Un-jung Kim

Un-jung Kim
University of Texas at Arlington | UTA · Department of Earth and Environmental Sciences

PhD

About

47
Publications
6,195
Reads
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1,257
Citations
Introduction
My work centers on environmental chemicals and persistent toxic substances. Major interests are in the development of sampling/analytical methods, monitoring of priority contaminants in human, wildlife, environment, consumer products and delineating exposure sources, pathways and impact of chemicals on receptors. We’re conducting both field and laboratory experiments and strongly rooted in GC/LC mass spectrometry and relevant environmental analytical chemistry and engineering techniques.
Additional affiliations
January 2020 - present
University of Texas at Arlington
Position
  • Professor (Assistant)
February 2018 - December 2018
Korea Institute of Toxicology
Position
  • Researcher
March 2016 - February 2018
Wadsworth Center, NYS Department of Health
Position
  • PostDoc Position
Education
March 2011 - August 2014
Pusan National University
Field of study
  • Civil and Environmental Engineering
September 2009 - February 2011
Pusan National University
Field of study
  • Civil and Environmental Engineering
March 2005 - August 2009
Pusan National University
Field of study
  • Applied Chemical Engineering & Urban Engineering

Publications

Publications (47)
Article
The concentrations, congener profiles, and phase-specific distribution profiles of 27 polybrominated diphenyl ethers and 10 hydroxylated and 18 methoxylated brominated diphenyl ethers (OH- and MeO-BDEs; later called structural analogs of PBDEs) were determined in surface soil, water, air, and vegetation from the south-eastern city of Busan, Korea f...
Article
Polybrominated diphenyl ethers (PBDEs) are group of chemicals which are representative persistent organic pollutants (POPs) and used as brominated flame retardants for many consumer products. PBDEs were phased out since 2009 but are still frequently observed in various environmental matrices and human body. Here, we report ssDNA aptamers which bind...
Article
Full-text available
Prior research suggests that severe iodine deficiency in pregnancy may be associated with stillbirth. However, the relationship between mild to moderate iodine insufficiency, which is prevalent even in developed countries, and risk of stillbirth is unclear. We thus examined associations of iodine status and risk of stillbirth in a prospective popul...
Article
Full-text available
Preeclampsia, a pregnancy disorder that includes hypertension and proteinuria, is a major cause of maternal and fetal morbidity and mortality. Some studies, but not all, have found that women with preeclampsia have significantly lower iodine levels than healthy pregnant women. Resolving this issue is important because iodine deficiency in pregnancy...
Article
Sample preparation is one of the crucial steps in the analytical chemistry including human biomonitoring studies. Although, there are several traditional approaches available, solid-phase microextraction is emerged as one of the pioneering techniques due to its simplicity, rapidness, wide applicability, and miniaturization of traditional sample pre...
Article
Full-text available
Perchlorate (ClO4−) has been identified as a persistent environmental contaminant of concern. Perchlorate exposure is a potential health concern because it interferes with hormone production by thyroid gland. Food (fruits and vegetables) and drinking water are an important source of human exposure to perchlorate. However, little is known about the...
Article
We conducted a probabilistic risk assessment for seven nitrosamines (i.e., N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosodibuthylmine (NDBA), N-nitrosopyrrolidine (NPYR), N-nitrosopiperidine (NPIP), N-nitrosomorpholone (NMOR) and N-nitrosomethylethylamine (NMEA)) to assess the cancer risk posed by dietary intake of nitrosami...
Article
Perchlorate occurs naturally in the environment in deposits of nitrate and can be formed in the atmosphere and precipitate into soil. However, little is known about the occurrence and levels of perchlorate in soils and fertilizers in Chile and its impacts on agricultural systems and food safety. In this study, concentrations of perchlorate were det...
Chapter
PDF version of the chapter can be downloaded by the link below which valid through April 03, 2020. The link is provided from Elsevier to the author for the purpose of posting the link into personal website and/or social media profile. No sign up or registration is required. https://authors.elsevier.com/b/1aZZS,3oKzTK2V
Article
Organophosphate esters (OPEs) are used as flame retardants and plasticizers in many consumer products. Owing to OPEs' toxicity, exposure of organisms in aquatic ecosystems is a concern. Information that pertains to the occurrence and distribution of OPEs in marine aquatic environment, however, is scarce. In this study, concentrations and profiles o...
Article
Full-text available
Normal maternal thyroid function during pregnancy is essential for fetal development and depends upon an adequate supply of iodine. Little is known about how iodine status is associated with preterm birth and small for gestational age (SGA) in mildly iodine insufficient populations. Our objective was to evaluate associations of early pregnancy seru...
Article
Full-text available
Background: Titanium dioxide (TiO2) nanoparticles are among the most manufactured nanomaterials in the industry, and are used in food products, toothpastes, cosmetics and paints. Pregnant women as well as their conceptuses may be exposed to TiO2 nanoparticles; however, the potential effects of these nanoparticles during pregnancy are controversial...
Article
The occurrence and profiles of 15 organophosphate flame retardants/plasticizers (OPFRs) (3 chlorinated [Cl-], 2 aryl-, 5 non-Cl alkyl-, and 5 other types of OPFRs) were investigated in indoor air and dust collected from various microenvironments, including homes in the Albany area of New York State, United States. Concurrent indoor air and dust wer...
Article
Introduction: Iodine is essential for thyroid function, and iodine deficiency during pregnancy is common in Europe and the USA. However, no published studies have examined the role of iodine deficiency in the relation between thyroid function and gestational diabetes mellitus (GDM). Material and methods: We conducted a population-based, nested c...
Article
In the 2000s, nail polish manufacturers started promoting "3-Free" products, phasing out three widely publicized toxic chemicals: toluene, formaldehyde, and dibutyl phthalate (DnBP). However, DnBP was sometimes replaced by another endocrine-disrupting plasticizer, triphenyl phosphate (TPHP). Many new " n-Free" labels have since appeared, without an...
Article
Full-text available
In this study, extraction, clean-up and instrumental analytical conditions were optimized for identifying and quantifying methyl-, chloromethyl-benzi-, octyl-isothiazolinone (MIT, CMIT, BIT, OIT) and 3-iodo-2-propynyl butyl carbamate (IPBC), widely used biocidal active ingredients in human hygiene consumer products. Accuracy of the developed ultras...
Article
At a sewage treatment plant, 27 polybrominated diphenyl ethers, 17 methoxylated brominated diphenyl ethers, nine hydroxylated brominated diphenyl ethers, three hexabromocyclododecane diastereomers, and tetrabromobisphenol A were monitored at five major treatment stages (the influent, primary settlement stage, biological reaction stage, secondary se...
Article
Dried blood spots (DBS), collected for newborn screening programs in the United States, have been used to screen for congenital metabolic diseases in newborns for over 50 years. DBS provide an easy and inexpensive way to collect and store peripheral blood specimens, and present an excellent resource for studies on the assessment of chemical exposur...
Article
h i g h l i g h t s • The distributions of PBDEs and their structural analogues were compared between marine (near-and offshore) and inland. • PBDEs dominated in abiotic media, whereas MeO-BDEs were dominant in biota. • Natural formation might be the main mechanism for PBDE structural analogues in marine and was highly occurred than in inland. • Th...
Article
A colorimetric aptamer/gold nanoparticle (AuNP) sensor to detect 6-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether (6-OH-BDE-47) was developed using AuNPs and a 6-OH-BDE-47-specific ssDNA aptamer. 6-OH-BDE-47 is mono hydroxyl-substituted form of a major congener (2,2′,4,4′-tetrabromodiphenyl ether, BDE-47) of the polybrominated diphenyl ethers (PBDEs),...
Poster
The concentrations and relative distributions of 27 polybrominated diphenyl ethers (PBDEs) and 17 methoxylated (MeO-) and eight hydroxylated (OH-) BDEs were determined in marine environments including sediments, bivalves, and seawater along the coast of South Korea to understand their fates and possible formation mechanisms.
Article
The occurrence and fate of 14 triester organophosphate flame retardants (OPFRs) and plasticizers and their two diester metabolites were investigated in a wastewater treatment plant (WWTP) in the Albany area of New York State. All target OPFRs were found in wastewater, with average concentrations that ranged from 20.1 ng/L for tris(methylphenyl) pho...
Article
The dissolved phase compound and congener specific distribution characteristics of three widely used brominated flame retardants (BFRs) comprising 27 polybrominated diphenyl ethers (PBDEs), 12 hydroxylated and methoxylated metabolites (OH- and MeO-BDEs), 3 hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) were investigated in influe...
Article
Exposure to perfluoroalkyl substances (PFASs) may disrupt thyroid systems, though the specific effects of PFASs are still being elucidated. Since research regarding exposure in infants is highly limited, our goal was to investigate exposure levels of PFASs in infant serum and correlate these levels with thyroid hormones (THs). This was accomplished...
Article
The occurrence and distribution of eight UV filters benzophenone (BP), benzophenone-3 (BP-3), ethylhexyl methoxy cinnamate (EHMC), 4-methylbenzylidene camphor (4-MBC), 2-ethylhexyl 4-dimethylaminobenzoate (OD-PABA), 2-ethylhexyl salicylate (EHS), isoamyl benzoate, and benzyl cinnamate in eleven sites among three rivers, five sewage treatment plants...
Article
The concentrations, congener profiles, and phase-specific distribution profiles of 27 polybrominated diphenyl ethers and 10 hydroxylated and 18 methoxylated brominated diphenyl ethers (OH- and MeO-BDEs; later called structural analogues of PBDEs) were determined in surface soil, water, air, and vegetation from the southeastern city of Busan, Korea...
Article
Twelve organotins (methyl-, octyl-, butyl-, and phenyl-tin), and eight tin-free antifouling paints and their degradation products were measured in marine sediments from the Korean coastal area, and Busan and Ulsan bays, the largest harbor area in Korea. The total concentration of tin-free antifouling paints was two- to threefold higher than the tot...
Poster
compound and congener specific distribution characteristics of mono- to deca-BDEs, their structural analogues (tri- to penta- MeO- and OH-BDEs), three diastereomers of HBCDDs and TBBPA along the type of treatment plant, removal trend for each type of treatment, relationship with inflowing source wastewater was investigated. The wastewater was colle...
Article
Brominated flame retardants were analyzed in sediment samples from the Nakdong River basin, Korea. The total concentrations of the 27 polybrominated diphenyl ethers (PBDEs), including decabrominated diphenyl ether (BDE 209), analyzed were 0.55-300ngg(-1) dry weight (dw), the BDE 209 concentrations were 0.39-190ngg(-1)dw, the tetrabromobisphenol A (...
Article
PBDEs (polybrominated diphenyl ehters) are rarely dissolved in water due to their strong hydrophobicity and large molecular mass so not many researches were done in aqueous environment compared to other environmental compartments. However, the mass loading from wastewater treatment plant into aquatic environment, re-suspension from bottom sediment...
Article
In this work, we investigated exposure levels, distribution patterns, and potential harmful impacts of polybrominated diphenyl ethers (PBDEs) on thyroid hormone activity in 26 children with congenital hypothyroidism and their mothers' pair and 12 normal control pairs. The average concentration of PBDEs in congenital hypothyroidism (median: 22.16 ng...
Article
In this study, we investigated concentration, congener distribution pattern, and effects of potential environmental factors that affect PBDE accumulation. We also estimated correlation between PBDE concentration and health status or thyroid function by analyzing 90 cord blood and 21 breast milk samples obtained from Korean population. Seven from tr...
Article
Six polycyclic musks (PCMs) and five nitro musks (NMs) were analyzed in dewatered sludge samples from 13 municipal, 4 livestock and 1 pharmaceutical wastewater treatment plants (WWTPs) in South Korea. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB; Galaxolide), Abbalide), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-te...

Questions

Questions (2)
Question
Specifically, I wanted to run small reactor of simulating conventional activated sludge of sewage treatment plant to assess the biodegradation and transformation potential for organic chemicals. What I need to know is 1) how to run and maintain the reactor properly (please give me some good reference, if you know any) with minimizing systematic error (such as dead by chemical itself) and 2) are there any standard protocol to extract organic chemicals from single or mixture community of microorgaisms? If there is not, I'm considering to follow the analytical procedure of organic chemicals for sewage sludge instead. Is this too rough idea or maybe possible? Thanks in advance for your professional advice.
Question
More specifically, I'd like to use CDI as liking reagent between OH-hydrophobic halogenated compounds (e.g. OH-bromodiphenyl ethers) and, so therefore, to link this conjugated compounds to -NH2. Are there any known conditions to make this reaction successfully? Please give me some rule of thumb or know-hows. Thanks.

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Projects

Projects (4)
Project
We are organizing a session (Challenges, Innovations & Assessments in Environmental Chemistry: Human Exposure to Emerging & Replacements of Organic Contaminants) in the upcoming ACS Spring (EnviroChem) meeting. Please submit your abstract by 19th January 2021. https://acsenvr.com/website/wp-content/uploads/2020/12/201214Spring2021_ENVR_CFP.pdf
Project
Special Issue Information Dear Colleagues, We are organizing a Special Issue on “Human Exposure to Emerging Flame Retardants and Alternative Plasticizers” for the International Journal of Environmental Research and Public Health (IJERPH). Some of the chemicals that have been used in consumer products have been found to be toxic, and their exposure in humans is linked to various environmental diseases, such as hormonal dysfunction, neurological disorders, kidney diseases, and various cancers. Hence, there has been a rapid increase in the replacement of such harmful chemicals with alternative chemicals in consumer products. However, the toxicity profiles of such emerging alternative chemicals are often either unclear, or they tend to possess similar toxicity to the original toxic chemicals. Thus, it is important to assess the exposure levels and sources of such emerging replacement chemicals and their associated impacts on human health. Among environmental chemicals, plasticizers and flame retardants are a group of high production volume chemicals that have been extensively used for domestic and industrial purposes. In recent decades, some of the harmful legacy chemicals used as plasticizers and flame retardants have been replaced with several alternatives, leading to inevitable exposure to these emerging chemicals in humans and their potential release into the environment. However, there is still a dearth of information on some of these replacement chemicals, such as their exposure levels in various populations, cumulative risk assessments, associated biomarkers, health outcomes, exposure pathways, toxicological effects, reference doses, threshold values, etc. Therefore, this Special Issue is mainly focused on research works addressing these critical issues and expanding the knowledge of emerging replacement chemicals. Studies on target compounds such as OPFRs, NBFRs, polychlorinated flame retardants (Dechlorane Plus), TBBPA, HBCDs, PFAS replacements, melamine, DINCH, BPA alternatives, terephthalate, and other emerging relevant chemicals will be given high priority. We encourage the submission of original research or review articles emphasizing these emerging contaminants using biomonitoring studies (including metabolites and transformation products in humans), epidemiological investigations and other exposome approaches, exposure assessment studies (via food and environmental monitoring), and data-mining and informatics approaches to this Special Issue. Manuscripts reporting novel analytical methods (sampling and analytical strategies) and toxicological studies conducted on these emerging chemicals and their metabolites are also welcomed. Guest Editors Dr. Karthikraj Rajendiran Dr. Tao Zhang Dr. Un-Jung Kim Dr. Maria Pilar Martinez-Moral Special issue details on IJERPH website: https://www.mdpi.com/journal/ijerph/special_issues/Emerging_Flame_Retardants