• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.948-953
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• 2010

In this study, degradation of estrone (E1) and $17{\alpha}$-ethynylestradiol (EE2) by gamma-irradiation and subsequent reduction of estrogenic activity as a function of absorbed dose were conducted using the yeast two-hybrid assay. Relative potency of E1 and EE2 compared to estrogenic activity of $17{\beta}$-estradiol (E2) was found to be 0.0144 and 0.1605, respectively. More than 90% of E1 and EE2 (both $5.0{\times}10^{-6}M$) was removed at an absorbed dose of 5 kGy, but more than 40% of estrogenic activity still remained. The addition of $TiO_2$ catalyst appeared to improve the removal efficiency of E1 and decrease estrogenic activity while there was no significant effect for EE2. Additionally, the calculated estrogenic activity of E1 and EE2 based on a regression model was well correlated with the observed activity.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1463-1471
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• 2015

The surface modified activated carbons (SMACs) were prepared with various $P_2O_5$ concentrations using two activated carbons (ACs: waste citrus peel-based activated carbon and coconut-based activated carbon). The characteristics and adsorptivity of bisphenol A (one of phenolic endocrine disrupting chemicals) were compared between ACs and SMACs. The contents of C, H and N of SMACs were similar to those of ACs, but the content of $P_2O_5$ for the former increased greatly than for the latter, due to the impregnation of $P_2O_5$ into the pores. The specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former decreased due to the impregnation of $P_2O_5$ into the pores, compared to those for the latter. The adsorptivity of bisphenol A for the former were higher than that for the latter, although specific surface area, total pore volume, average pore diameter and iodine adsorptivity for the former were lower than those for the latter.

• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.287-294
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• 2010

Objectives : The aim of this study was to verify the intersexuality of Crassostrea gigas and Ruditapes philippinarum in southern coastal waters of Korea. Methods : Specimens of Crassostrea gigas (n=363) were collected from six areas of Tongyeong, Geoje and Yeosu. Ruditapes philippinarum (n=221) was collected from five areas of Yeosu. The sex ratio and intersexuality were determined after observing gonad preparations. Results : The rate of intersexuality in Crassostrea gigas was 16.25%, with females (24.79%; n=30/121) exhibiting a higher rate than males (11.98%; n=29/242). The rate of intersexuality in Ruditapes philippinarum was 24.43%, with females (37.76%; n=37/98) exhibiting a higher rate than males (13.82%; n=17/123). Conclusions : The results of this study suggest that intersexuality is induced by aquatic pollutants such as endocrine disrupting chemicals (EDCs).

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.412-421
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• 2017

Objectives: To establish a system for integrated risk assessment of EDCs in Korea, infrastructure for providing toxicity data of ecological media should be established. Some systems provide soil ecotoxicity databases along with aquatic ecotoxicity information, but a well-structured ecotoxicity database system is still lacking. Methods: Aquatic and soil ecotoxicological information were collected by a toxicologist based on a human readable data (HRD) format for collecting ecotoxicity data that we provided. Among these data, anomalies were removed according to database normalization theory. Also, the data were cleaned and encoded to establish a machine-readable data (MRD) ecotoxicity database system. Results: We have developed a multi-purpose ecotoxicity database model focusing on EDCs, ecological species, and toxic effects. Also, we have constructed a web-based data searching system to retrieve, extract, and download data with greater availability. Conclusions: The results of our study will contribute to decision-making as a tool for efficient ecological risk assessment of EDCs in Korea.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.279-284
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• 2006

Activated carbon is proposed as a new application of wastepaper recycling other than the paper-making. Waste kraft bag is considered to be a suitable raw material for activated carbon because of its low ash content. Small pellets of wastepaper squeezed out from the continuous kneader were carbonized in a nitrogen atmosphere and activated using carbon dioxide. The BET specific surface areas of activated carbon prepared from waste kraft bag was $1,285m^{2}/g$, which is higher than commercially available activated carbons. The activated carbon prepared from wastepaper has a well-developed porous structure, particularly in mesopore and macropore ranges. As a result, activated carbon with iodine adsorption capacity of 1,400 mg/g was obtained from waste kraft bag. In this paper, adsorption amount of Bisphenol A (BPA) was determined to investigate adsorbability of activated carbon from waste kraft bag. Adsorption measurements were on solutions ranging from $0.1{mu}g/L\;to\;100mg/L$. The activated carbon from waste kraft bag gave higher BPA adsorbabilities over a wide range, compared with commercially available activated carbons.

• Current Optics and Photonics
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• v.1 no.1
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• pp.12-16
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• 2017

Color sensor systems based on M13 bacteriophage are being considerably researched. Although many studies on M13 bacteriophage-based chemical sensing of TNT, endocrine disrupting chemicals, and antibiotics have been undertaken, the fundamental physical and chemical properties of M13 bacteriophage-based nanostructures require further research. A simple M13 bacteriophage-based colorimetric sensor was fabricated by a simple pulling technique, and M13 bacteriophage was genetically engineered using a phage display technique to exhibit a negatively charged surface. Arrays of structurally and genetically modified M13 bacteriophage that can determine the polarity indexes of various alcohols were found. In this research, an M13 bacteriophage-based color sensor was used to detect various types of alcohols, including methanol, ethanol, and methanol/butanol mixtures, in order to investigate the polarity-related property of the sensor. Studies of the fundamental chemical sensing properties of M13 bacteriophage-based nanostructures should result in wider applications of M13 bacteriophage-based colorimetric sensors.

• Women's Health Nursing
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• v.24 no.4
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• pp.392-403
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• 2018

Purpose: To identify factors associated with menstrual distress and characterize the relationship between menstrual distress and sleep disturbance in middle-school girls. Methods: Participants in this correlational study were 117 middle-school girls who were recruited through convenience sampling. Data were collected from March 2018 to April 2018 using self-reported structured questionnaires and analyzed using IBM SPSS Statistics 23.0. Factors associated with menstrual distress included physiological, psychological, and situational factors based on the theory of unpleasant symptoms. Results: Age of menarche (${\beta}=-.28$, p<.001), amount of menstruation (${\beta}=.23$, p=.004), lifestyle-related exposure to endocrine-disrupting chemicals (${\beta}=.21$, p=.027), and academic and peer-relationship stress (${\beta}=.19$, p=.025) influenced menstrual distress, explaining 47.4% of the variance in this regression model. The relationship between menstrual distress and sleep disturbance was statistically significant. Sleep disturbance was increased 1.26 folds when dysmenorrhea score increased by one unit (OR=1.26, 95% CI: 1.01~1.58). However, parental support was not a significant moderating factor of sleep disturbance. Conclusion: This study provides basis to develop an intervention strategy to alleviate menstrual discomfort in adolescents and improve their quality of sleep.

• Development and Reproduction
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• v.26 no.4
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• pp.175-182
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• 2022

Previous studies, including our own, indicate that distinct morphological changes in rodent adrenal cortex could be induced by exposure of endocrine disrupting chemicals (EDC). In the present study, we conducted histological analyses of adrenocortical substructure using a nonylphenol-treated F1 rat model. The adrenal weight of NP-5000 group was significantly declined in female rats (p<0.001), while the adrenal weights of NP-treated groups were not significantly changed in male rats. The thickness of zona glomerulosa layers of female rats in NP-5000 group was significantly declined (p<0.001) but zona fasciculata layers were not changed. The zona reticularis layers of NP-treated group were significantly thinner than those of control group (NP-50, p<0.05; NP-5000, p<0.01). In male adrenal glands, there was no significant change of zona glomerulosa layers in NP-treated groups while the thickness of zona fasciculata in NP-5000 group was significantly decreased (p<0.01). Like female rats, the thickness of zona reticularis in NP-treated groups was significantly decreased (NP-50, p<0.001; NP-5000, p<0.05). Present study demonstrated that the adrenal histology could be altered by low-dose NP exposure in F1 rats, and the effect might be sexually dimorphic. Further study will be helpful for understanding possible adrenal pathophysiology induced by EDC exposure, and EDC-related sexually dimorphic phenomena in rodent adrenals.

• Analytical Science and Technology
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• v.37 no.5
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• pp.271-279
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• 2024

Bisphenols and phthalates are endocrine-disrupting chemicals that are commonly used in packaging and as plasticizers. However, they pose health risks through ingestion, inhalation, and dermal contact. Accurate analysis of these pollutants is challenging owing to their low concentration and their presence in complex oil matrices. Therefore, they require efficient extraction and detection methods. In this study, an analytical method for the simultaneous quantification of bisphenols and phthalates in corn oil is developed. The dynamic multiple reaction monitoring mode of liquid chromatography-tandem mass spectrometry is used according to the different polarities of bisphenols and phthalates. The method is validated by assessing system suitability, linearity, accuracy, precision, homogeneity, and stability. The determination coefficients are higher than 0.99, which is acceptable. The percentage recovery and coefficient of variation of the accuracy and precision confirm that this analytical method is capable of simultaneously quantifying bisphenols and phthalates in corn oil. The bisphenols and phthalates in the formulations and pretreatment samples are stable for 7 d at room temperature and 24 h in an auto-sampler. Therefore, this validated analytical method is effective for the simultaneous quantification of bisphenols and phthalates in oils.

• Analytical Science and Technology
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• v.18 no.2
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• pp.147-153
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• 2005

Benzophenone (BP) which is one of endocrine disrupting chemicals is suspected to contaminate waters (river, lake and industrial drainage) and soils (ground soil and sediment). Analytical method for determination of BP in soil and water was developed by gas chromatography/mass spectrometry. Water sample (100 mL) was extracted with n-hexane, and soil (10 g) was extracted with methanol and n-hexane. Recovery for BP was >71.4% in water and 86.5-94.7% in soil with coefficient variation of less than 19.8%. Calibration curves showed a good linearity ($r^2$ >0.998). In water, soil and sediment collected at nation-wide sites, BP was detected at 5 sites among 43 water sites at the concentration range of 30-200 ng/L. No BP was found in the soil and sediment samples. It is suggested that this method will be useful to the determination of BP in the environmental matrices such as waters, soils and sediments in minute quantities.