• Toxicological Research
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• v.16 no.1
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• pp.27-31
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. EPA and OECD are developing screening programs using validated test systems to determine whether certain substances may have an effect on humans. In the present study, the establishment of in vivo short-term test system for pubertal female assay with thyroid to detect endocrine disrupting chemicals was tried using a model substance, methoxychlor (MC), a chlorinated hydrocarbon insencticide. Forty female rats were assigned to four groups. MC was administered at dose levels of 0, 8, 40 and 200mg/kg by gavage to female rats from day 21 post partum to the completion of vaginal opening. We evaluated body weight change, age at vaginal opening, onset of estrous cyclicity, age at first esturs, ovary weight, and serum concentrations of thyroxine and thyroid stimulating hormone in female rats. The age at vaginal opening of females receiving 40 200mg/kg was significantly younger than control. The onset of estrus cyclicity and age at first estrus of females receiving 200mg/kg was also younger than controls. There was no effect of treatment on body weight, ovary weight, and hormone concentration. Based on these results, it can be concluded that application of MC at dose level of 40mg/kg affects the vaginal opening and application of MC at dose level of 200mg/kg accelerates the vaginal opening and the onset of estrus cylicity.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.195-195
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• 2003

It is well known that diesel exhaust particulate matter contains mutagenic PAHs, such as benzo[${\alpha}$]pyrene, benz[${\alpha}$]anthracene, chrysene, etc. Therefore it is suspected that these chemicals act on estrogen receptor and reveal endocrine-disrupting effects. Recent attention has focused on causative chemicals of endocrine-disrupting effects. We examined the estrogenic activity of respirable diesel exhaust particulate matter derived from diesel powered vehicle. PM2.5 diesel exhaust of vehicle was collected using a high volume sampler equipped with a cascade impactor. Diesel exhaust samples were fractionated according to EPA methods. The presence of estrogenic and antiestrogenic chemicals in PM 2.5 diesel exhaust was determined using E-screen assay. To quantitatively assess the estrogenic and antiestrogenic activities in diesel exhaust particulate matter, estradiol equivalent concentration (bio-EEQ) was calculated by comparing the concentration response curve of the sample with those of the estrogen calibration curve. Weak estrogenic activities and strong antiestrogenic activities were detected in the crude extract and moderately polar fractions. Higher antiestrogenic potency was observed with higher EROD activities in aliphatic and aromatic compounds fraction. In conclusion, estrogenic/antiestrogenic-like activities were present in diesel exhaust particulate matter. However, the health consequences of this observation was unknown, the presence of these activities may contribute to and exacerbate adverse health effect evoked by diesel exhaust particulate matter.

• Journal of the Korean Dietetic Association
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• v.26 no.3
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• pp.183-195
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• 2020

Endocrine-disrupting chemicals (EDCs) are chemicals present in the environment that interfere with the normal hormone functions of various organisms and cause genetopathy, deformities, or cancer. This study surveyed the awareness of EDCs with 242 cooking staff at 242 meal service facilities for children located in a part of Gyeonggi Province. To minimize infants' exposure to EDCs, the subjects were provided with information on EDCs for two months. The behavior of reducing exposure to EDCs was analyzed according to the awareness of EDCs and work ethics. In addition, the effects before and after being provided with the information were evaluated. According to the results, the levels of awareness of EDCs and work ethics' scores of the cooking staff were high with 3.95 and 4.39 points, respectively, out of five points. In addition, a higher awareness of EDCs and a higher work ethics' score were associated with an improved behavior of reducing exposure to EDCs (P<0.05). The overall cooking and cleaning behavior for reducing exposure to EDCs showed improvement after providing information (P<0.01). Therefore, these results suggest that it is important to provide continuous education to enhance the awareness of EDCs, work ethics, and behavior to reduce exposure to EDCs.

• Environmental Mutagens and Carcinogens
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• v.23 no.2
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• pp.51-55
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• 2003

Benzo(a)pyrene and bisphenol A have been classified as endocrine disrupting chemicals (EDCs), which have been of concern in toxicology and environmental sciences. Benzo(a)pyrene and bisphenol A were monitored by HPLC or GC-MS in Baekwoon and Ilwirl lakes of Kyonggi-Do province to investigate contamination levels of EDCs. During the period between June, 2000 and August, 2000, water samples were collected from four different sites of each lake once per month. Contamination levels of benzo(a)pyrene were 3.27~4.25 ppb in Ilwirl lake and 2.00~2.33 ppb in Baekwoon lake, respectively. Bisphenol A levels were detected with the range of 0.33~7.94 and 0.43~4.71 for Baekwoon lake and Ilwirl lake, respectively. pH levels were higher in Ilwirl lake than in Baekwoon lake, where the contamination was relatively lower. These data suggest that lakes in Kyonggi-Do province could be contaminated with EDCs and be subjected to the routine monitoring and water quality control.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.145-145
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• 2003

A method for the determination of alkylphenols, chlorophenols and bisphenol A in paper materials using GC/MS-SIM has been developed. Eleven endocrine disrupting chemicals (EDCs) of phenols in paper samples were extracted with acetonitrile. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 82.4∼108.8 % by area ratio of pheranthrene-d$\sub$10/ vs bisphenol A d$\sub$l6/. (isoBOC derivatization and TBDMS derivatization) The SIM responses were linear with the correlation coefficient varying 0.9717∼0.9995 (isoBOC derivatization), and 0.9842∼0.9980 (TBDMS derivatization). The range of concentrations was respectively, 0.95∼l.44 ng/g in 2,4-dichlorophenol, 1.01∼1.17 ng/g in t-butylphenol, 2.17∼5.84 ng/g in pentachlorophenol, 12.68∼14.88 ng/g in nonylphenol and 30.84∼153.72 ng/g in bisphenol A.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.659-664
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• 2007

The objective of this study is to evaluate the detoxification method for the endocrine disrupting chemicals by manganese oxide. Manganese coated sand and bisphenol-A (BPA) was used as the reactive medium and the contaminant. Results showed that manganese oxide effectively degrades BPA by oxidative coupling reaction. The nonlinear oxidative coupling reaction orders were obtained for BPA and oxide, respectively. The reaction rate of BPA decreased as initial BPA concentration increased, as oxide loading decreased and as pH increased. The higher ionic strength, the higher reaction rate was observed. Divalent cations were adsorbed on the oxide surfaces, resulting in the decreased degradation rate of BPA.

• Clinical and Experimental Pediatrics
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• v.49 no.7
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• pp.718-725
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• 2006

The pubertal activation of gonadotrophin releasing hormone(GnRH) requires coordinated changes in excitatory or inhibitory amino acids, growth factors, and a group of transcriptional regulators. The age of onset of puberty is progressing to younger age. Factors affecting early puberty include genetic traits, nutrition(body fat) and exposure to endocrine disrupting chemicals. In rapidly progressing central precocious puberty, gonadotrophin releasing hormone(GnRH) agonists(GnRHa) appear to increase final height if treated early stage. Further large scaled long-term follow-up study of the effects of GnRHa on final height is needed.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.99-104
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• 2003

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2004.05a
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• pp.61-65
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• 2004

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2004.05a
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• pp.73-73
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• 2004