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RISS 인기검색어
- 검색키워드
- 저자 : Kurunthachalam Kannan (검색결과 12 건)
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Jeon, Junho,Kannan, Kurunthachalam,Lim, Byung J.,An, Kwang Guk,Kim, Sang Don Royal Society of Chemistry 2011 Journal of environmental monitoring Vol.13 No.6
<P>The influence of salinity and organic matter on the distribution coefficient (<I>K</I><SUB>d</SUB>) for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in a brackish water–clay system was studied. The distribution coefficients (<I>K</I><SUB>d</SUB>) for PFAs onto inorganic clay surfaces increased with salinity, providing evidence for electrostatic interaction for the sorption of PFAs, whereas the relationship between <I>K</I><SUB>d</SUB> and organic carbon content (<I>f</I><SUB>oc</SUB>) suggested that hydrophobic interaction is the primary driving force for the sorption of PFAs onto organic matter. The organic carbon normalized adsorption coefficient (<I>K</I><SUB>oc</SUB>) of PFAs can be slightly overestimated due to the electrostatic interaction within uncoated inorganic surfaces. In addition, the dissolved organic matter released from coated clay particles seemed to solvate PFA molecules in solution, which contributed to a decrease in <I>K</I><SUB>d</SUB>. A positive relationship between <I>K</I><SUB>d</SUB> and salinity was apparent, but an empirical relationship for the ‘salting-out’ effect was not evident. The <I>K</I><SUB>d</SUB> values of PFAs are relatively small compared with those reported for persistent organic pollutants. Thus, sorption may not be a significant route of mass transfer of PFAs from water columns in estuarine environments. However, enhancement of sorption of PFAs to particulate matter at high salinity values could evoke potential risks to benthic organisms in estuarine areas.</P> <P>Graphic Abstract</P><P>This study was initiated to provide insight into fate (<I>e.g.</I>, sorption to clay particles) of perfluoroalkyl acids (PFAs), <I>i.e.</I> perfluorooctane sulfate (PFOS) and perfluorooctanic acid (PFOA), in estuarine environments where salinity and organic matter play crucial roles as environmental factors. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0em00791a'> </P>
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Effect of storage time and temperature on levels of phthalate metabolites and bisphenol A in urine
Guo, Ying,Wang, Lei,Kannan, Kurunthachalam Techno-Press 2013 Advances in environmental research Vol.2 No.1
Urine is a widely used matrix in biomonitoring studies on the assessment of human exposure to environmental chemicals such as phthalate esters and bisphenol A (BPA). In addition to the need to apply valid analytical techniques, assurance of specimen integrity during collection and storage is an important prerequisite for the presentation of accurate and precise analytical data. One of the common issues encountered in the analysis of non-persistent contaminants is whether shipping and storage temperature and time since collection have an effect on sample integrity. In this study, we investigated the stability of phthalate metabolites and BPA in spiked and unspiked urine samples stored at room temperature ($20^{\circ}C$) or at $-80^{\circ}C$ for up to 8 weeks. Concentrations of phthalate metabolites declined, on average, by 3% to 15%, depending on the compounds, and BPA declined by ~30% after 4 weeks of storage of spiked urine samples at $20^{\circ}C$. In a test of 30 unspiked urine samples stored at $20^{\circ}C$ and at $-80^{\circ}C$ for 8 weeks, the concentrations of phthalate metabolites and BPA decreased by up to 15% to 44%, depending on the compound and on the samples. It was found that the small reduction in phthalate concentrations observed in urine, varied depending on the samples. In a few urine samples, concentrations of phthalate metabolites and BPA did not decline even after storage at $20^{\circ}C$ for 8 weeks. We found a significant relationship between concentrations of target analytes in urine stored at $20^{\circ}C$ and at $-80^{\circ}C$ for 8 weeks. We estimated the half-lives of phthalate metabolites and BPA in urine stored at $20^{\circ}C$. The estimated half-life of monoethyl phthalate (mEP) and mono (2-ethyl-5-carboxyphentyl) phthalate (mECPP) in urine stored at $20^{\circ}C$ was over two years, of mono (2-ethyl-5-oxohexyl) phthalate (mEOHP) and monobenzyl phthalate (mBzP) was approximately one year, and of other phthalate metabolites was approximately 6 months. The estimated half-life of BPA in urine stored at $20^{\circ}C$ was approximately 3 months, which is much longer than that reported for aquatic ecosystems.
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Lee, Kyu-Tae,Kannan, Kurunthachalam,Shim, Won-Joon,Koh, Chul-Hwan The Korean Society of Oceanography 1998 Journal of the Korean Society of Oceanography Vol.33 No.4
To elucidate contamination levels and distribution of methyl mercury (Me-Hg) in Korean coastal areas, 126 sediment samples were collected from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa during 1995-1996, and the Me-Hg concentrations were determined by cold vapor atomic fluorescence spectrometry (CVAFS). Contamination levels of Me-Hg in sediments from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa were 274 ${\pm}$ 990, 108 ${\pm}$ 24, 294 ${\pm}$ 342, and 1080 ${\pm}$ 760 pg/g, respectively. Concentrations of Me-Hg in sediments were significantly correlated with total organic carbon and sulfur contents, but were independent of mud contents and mean grain size. The highest concentration of Me-Hg (7100 pg/g) was observed at Incheon North Harbor (Site Kl9) in Kyeonggi Bay. This Me-Hg concentration was one or two orders of magnitude higher than those in other Kyeonggi Bay sediments were. The average concentration of Me-Hg in sediments from Lake Shihwa was higher than in those from other study areas. The three peaks of Me-Hg concentrations were observed on three sites (55, 56,and 510) in Lake Shihwa and gradually decreased in distance-dependent manner around these sites. High concentrations of Me-Hg at surface and 10-cm sediment depth in Chinhae Bay maybe due to higher rates of methylation process by active sulfate-reducing bacteria or higher concentrations of total mercury available to sulfate-reducing bacteria.
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Lee, Sang-Yoon,Lee, Sunggyu,Choi, Minkyu,Kannan, Kurunthachalam,Moon, Hyo-Bang Elsevier 2018 Environmental pollution Vol.236 No.-
<P><B>Abstract</B></P> <P>Environmental contamination by siloxanes is a matter of concern due to their widespread consumption in personal care as well as industrial products and potential toxicity. Nevertheless, methods for simultaneous determination of cyclic and linear siloxanes in sediment are lacking. In this study, we developed an optimized analytical method to determine cyclic and linear siloxanes based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). This method was applied to determine concentrations of 19 siloxane compounds in surface and core sediments from industrialized bays in Korea to assess contamination status, spatial distribution, and historical trends. Total concentrations of siloxanes ranged from 15.0 to 11730 (mean: 712) ng/g dry weight, which were similar to or higher than those reported in other countries. The highest concentrations of siloxanes were found in rivers/streams that discharge into coastal waters and bays close to industrial complexes, indicating that industrial activities are major sources of siloxane contamination. Cyclic siloxanes such as D5 and D6 were predominant in surface and core sediments. A significant correlation existed between the concentrations of cyclic and linear siloxanes, suggesting similar sources in the marine coastal environment. The historical record of cyclic siloxanes in core sediments revealed a clear increasing trend since the 1970s. This finding is consistent with the history of local industrialization and global production of siloxanes. This is the first study of historical trends in siloxanes in the coastal environment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An optimized method was developed for simultaneous determination of cyclic and linear siloxanes in sediment. </LI> <LI> Highest levels of linear siloxanes were found in stream sediment. </LI> <LI> Cyclic siloxanes such as D5 and D6 were predominant in surface and core sediments. </LI> <LI> Historical record of siloxanes in sediment core showed a clear increase since the 1970s. </LI> <LI> Historical trend of siloxanes matched well with the history of industrialization and global production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
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In situ measurement-based partitioning behavior of perfluoroalkyl acids in the atmosphere
Seung-Kyu Kim,Donghao Li,Kurunthachalam Kannan 대한환경공학회 2020 Environmental Engineering Research Vol.25 No.3
Environmental fate of ionizable organic pollutants such as perfluoroalkyl acids (PFAAs) are of increasing interest but has not been well understood because of uncertain values for parameters related with atmospheric interphase partitioning behavior. In the present study, not only the values for air-water partition coefficient (KAW) and dissociation constant (pKa) of PFAAs were induced by adjusting to in situ measurements of air-water distribution coefficient between vapor phase and rainwater but also gas-particle partition coefficients were also estimated using three-phase partitioning model of ionizable organic pollutants, in situ measurements of PFAAs in aerosol and air vapor phase, and obtained parameter values. The pKa values of PFAAs we obtained were close to the minimum values suggested in literature except for perfluorooctane sulfonic acids, and COSMOtherm-modeled KAW values were assessed to more appropriate among suggested values. When applying parameter values we obtained, it was predicted that air particle-associated fate and transport of PFAAs could be negligible and PFAAs could distribute ubiquitously along the transection from urban to rural region by pH-dependent phase transfer in air. Our study is expected to have some implications in prediction of the environmental redistribution of other ionizable organic compounds.
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Lee, Sunggyu,Liao, Chunyang,Song, Geum-Ju,Ra, Kongtae,Kannan, Kurunthachalam,Moon, Hyo-Bang Elsevier 2015 CHEMOSPHERE - Vol.119 No.-
<P><B>Abstract</B></P> <P>Due to the regulation on bisphenol A (BPA) in several industrialized countries, the demand for other bisphenol analogues (BPs) as substitutes for BPA is growing. Eight BPs were determined in sludge from 40 representative wastewater treatment plants (WWTPs) in Korea. Total concentrations of BPs (ΣBP) in sludge ranged from <LOQ to 25700ngg<SUP>−1</SUP>. The highest concentrations of ΣBP were found in sludge collected from WWTPs that received discharges from the paper and textile industries. The profiles of BPs were dependent on the proportions of industrial wastewater treated at each of the WWTPs. The sludge from industrial WWTPs contained elevated proportions of BPA, whereas sludge from domestic WWTPs was dominated by bisphenol F (BPF), suggesting use of BPF in certain industrial products in Korea. No significant correlations were found between BPs and the WWTP characteristics. The average per-capita emissions of BPs ranged from 0.04 (BPP) to 886gcapita<SUP>−1</SUP> d (BPA) through WWTP discharges. The emission fluxes of ΣBP through industrial WWTPs were 2–3 orders of magnitudes higher than those calculated for domestic WWTPs, indicating that industrial discharges are the major source of BPs into the Korean environment. This is the first nationwide survey of BPs in sludge from Korean WWTPs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Occurrence of several BP analogues in sludge was confirmed. </LI> <LI> High levels of bisphenol A were found in industrial WWTP sludge. </LI> <LI> Emission fluxes of bisphenols via WWTPs in Korea were estimated. </LI> <LI> This is the first nationwide survey to determine BP analogues in sewage sludge of Korea. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
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Jin, Xiangzi,Lee, Sunggyu,Jeong, Yunsun,Yu, Jae-Pyoung,Baek, Woon Kee,Shin, Kyung-Hoon,Kannan, Kurunthachalam,Moon, Hyo-Bang Elsevier 2016 Environmental pollution Vol.219 No.-
<P><B>Abstract</B></P> <P>Few studies have been conducted on the alternatives to legacy flame retardants in avian species worldwide. In this study, polybrominated diphenyl ethers (PBDEs) and alternative flame retardants such as novel brominated flame retardants (NBFRs) and dechlorane plus (DP) were determined in livers of 10 species of birds from Korea to elucidate species-specific accumulation, biological factors that affect accumulation, and bioaccumulation potentials of these contaminants. Among the emerging alternative flame retardants, the highest occurrence was found for bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEHTBP), <I>syn</I>-DP, <I>anti</I>-DP, and decabromodiphenyl ethane (DBDPE). PBDE concentrations (median: 17.1 ng/g lipid wt) measured in our study were within the ranges reported in previous studies, while the concentrations of BEHTBP, BTBPE and DP were greater than those reported earlier. Residential predatory birds showed significantly greater concentrations of PBDEs and NBFRs than migratory predators and passerine birds. The concentrations of PBDEs, BEHTBP, and DP in residential predatory birds were significantly correlated with increasing stable nitrogen isotope ratio (δ<SUP>15</SUP>N), which indicated biomagnification potentials of these contaminants. Our results suggest that the concentrations and accumulation patterns of PBDEs, NBFRs, and DP depend on the feeding habits and migration patterns of avian species. This is the first report on the accumulation of emerging alternatives to PBDEs in birds from Korea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PBDEs, NBFRs, and DP were detected in liver tissues of 10 Korean bird species. </LI> <LI> BEHTBP, DP, and DBDPE showed higher detection rates. </LI> <LI> The highest levels of DP were found in Korean bird on a global scale. </LI> <LI> Contamination levels and congener profiles of PBDEs varied by diet and habitat. </LI> <LI> PBDEs, BEHTBP, and DP biomagnified in residential predatory birds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
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