Takeshi Nakano

Osaka University | Handai · Research Center for Environmental Preservation

Regarding chlorinated paraffins that have attracted attention recently, we conducted a comparative study of analytical methods for medium-chain chlorinated paraffin (MCCP). To facilitate a comparison of analytical methods for MCCP, an MCCP composite was prepared by mixing fixed amounts of alkanes with 14 to 17 carbon atoms and then reacting chlorin...

Per- and polyfluoroalkyl substances (PFAS) have emerged as a significant class of pollutants due to their broad environmental and health implications. PFAS have been used in a range of industrial and consumer applications since the 1940s, leading to their widespread presence in the environment, including among others, water sources, soil, and even...

Short-chain chlorinated paraffins (SCCPs) are listed in the Stockholm Convention. Therefore, selecting suitable methods for their accurate quantification is essential. Nowadays, the quality of commercial reagents employed as quantification standards is not guaranteed. As a solution, we adopted an SCCP formulation reference material with known homol...

Bacterial cytochrome P450 monooxygenase P450BM3 is a promising enzyme to provide novel substrate specificity and enhanced enzymatic activity. The wild type (WT) has been shown to metabolize the widely distributed polychlorinated biphenyl (PCB) 2,3',4,4',5-pentachlorobiphenyl (CB118) to hydroxylated metabolites. However, this reaction requires the c...

Chiral polychlorinated biphenyls (PCBs) have atropisomers that have different axial chiralities and exist as racemic mixtures. However, biochemical processes often result in the unequal accumulation of these atropisomers in organisms. This phenomenon leads to enantiospecific toxicity enhancement or reduction because either of the atropisomers mainl...

Although polychlorinated biphenyls (PCBs) were commercially banned half a century ago, contamination of the environment and organisms by PCBs is still observed. PCBs show high persistence and bioaccumulation, resulting in toxicity. Among PCBs, chiral PCBs with more than three chlorine atoms at the ortho-position exhibit developmental and neurodevel...

Cytochrome P450 (CYP) monooxygenases play critical roles in determining the toxicity of polychlorinated biphenyls (PCBs) in mammals. Hydroxylation of PCBs by these enzymes leads to increased water solubility, promoting the elimination of PCBs from the body. The CYP1 family is mainly responsible for metabolizing PCBs that exhibit a dioxin-like toxic...

Chlorinated paraffins (CPs) are industrial chemicals that have been primarily used in applications involving metalworking fluids. Among CPs, short-chain chlorinated paraffins (SCCPs) are a well-known environmental pollutant and are listed under Annex A of the Stockholm Convention on Persistent Organic Pollutants. CPs are alkanes substituted with ch...

Persistent organic pollutants (POPs) are lipophilic, persistent and bioaccumulative toxic compounds. In general, they are considered resistant to biological, photolytic, and chemical degradation and polychlorinated biphenyls (PCBs) belong to these chemicals. PCBs were never produced in Serbia, but they were imported and mainly used in electrical eq...

Chlorinated paraffins (CPs) are primary industrial chemicals that have been mainly used in some industrial applications, such as flame retardants, metalworking fluids, and other. Among CPs, short-chain chlorinated paraffin (SCCP) has also been known to be persistent and long-range transport. Moreover, SCCP is registered as listed chemicals under An...

Polycyclic aromatic hydrocarbons (PAHs) from petroleum and fossil fuels are one of the most dominant pollutants in the environment. Since aromatic fraction from petroleum diesel fuel is mainly composed of PAHs, it is important to discover new microorganisms that can biodegrade these compounds. This article describes the biodegradation of the aromat...

2,3',4,4',5-Pentachlorobiphenyl (CB118) is one of the most abundant polychlorinated biphenyl (PCB) congeners in the environment, and perfluoroalkyl acids, including perfluorocarboxylic acids (PFCAs), are widely distributed in the environment. Although CB118 and perfluoroalkyl acids are present in all humans and biota, effects in the metabolic fate...

Hydroxylated polychlorobiphenyls (OH-PCBs) are major metabolites of PCBs that are widely distributed in the environment. While the effects of penta- to hepta-chlorinated OH-PCBs on neuronal differentiation have been widely reported, those of lower chlorinated OH-PCBs have not been extensively studied. To investigate the effects of lower chlorinated...

2,2′,3,5′,6-Pentachlorobiphenyl (PCB 95) and 2,2′,3,4,4′,5′,6-heptachlorobiphenyl (PCB 183) possess axial chirality and form the aS and aR enantiomers. The enantiomers of these congeners have been reported to accumulate in the human body enantioselectively via unknown mechanisms. In this study, we determined the cytochrome P450 (CYP) monooxygenase...

In this study, we analyzed hydroxylated polychlorinated biphenyls (OH-PCBs) in urine of both PCB transport workers and PCB researchers. A method to monitor OH-PCB in urine was developed. Urine was solid-phase extracted with 0.1% ammonia/ methanol (v/v) and glucuronic acid/sulfate conjugates and then decomposed using β-glucuronidase/arylsulfatase. A...

We investigated the capability of microorganisms isolated from environments polluted with perfluoroalkyl acids (PFAAs) to conduct biotransformation of these emerging pollutants. Two different microbial consortia (chemoorganoheterotrophic bacteria and total yeast and molds) were isolated from two river sediments in Saitama and Osaka, Japan, known fo...

Fully brominated diphenyl ether (BDE-209) is a flame retardant widely used in plastics and textiles. Because of its high persistence, humans are exposed to it continuously, mainly via dust ingestion. We investigated effects of BDE-209 on renal function and oxidative stress development in the kidney after subacute exposure in rats. Five groups of an...

A novel clean-up technology to remove polycyclic aromatic hydrocarbons (PAHs) from solid samples by magnetic separation using a composite containing iron powder as a magnetic material and activated carbon as an adsorbent in the freeze-dried calcium alginate matrix (Fe-AC-alg) has been developed. The Fe-AC-alg powder (50 mg), mixed with 1.0 g of gla...

We developed capillary zone electrophoresis (CZE) with indirect UV detection for the determination of fluoride (F−) in seawater using transient isotachophoresis (tITP) as an on-line concentration procedure. A method of correcting sample salinity effects was also proposed so that F− concentrations were obtained using a calibration graph. The propose...

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for simultaneously measuring bisphenol A (BPA), chlorinated BPAs (ClxBPAs), and brominated BPAs (BryBPAs) unintentionally generated in wastewater treatment plants (WWTPs). The main purpose of this study was to develop a non-derivatizing measurement method based on LC/M...

Nineteen ortho-substituted PCBs are chiral and found enantioselectively enriched in ecosystems. Their differential actions on biological targets are not understood. PCB 95 (2,2',3,5',6-pentachlorobiphenyl), a chiral PCB of current environmental relevance, is among the most potent towards modifying ryanodine receptors (RyR) function and Ca2+ signali...

The red-crowned crane (Grus japonensis) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240ng/g lipid weight), follow...

Although Vietnam's massive herbicide exposure in 1960s and 1970s was clearly injurious to health, not all causal relationships have been clarified. We therefore explored associations among dioxins, steroid hormones, age and prostate cancer risk in men. We compared serum levels of dioxin, steroid hormones and prostate specific antigen (PSA) in men a...

Circular dichroisms (CDs) of the o,p'-isomers of 1,1,1-trichloro- and 1,1-dichloro-2,2-bis(chlorophenyl)ethanes (DDT and DDD) were investigated experimentally and theoretically. A series of strong Cotton effect peaks in a characteristic negative-negative-positive-negative, or its mirror-imaged, pattern were observed in the CD spectra of these persi...

The particle size distribution of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) in particulate matter (PM) in Japan is examined for the first time. PM was collected using a PM0.1 air sampler with a six-stage filter. PM was collected in October 2014 and January 2015 to observe potential seasonal variation in the atmospheric behavior and size...

Perfluoroalkyl acids (PFAAs) including perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples taken from Ajifu Waterway in Osaka city, from Osaka Bay, and from Kagoshima Bay, as well as in fifteen seawater samples collected from Osaka Bay and coastal waters of Western Japan. In all sediment sampl...

A CeO2-ZrO2Bi2O3 (CZB) solid solution supported on a mesoporous silica support, SBA-16 (Santa Barbara Amorphous No. 16; SBA), was synthesized using hydrothermal and impregnation methods and was used as a catalyst for the liquid-phase oxidation of bisphenol-A (BPA). CZB was successfully inserted into the mesoporous structure of SBA. For CZB/SBA, the...

The objective of this study was to stimulate microbial biodegradation of petroleum pollution in groundwater and to analyze changes in the abundance and distribution of organic compounds detectable in petroleum. Bioremediation was conducted in a closed bipolar system, by bioaugmentation with consortia of hydrocarbon degrading microorganisms (HD) and...

Dechlorane Plus (DP) is a chlorinated flame retardant developed as an alternative for Mirex (Dechlorane) in the1960s, and was detected by Hoh et al. in the environment for the first time in 2006. Thereafter DP as an emerging substance began to be investigated around the world, but the data was not available in Japan until 2011. We investigated cont...

We examined measurement methods of Dechlorane Plus (DP) for HRMS-EI and LRMS-NCI in this report. Both linearity of the calibration curves were excellent. IDL towards the LRMS-NCI and air samples towards the HRMS-EI were sensitive, respectively. The results of DP analysis for ambient air, syn-DP: 0.46-7.7 pg/m³, anti-DP: 1.5-16 pg/m³ and Total DP: 2...

Environmental pollution with toxic metals, petroleum-type contaminants and new classes of Persistent Organic Pollutants (POPs), such as perfluoroalkyl and polyfluoroalkyl substances (PFASs) is always a problem. Microorganisms as ”biological agents” are always actual in remediation, especially in the historical pollution, protection and preservation...

The advance of technology and industry in the last hundred years, population growth and the development of big cities have led to the production of waste materials in quantities which exceed self-purification capacity of nature. The accumulation of waste materials of various origin causes increased pollution of the environment, including soil. Nond...

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are two highly lipophilic classes of persistent organic pollutants (POPs) able to resist degradation and with the ability to bioaccumulate through the food chain. The international community has responded to the threat from POPs by negotiating a global treaty, the Stockholm...

Polychlorinated biphenyls (PCBs) accumulate in mammals via the food chain because of their characteristics such as slow degradation and high hydrophobicity. One of the 209 PCB congeners, 2,3′,4,4′,5-pentachlorobiphenyl (CB118), is abundantly found in the environment and in mammals. Understanding the metabolic fate of CB118 can provide important inf...

The degradation of organic contaminants in actual textile wastewater was carried out by iron carbon (Fe-C) micro-electrolysis. Different Fe-C micro-electrolysis systems (SIPA and SISA) were established by using scrap iron particle (SIP) and scrap iron shaving (SIS) as anode materials. The optimal condition of both systems was obtained at the initia...

The particle size distributions of dechloranes were determined. For collecting PM, an Andersen air sampler equipped with five-stage quartz fiber filters and a PM0.1 air sampler equipped with six-stage Teflon and inertial SUS fiber filters were used. Particulate matter (PM) was collected in April 2014 by Andersen air sampler and October 2014 and Jan...

Using the chemical balance method, and considering the presence of unidentified sources, we estimated the origins of PCB contamination in surface sediments of Muroran Port, Japan. It was assumed that these PCBs originated from four types of Kanechlor products (KC300, KC400, KC500, and KC600), combustion and two kinds of pigments (azo and phthalocya...

Polycyclic aromatic hydrocarbons (PAHs) and chlorinated PAHs (ClPAHs) are ubiquitous contaminants that bind to the aryl hydrocarbon receptor (AhR) and exhibit mutagenic potential. It is difficult to monitor human exposure levels to ClPAHs because the exposure routes are complicated and environmental concentrations are not always correlated with the...

For the precise estimation of the risk to human health caused by persistent organic pollutants (POPs), it is important to discuss enantiomer fraction value (EF value) because it is reported that behaviors such as stability and toxicity of enantiomers are quite different in human body. Among POPs, polychlorinated biphenyl (PCB) is known as one of th...

This paper discusses the concentrations and congener patterns of PCBs unintentionally present in chlorophenylsilanes. Chlorophenylsilanes are used in the production of silicone-based adhesives and phenyl silicones. The concentration of PCBs in adhesives was found to range from not-detectable concentrations to 40 mg/kg. The concentrations of PCBs in...

Urethane-crosslinked β-cyclodextrin polymers are prepared by crosslinking heptakis(2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) with various diisocyanate linkers, such as 4,4′-methylenebis(phenyl isocyanate) (MDI), 1,4-phenylene diisocyanate (PDI) and hexamethylene diisocyanate (HMDI), in DMF. Among these polymers, MDI- and PDI-crosslinked polymers ha...

179 countries (parties) ratified the Stockholm Convention on Persistent Organic Pollutants (POPs), and agreed to destroy polychlorobiphenyls (PCBs) and develop a sound management plan by 2028. Currently still 3 million tons of PCB-contaminated oil and equipment need to be managed under the Convention. Thus, the development of a facile and environme...

This study reports the concentrations and congener partners of polychlorinated biphenyls (PCBs) in commercially available paints. Polycyclic-type pigments containing dioxazine violet (pigment violet (PV) 23, PV37) and diketopyrrolopyrrole (PR254, PR255) were found to contain PCB-56, PCB-77, PCB-40, PCB-5, and PCB-12, and PCB-6, PCB-13, and PCB-15,...

Abstract A recent study found an inverse correlation between serum TCDD levels and serum testosterone in the US veterans, while there is little known on the dioxin and steroid hormones about Vietnamese men. We collected blood samples from 48 men who had resided in a hotspot when exposure happened and 38 men in a non-sprayed area. Some steroid hormo...

Recent studies have found elevated dioxin levels inside some US military former air bases in Vietnam, known as hotspots. Many studies of Agent Orange have been done in the U.S. veterans; however, there is little known about Vietnamese men. In 2010, we collected blood samples from 97 men in a hotspot and 85 men in an unsprayed area in Northern Vietn...

The aim of this study was to investigate 12 perfluorinated compounds (PFCs) including perfluorinated carboxylates (C4-C12) and perfluorinated alkyl sulfonates (C4, C6, and C8) in river and seawater samples to determine contamination levels in the aquatic environment of Hyogo prefecture, Japan. High levels of perfluorohexanoic acid (PFHxA; 2300-16,0...

Products of a thermal reaction of chlorpyrifos were analyzed by LC/MS and GC/MS. As a result, it was found that chlorpyrifos undergoes an elimination reaction of phosphate by a thermal reaction. Furthermore, it is indicated that the structural analogue of 2,3,7,8-TCDD arises by a thermal reaction of chlorpyrifos. In addition, the toxicity of the pr...

In this study, an analytical method for perfluorinated compounds (PFCs) in granular activated carbon (GAC) was investigated. The investigation of analysis was conducted by using GAC which adsorbed PFCs from artificial waste water containing PFCs of known amount. As results, it was confirmed that Accelerated solvent extraction (ASE) method using ace...

Chlorpyrifos is one of the major pesticides used today which has a chlorinated aromatic moiety of a pyridine analogue of 2,4,5-trichlorophenol and can be a potential direct precursor of another pyridine analogue of 2,3,7,8-T4CDD (2,3,7,8-tetrachlorodibenzo-p-dioxin). In the recent study, PCDF compounds have been detected in chlorpyrifos samples, ho...

The concentration levels and congener profiles of polychlorinated biphenyls (PCBs), pentachlorobenzene (PeCBz), and hexachlorobenzene (HxCBz) were assessed in commercially available organic pigments. Among the azo-type pigments tested, PCB-11, which is synthesized from 3,3'-dichlorobendizine, and PCB-52, which is synthesized from 2,2',5,5'-tetrachl...

Two capillary columns of different polarity were applied in a two-dimensional gas chromatography system coupled to a quadrupole mass spectrometric detection (GCxGC/qMS) in order to separate and identify all of the possible 22 isomers of tetra-, 14 of penta- and 10 of hexachloronaphthalene that may occur in selected industrial chemicals. The two-dim...

To efficiently remove and recover perfluorinated compounds (PFCs) such as perfiuorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) from water, surface-tethered beta-cyclodextrins (CDs) on the surface of polystyrene (PS) particles (PS-beta-CDs) were prepared. The PS-beta-CDs with a 36% beta-CD content showed high adsorption capability again...

Perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples from the wastewater canal draining the industrial complex of Pančevo, Serbia (oil refinery, petrochemical plant, and fertilizer factory). The canal is directly connected to Europe's second largest river, the Danube, which drains its water int...

Unintentional formation of polychlorinated biphenyl (PCB) from chemical manufacturing process of organic pigment such as phthalocyanine pigment have been known since 1976. Regarding to unintentional formed congeners in disazo pigment, in the case of 3,3′-dichloro benzidine, PCB-11(3,3′-), PCB-35(3,3′,4-), PCB-77(3,3′,4,4′-) were dominant congeners...

To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogeno...

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals released into the air during the incomplete burning of fossil fuels, such as gasoline and other organic substances. Some PAHs are reasonably anticipated to be human carcinogens. In this study, a high-performance liquid chromatography-tandem mass-spectrometry method has been developed...

抄録 Dechlorane Plusは，1970年代に禁止されたMirex（Dechlorane）の代わりに開発された塩素系難燃剤であるが，近年，欧米や中国での調査報告が急増している．しかしながら，我が国での調査報告例がないことから，著者らは高分解能ガスクロマトグラフィー/電子イオン化質量分析（GC/EI-MS）法を用いて国内の環境汚染の概要調査を実施した．その結果，著者らは我が国の都市域で採取した環境試料から初めてDechlorane Plusを検出した．検出されたDechlorane Plusの濃度は，屋内ダストで2.9～42 ng g⁻¹-dry，窓枠付着粉じんで240～270 ng g⁻¹-dry，路上堆積物で74～150 ng g⁻¹-dry，土壌で1.7 ng g⁻¹-dry，底...

Polychlorinated biphenyls (PCBs) are still of serious concern as a potential health hazard due to their persistency and bioacumulation. Of 209 possible PCB congeners, with varying number and position of chlorine atom(s), 19 are chiral. These are mostly highly chlorinated and tend to remain longer against the biological decompositions, suffering bio...