• Journal of Preventive Medicine and Public Health
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• 제43권4호
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• pp.301-308
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• 2010

Objectives: In most DEHP exposure assessment studies, single spot urine sample was used. It could not compare the exposure level among studies. Therefore, we are going to represent the necessity of selection of proper sampling time of spot urine for assessing the environmental DEHP exposure, and the association urinary DEHP metabolites with steroid hormones. Methods: We collected urine and plasma from 25 men. The urine sampling times were at the end of the shift (post-shift) and the next morning before the beginning of the shift (pre-shift). Three metabolites of DEHP {mono(2-ethylhexyl) phthalate [MEHP], mono-(2-ethyl-5-hydroxyhexyl)phthalate [MEHHP], and mono(2-ethyl-5-oxohexyl)phthalate [MEOHP]} in urine were analyzed by HPLC/MS/MS. Plasma luteinzing hormone, follicle stimulating hormone, testosterone, and $17{\beta}$- estradiol were measured at pre-shift using a ELISA kit. A log-transformed creatinine-adjusted urinary MEHP, MEHHP, and MEOHP concentration were compared between the post- and pre-shift. The Pearson’s correlation was calculated to assess the relationships between log-transformed urinary MEHP concentrations in pre-shift urine and hormone levels. Results: The three urinary metabolite concentrations at post-shift were significantly higher than the concentrations in the pre-shift (p<0.0001). The plasma hormones were not significantly correlated with log-transformed creatinine - adjusted DEHP metabolites. Conclusions: To assess the environmental DEHP exposure, it is necessary to select the urine sampling time according to the study object. There were no correlation between the concentration of urinary DEHP metabolites and serum hormone levels.

• 한국발생생물학회지:발생과생식
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• 제24권2호
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• pp.71-78
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• 2020

Endometriosis is a common gynecologic disease, worldwide, whose true prevalence is uncertain because it is a difficult disease to diagnose. Endometriosis is a common cause of chronic pelvic pain, dysmenorrhea, and infertility, and is also associated with ovarian cancer. Although the risk factors for endometriosis are unclear, there is increasing evidence that exposure to environmental contaminants, especially phthalates, could affect the pathogenesis of endometriosis. Phthalates are industrial chemicals, used to make flexible plastics, and are present in numerous common plastic products, including medical devices and materials. Several in vitro studies have suggested a positive association between exposure to phthalate, or phthalate metabolites, and the risk of endometriosis. Since the 2000s, studies based on human plasma and urinary concentrations of various phthalate metabolites have been published, but there are still limitations to our understanding of the pathophysiology of phthalates and endometriosis. This report aims to review the current state of knowledge about a possible role of phthalates in the pathogenesis of endometriosis based on cell culture, animal models, and human data.

• 실내환경 및 냄새 학회지
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• 제17권4호
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• pp.315-321
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• 2018

Phthalate is an endocrine disruptor that interferes with homeostasis and developmental regulation. It is highly toxic to the environment and is associated with various diseases of the human body. Using biological samples from 140 adult subjects, to evaluate the influencing factors which are related to contaminant concentration levels, we used correlation analysis and multiple regression analysis. Lastly, in order to analyze the health effects related to exposure to phthalates, we conducted a risk assessment by estimating acceptable daily intake exposure according to the influential factors. When we compared the concentration level according to influential factors, in general, the subjects who had engaged in home remodeling work had higher urinary phthalate metabolite concentrations levels than the subjects who had not engaged in home remodeling work. We can confirm statistically significant differences in DBP metabolites. In addition, we can confirm the concentration appeared higher in the categories such as using air freshener, sofa and foods. Through conducting a risk assessment of DEHP, BBzP, DiBP, and DnBP by using data on phthalate metabolite concentration in urine, it was found that the average concentration of all metabolites did not exceed TDI.

• 한국환경보건학회지
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• 제44권6호
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• pp.572-580
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• 2018

Objectives: Human biomonitoring (HBM) is a measurement of the chemicals and their metabolites in human biological samples and has been successfully employed to determine the exposure levels of environmental chemicals. In this study, we analyzed seasonal variations of the blood or urinary levels of chemicals, and assessed that these differences could affect the results of association study. Methods: The Korea National Environmental Health Survey (KoNEHS) is a nationwide survey that analyzes exposure levels of environmental pollutants, 19 kinds of chemicals including heavy metals and organic chemicals, and the exposure factors in the general population. Based on KoNEHS data, we analyzed the levels of chemicals concentrations over the total survey period (2012-2014) and each season, and assessed the association of thyroid measures with phthalate metabolite and BPA. Results: Exposure levels of blood mercury and lead were lower in summer compare to winter. Bisphenol A and PAHs metabolites were higher in spring and summer, but lower in autumn. VOCs metabolites were generally lower in summer and autumn. Phthalate metabolites were higher in all other seasons than in winter. Pyrethroid metabolite, 3-PBA, was higher in summer and autumn. Regarding seasonal variation of chemical exposures, the statistical significance and size of effects between thyroid measures and phthalate and BPA were changed with season. Conclusion: Seasonal variations of chemical exposure and health outcome should be considered for interpreting biomonitoring results from a public health context.

• 한국발생생물학회지:발생과생식
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• 제24권1호
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• pp.1-17
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• 2020

Phthalates and those metabolites have long history in industry and suspected to have deficient effects in development and reproduction. These are well-known anti-androgenic chemicals and many studies have examined the effects of these compounds on male reproduction as toxins and endocrine disruptors. Uterus is a key organ for proper embryo development, successful reproduction, and health of eutherian mammals including women. To understand the effects of the phthalate, the horizontal approach with a whole group of phthalate is best but the known phthalates are huge and all is not uncovered. Di-(2-ethylhexyl) phthalate (DEHP) is the most common product of plasticizers in polymer products and studied many groups. Although, there is limited studies on the effects of phthalates on the female, a few studies have proved the endocrine disrupting characters of DEHP or phthalate mixture in female. An acute and high dose of DEHP has adverse effects on uterine histological characters. Recently, it has been revealed that a chronical low-dose exposing of DEHP works as endocrine disrupting chemicals (EDC). DEHP can induce various cellular responses including the expression regulation of steroid hormone receptors, transcription factors, and paracrine factors. Interestingly, the response of uterus to DEHP is not monotonous and the exposed female has various phenotypes in fertility. These suggest that the exposing of DEHP may causes of histological modification in uterus and of disease in female such as endometriosis, hyperplasia, and myoma in addition to developmental and reproductive toxicity.

• Journal of Microbiology and Biotechnology
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• 제10권4호
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• pp.518-521
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• 2000

Aspergillus niger is capable of metabolizing dimethyphthalate. The maximum weight of mycelium wa observed afterabout 6-8 dys of incubation. A TLC analysis revealed the accumulation of metabolites in the resting cell culture. Monomethylphthalate, phthalate, and protocatechuate were shown to be the intermediates by thin layer chromatographic and spectrophotometric analyses. The fungus metabolized dimethylphthalate through monomethylphthalate, phthalate, and protocatechuate as evidenced by the oxygen uptake and an enzymatic analysis. The terminal aromatic metabolite, protocatechuate, is metabolized via the ortho-cleavage pathway.

• 한국환경보건학회지
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• 제46권5호
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• pp.548-554
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• 2020

Objectives: This study is to examine the polyvinyl chloride (PVC) materials in elementary school classrooms and libraries in Seoul, and to investigate phthalate contamination in indoor dust. Methods: PVC material was identified for building materials and furniture using portable x-ray fluorescence (XRF). Phthalates in dust samples (n=19) were extracted by ultrasonic extraction using cyclohexane and analyzed by GC-MS. Results: Diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and Bis (2-ethylhexyl) phthalate (DEHP) were found in all collected dust samples (n=19), and diisonyl phthalate (DINP) was detected in all except for one sample (n=18). The concentration of DEHP (median: 2190 mg/kg) and DINP (2960 mg/kg) were higher than other compounds, suggesting that there are many products in the school that used these compounds. When comparing the phthalate concentration in the classroom (n=11) and library dust (n=8), the total concentration in the classroom (median: 10000 mg/kg) was higher than that in the library (8030 mg/kg). DEHP was the dominant compound in the library. The library is relatively more equipped with PVC furniture (n=83) and most floors are also identified as PVC material, suggesting that floors and furniture made of PVC materials are main sources of DEHP contamination. Conclusions: This study is a pilot survey for investigating phthalate contamination in elementary schools. As a result of the survey, phthalate contamination in elementary school was confirmed. However, further study requires risk assessment of children through analysis of phthalate metabolites in children based on sufficient number of samples and information about the site.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1440-1445
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• 2010

Rhodococcus sp. JDC-11, capable of utilizing di-n-butyl phthalate (DBP) as the sole source of carbon and energy, was isolated from sewage sludge and confirmed mainly based on 16S rRNA gene sequence analysis. The optimum pH, temperature, and agitation rate for DBP degradation by Rhodococcus sp. JDC-11 were 8.0, $30^{\circ}C$, and 175 rpm, respectively. In addition, low concentrations of glucose were found to inhibit the degradation of DBP, whereas high concentrations of glucose increased its degradation. Meanwhile, a substrate utilization test showed that JDC-11 was also able to utilize other phthalates. The major metabolites of DBP degradation were identified as monobutyl phthalate and phthalic acid by gas chromatography-mass spectrometry, allowing speculation on the tentative metabolic pathway of DBP degradation by Rhodococcus sp. JDC-11. Using a set of new degenerate primers, a partial sequence of the 3,4-phthalate dioxygenase gene was obtained from JDC-11. Moreover, a sequence analysis revealed that the phthalate dioxygenase gene of JDC-11 was highly homologous to the large subunit of the phthalate dioxygenase from Rhodococcus coprophilus strain G9.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.176-186
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• 2022

Continued fenvalerate use has caused serious environmental pollution and requires large-scale remediation. Dibutyl phthalate (DBP) was discovered in fenvalerate metabolites degraded by Citrobacter freundii CD-9. Coculturing is an effective method for bioremediation, but few studies have analyzed the degradation pathways and potential mechanisms of cocultures. Here, a DBP-degrading strain (BDBP 071) was isolated from soil contaminated with pyrethroid pesticides (PPs) and identified as Stenotrophomonas acidaminiphila. The optimum conditions for DBP degradation were determined by response surface methodology (RSM) analysis to be 30.9 mg/l DBP concentration, pH 7.5, at a culture temperature of 37.2℃. Under the optimized conditions, approximately 88% of DBP was degraded within 48 h and five metabolites were detected. Coculturing C. freundii CD-9 and S. acidaminiphila BDBP 071 promoted fenvalerate degradation. When CD-9 was cultured for 16 h before adding BDBP 071, the strain inoculation ratio was 5:5 (v/v), fenvalerate concentration was 75.0 mg/l, fenvalerate was degraded to 84.37 ± 1.25%, and DBP level was reduced by 5.21 mg/l. In addition, 12 fenvalerate metabolites were identified and a pathway for fenvalerate degradation by the cocultured strains was proposed. These results provide theoretical data for further exploration of the mechanisms used by this coculture system to degrade fenvalerate and DBP, and also offer a promising method for effective bioremediation of PPs and their related metabolites in polluted environments.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.946-951
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• 2005

Biodegradation of the endocrine-disrupting chemical di-n-butyl phthalate (DBP) was investigated using a bacterium, Pseudomonas fluorescens B-1, isolated from mangrove sediment. The effects of temperature, pH, salinity, and oxygen availability on DBP degradation were studied. Degradation of DBP was monitored by solid-phase extraction using reversed-phase HPLC and UV detection. The major metabolites of DBP degradation were identified as mono-n-butyl phthalate and phthalic acid by gas chromatography-mass spectrometry (GC-MS) and a pathway of degradation was proposed. Degradation by P. fluorescens B-1 conformed to first-order kinetics. Degradation of DBP was also tested in seawater by inoculating P. fluorescens B-1, and complete degradation of an initial concentration of $100{\mu}g/l$ was achieved in 144 h. These results suggest that DBP is readily degraded by bacteria in natural environments.