lead levels were measured with inductively coupled plasma mass spectrometry. Serum prolactin levels were assessed using the electrochemiluminescence immunoassay. For bivariate analysis, we employed the Spearman correlation, Mann-Whitney, and Kruskal-Wallis tests, while for multivariate analysis, we utilized multiple linear regression. Results: The average serum prolactin level of the lactating mothers was 129.19±88.96 ng/mL. Positive correlations were found between serum prolactin levels and breastfeeding frequency (p<0.001), protein intake (p<0.001), and calcium intake (p=0.011) but had negative correlation with blood lead levels (p<0.001) and vitamin B6 intake (p=0.003). Additionally, prolactin levels were not significantly associated with maternal age; parity; intake of calories, vitamin D, vitamin E, zinc, folic acid, magnesium, or iron; infant age; or infant sex. Conclusions: Breastfeeding frequency had a stronger positive relationship with serum prolactin levels than protein and calcium intake. However, lead exposure was associated with reduced serum prolactin levels during lactation. Consequently, specific interventions from policymakers are necessary to manage breastfeeding in mothers exposed to lead.

• 대한소아치과학회지
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• 제34권2호
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• pp.322-328
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• 2007

제1대구치는 저작과 혼합치열기 이후의 수직적 교합관계형성에 핵심적인 역할을 하고 악골의 성장발육에 관여한다. 제1대구치의 매복은 하안면 고경의 감소, 낭의 형성, 치관 주위염, 인접치의 치근 흡수, 부정 교합 등의 문제점을 야기할 수 있다. 치료방법으로는 주기적 관찰, 외과적 노출술, 교정적 견인, 외과적 재위치술, 발치 등이 있으며 이중 외과적 노출술이 가장 기본이 되는 술식이다. 외과적 노출술시에는 맹출로의 개방성을 유지하는 것이 중요하며 개방성을 유지시키기 위한 방법으로는 레진관의 접착, 산화 아연 유지놀 시멘트, 치주포대 등을 노출된 부위에 충전시키는 방법 등이 있다. 본 증례에서는 매복된 하악 제1대구치에서 장애물의 제거와 외과적 노출술을 시행한 결과 자발적인 맹출을 관찰할 수 있었다. 또한 surgical pack과 투명상유지장치를 사용하여 간편하고 효과적으로 맹출로의 개방성을 유지할 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제28권4호
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• pp.875-884
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• 1995

In order to investigate the level of lead exposure of workers in litharge making industry and to evaluate how lead exposure, personal habit such as smoking and drinking affect the prevalence of lead related symptoms and other study variables, we investigate 114 workers(24 office workers and 90 lead exposed workers) in a litharge making industry. Study variables chosen were blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), Hemoglobin(Hb), hematocrit (Hct), SGOT and SGPT symptom questionnaires which had 15 lead exposure related symptoms were provided to all workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The mean value of PbB, ZPP and SGOT in lead exposed group were higher than those of non-exposed group, and there were no differences of means in other study variables. 2. The smoking and drinking rate of study subjects were 65.8% and 71.0% as a whole. Smoking rates were lower in non-exposed group than exposed group, but drinking rate were not. 3. There were no differences of mean values of study variables between smoker and non-smoker in non-exposed and exposed group, but there was a difference of mean value of SGOT between drinker and lion-drinker in lead exposed group. 4. While the symptom prevalence of lead exposed group were higher in neuromuscular category than non-exposed group, those of non-exposed group were higher or same with exposed group in gastrointestinal and general symptom category. 5. The symptom prevalence of smoker were higher than non-smoker regardless of exposure. 6. The symptom prevalence of drinker were only higher in gastrointestinal symptom category than non-drinker. 7. In multiple stepwise regression analysis of lead related symptoms as dependent variable and blood lead, smoking habit, drinking habit and work duration as independent variables, drinking habit contributed to the gastrointestinal symptom category, whereas blood lead and smoking contributed to the neuromuscular symptom category. For the total symptoms work duration and smoking habit contributed significantly.

• Journal of Preventive Medicine and Public Health
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• 제30권4호
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• pp.741-751
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• 1997

Measurement of blood lead (PbB) and blood zinc protoporphyrin (ZPP) are most common biological indices to identify the individual at risk for excess or the health sequences by lead exposure. Because PbB is known most important and reliable index of lead exposure, PbB is often regarded as a gold standard to detect lead exposure. But in Korea PbB is a secondary test item of detailed health check-up with positive finding of screening test in most occasion. Our lead standard requires all lead workers to take annual heath-check twice a year for investigation of their health effect due to lead exposure. Blood ZPP is one of most important index to detect high lead absorption in lead workers as a screening test. Measurement of blood ZPP is known ,well to correlate with PbB in steady state of exposure in most lead workers and is often used as a primary screening test to detect high lead absorption of lead workers with the advantage of simplicity, easiness, portability and low cost. The current cut-off criteria of blood ZPP for further detailed health check-up is $100{\mu}g/d\ell$ which is supposed to match the level of $40{\mu}g/d\ell$ of PbB according to our standard. Authors tried to investigate the validity of current criteria of cut-off level $(100{\mu}g/d\ell)$ of blood ZPP and possible another better cut-off level of it to detect the lead workers whose PbB level over $40{\mu}g/d\ell$. The subjects in our study were 212 male workers in three small scale storage battery industries. Blood ZPP, PbB and hemoglobin (Hb) were selected as the indices of lead exposure. The results were as follows. 1. The mean of blood ZPP, PbB and Hb in lead workers were $79.5{\pm}46.7{\mu}g/d\ell,\;38.7{\pm}15.1{\mu}g/d\ell,\;and\;14.8{\pm}1.2g/d\ell$, respectively. There were significant differences in blood ZPP, PbB and Hb by industry (P<0.01). 2. The percents of lead workers whose blood ZPP were above $100{\mu}g/d\ell$ in the group of work duration below 1, 1-4, 5-9 and above 10 years were 8.6%, 17.2%, 47.6%, and 50.0%, respectively. The percents of lead workers whose PbB were above $40{\mu}g/d\ell$ in those were 31.4%, 40.4%, 71.4%, and 86.4%, respectively. 3. The percents of lead workers whose PbB were below $40{\mu}g/d\ell$, $40-59{\mu}g/d\ell$ and above $60{\mu}g/d\ell$ were 54.7%, 34.9% and 10.4%, respectively. Those of lead workers whose blood ZPP were below $100{\mu}g/d\ell$, $100-149{\mu}g/d\ell$ and above $150{\mu}g/d\ell$ were 79.2%, 13.7% and 7.1%, respectively. 4. Simple linear regression of PbB on blood ZPP was statistically significant (P<0.01) and as PbB was $40{\mu}g/d\ell$, blood ZPP was $82.1{\mu}g/d\ell$. 5. While the highest sensitivity and specificity of blood ZPP test to detect lead workers with PbB eve. $40{\mu}g/d\ell$ were observed in the cut-off level of $50{\mu}g/d\ell$ and $100{\mu}g/d\ell$ of blood ZPP, respectively, the highest validity (sensitivity+specificity) of blood ZPP to detect lead workers with PbB over $40{\mu}g/d\ell$ was observed in the cut-off level of around $70{\mu}g/d\ell$ of blood ZPP. But even with optimal cut-off level of around $70{\mu}g/d\ell$ of blood ZPP, still 25.0% of false negative and 20.7% false positive lead workers were found. As the result of this study, it was suggested that reconsideration of current blood ZPP cut-off of our lead standard from $100{\mu}g/d\ell$ to somewhat lower level such as around $70{\mu}g/d\ell$ and the inclusion of PbB measurement as a primary screening test for lead workers was highly recommended for the effective prevention of lead workers.

• Journal of Preventive Medicine and Public Health
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• 제32권4호
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• pp.499-504
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• 1999

Objectives : To evaluate whether a relation between blood lead and zinc proto porphyrin(ZPP) was modified by gender in Korean lead workers. Methods : A cross-sectional study was conducted with 1,304 male and 101 female subjects in 1997. The relation between blood lead and ZPP were evaluated with linear, exponential, and quadratic models. Then, the different effect of gender on the relation was examined by adding the interaction terms in the each model. Results : $Mean{\pm}SD$ of blood lead and ZPP level was different between male$(27.7{\pm}10{\mu}g/dl\;and\;51.3{\pm}23.4{\mu}g/dl)$ and female subjects$(22.5{\pm}9.2{\mu}g/dl\;and\;78.7{\pm}38.6{\mu}g/dl)$. After adjusting for possible confounders, the effect modification by gender was significant in linear$(\beta=1.119,\;p<0.001)$, exponential$(\beta=Exp(0.008),\;p<0.05)$, and quadratic model$(\beta=1.388,\;p<0.001)$. In separate analysis, a quadratic relation between blood lead and ZPP was shown in male lead workers$(\beta=0.036,\;p<0.001)$, but an exponential relation in female lead workers$(\beta=Exp(0.029), p<0.001)$. Conclusion : Our data showed that the increasing rate of ZPP in female were always higher than in male lead workers, suggesting that females were more susceptible to occupational lead exposure than males.