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Many chemical substances are detectable in house dust, and they are consequently taken into our bodies via the mouth and nose. Triphenyl phosphate (TPhP), a flame retardant that has an estrogen‐like effect in vitro, is present in house dust at high concentrations. Estrogen exposure during development has significant influences on reproductive behavior in rodents, and its effects persist until maturity. In the present study, we investigated the effect of early life exposure to TPhP on the reproductive behavior of female rats. Oral treatment with TPhP (25 or 250 mg/kg), ethinyl estradiol (EE; 15 μg/kg) as a positive control, or sesame oil as a negative control, were given to female rats (from birth to 28 days of age). The 8‐week‐old rats were bilaterally ovariectomized. At 12–15 weeks of age, the rats were subjected to odor preference and sexual behavior tests. In the odor preference test, the oil group showed significantly higher preference for male odor than female odor, but the low‐dose TPhP treatment group lost the preference for male odor, indicating a possible outcome of early life TPhP exposure on sexual recognition. In the sexual behavior test, both the EE and TPhP treatment groups displayed significantly less proceptive behavior. These results suggest that early life exposure to TPhP disturbs the normal sexual behavior of female rats., Triphenyl phosphate (TPhP) is a flame retardant detected in house dust at high concentrations. TPhP exhibits estrogenic effect in vitro; however, its effect remains unclear in vivo. We examined the effects of early life exposure to low (25 mg/kg) and high (250 mg/kg) doses of TPhP in female rats on reproductive behavior. In the case of sexual behavior, TPhP significantly reduced proceptive behavior. This study showed that early life exposure to TPhP disturbs the normal sexual behavior of female rats.

Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used to manufacture several commercial plastic products. The major homologue in commercial PBDE mixtures are listed in the Stockholm Convention on Persistent Organic Pollutants and are scheduled for global elimination. Hence, to understand more about unintentional contamination of plastic recycling stream by restricted PBDEs, we examined 540 small plastic consumer products (1139 components after dismantling), including children's toys, purchased in 18 countries (mainly Japan) between 2015 and 2019. Handheld X-ray fluorescence analysis revealed that 219 plastic components (19% of the total samples) contained bromine at a concentration of >30 mg kg- 1. Chemical analysis of these bromine-positive components revealed that 109 pieces (9.6% of the total), mainly those made of blackcolored plastic, contained PBDEs at concentrations ranging between 35 and 10,000 mg kg- 1, with the maximum contribution from decabromodiphenyl ether (decaBDE). These PBDE concentrations were insufficient to impart flame retardancy, suggesting that the recycled plastic used to manufacture these consumer products probably originated from electronic waste, the manufacture of which was the primary use of commercial decaBDE mixtures. PBDEs were also found in secondary raw plastic materials and their final products obtained in India in 2019, demonstrating that plastics containing decaBDE end up in products where they serve no functional purpose. To contribute to the circular economy, the recycling of plastic waste in end-of-life products should be promoted. However, urgent action is needed to prevent plastic additives of concern, including PBDEs, from entering new products used in daily lives, particularly those used by children.

We screened 583 chemicals for receptor binding activity to the human estrogen receptor (hER), the Japanese medaka estrogen receptor (medER), and the aryl hydrocarbon receptor (AhR) using the yeast two-hybrid assay. The substances tested included substances that could potentially be produced unintentionally by industrial processes, such as halogenated steroids and phenols. Antagonistic effects on hER and the androgen receptor were also screened. The test chemicals were selected for screening on the basis of chemical structure associated with possible estrogen receptor binding activity. The current study presents the report on the screening of 583 chemicals for different kinds of endocrine disrupting activity.

We measured bioaccessible lead (Pb) in simulated gastrointestinal fluids containing Pb-contaminated soil or dust from electronic waste (e-waste) recycling sites to assess the risk of Pb ingestion. The physiologically based extraction test (PBET) was used as in vitro bioaccessibility assay. Pb speciation was determined using X-ray absorption spectroscopy. The total Pb concentrations in dusts ( n = 8) and soils ( n = 4) were in the range of 1630–131,000 and 239–7800 mg/kg, respectively. Metallic Pb, a common component of e-waste, was ubiquitous in the samples. We also found Pb adsorbed onto goethite and as oxides and carbonate, implying soil mixing and weathering influences. Pb phosphate and organic species were only found in the soil samples, suggesting that formation was soil-specific. We identified other Pb compounds in several samples, including Pb silicate, Pb chromate, and Pb(II) hydrogen phosphate. A correlation analysis indicated that metallic Pb decreased bioaccessibility in the stomach, while a Pb speciation analysis revealed a low bioaccessibility for Pb phosphates and high bioaccessibility for organic Pb species. The health risk based on bioaccessible Pb was estimated to be much lower than that of total Pb due to the lower concentrations.

In vitro reporter gene assays detecting dioxin-like compounds have been developed and validated since the middle 1990's, and applied to the determination of dioxin-like activities in various samples for their risk management. Data on characterizing the potency of individual brominated dioxins and their activity in mixture with chlorinated dioxins are still limited on the cell-based assay. This study characterized the dioxin-like activities of the 32 brominated dioxins, such as polybrominated dibenzo-p-dioxins, polybrominated dibenzofurans (PBDFs), coplanar polybrominated biphenyls, mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDFs), as a sole component or in a mixture by DR-CALUX (dioxin-responsive chemically activated luciferase expression) using the rat hepatoma H4IIE cell line and XDS-CALUX (xenobiotic detection systems-chemically activated luciferase expression) assays using the mouse hepatoma H1L6.1 cell line. The 2,3,7,8-TCDD-relative potencies (REPs) of most of the brominated dioxins were within a factor of 10 of the WHO toxicity equivalency factor (WHO-TEF) for the chlorinated analogues. The REPs of a few PXDFs were an order of magnitude higher than the corresponding WHO-TEFs, indicating their toxicological importance. Results with reconstituted mixtures suggest that the activity of brominated and chlorinated dioxins in both CALUX assays was dose-additive. Thus, obtained results indicated the applicability of the CALUX assays as screening tools of brominated dioxins together with their chlorinated analogues.

In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme expert panel recommended the use of the WHO toxicity equivalency factor (TEF) scheme for assessment of the human health risks of brominated dioxins which have different sources from chlorinated dioxins. Therefore, WHO toxic equivalents (TEQs) should be determined for both chlorinated and brominated dioxins. As alternative to the conventional but time-consuming dioxin analysis using gas chromatography high-resolution mass spectrometry, we have developed a screening method involving cleanup and separation of brominated dioxins from chlorinated dioxins in field samples and subsequent analysis by CALUX (chemically activated luciferase expression) assays which are in vitro reporter gene assays detecting dioxin-like compounds. Cleanup and separation were accomplished with silica gel columns impregnated with 55% sulfuric acid and with 10% silver nitrate, respectively, and the average recoveries of the major contributors to the WHO-TEQs were approximately 90%. The CALUX 2,3,7,8-TCDD equivalents (CALUX-TEQs) derived from all the dioxin-like compounds in the cleanup fractions of the field samples (n = 24) were measured by means of the CALUX assays, indicating significant positive correlations between the WHO-TEQs and CALUX-TEQs (r ≥ 0.969, P

The concentrations of organic flame retardants (FRs) and dioxin-like activities in dust collected from five countries were investigated. The correlations between the concentrations of the different groups of FRs and dioxin-like activities were examined. Chlorinated paraffins (CPs, C 9 to C 31 ) were found in the highest concentration (median ∑CP 700 μg/g, range 280–4750 μg/g), followed by organophosphate esters (median ∑ 13 OPEs 56 μg/g, range 21–110 μg/g), halogenated flame retardants (median ∑ 17 HFRs 3.3 μg/g, range 0.87–14 μg/g) and polybrominated diphenyl ethers (median ∑ 17 PBDEs 2.8 μg/g, range 0.46–11 μg/g). There were no significant differences in concentrations of the FRs among the countries but differences in PBDE and CP congener profiles were found. BDE209 predominated in dust from Australia, the UK, Sweden and China, ranging from 50 to 70% of total PBDEs. The lowest percentage of BDE209 was found in the dust from Canada, representing only 20% of total PBDEs. For CPs in dust from Sweden, the long-chain CPs (especially C 18 congeners) predominated, while for other countries, medium-chain CPs (especially C 14 congeners) predominated. The dioxin-activities of the dusts ranged from 58 to 590 pg CALUX-TEQ/g, and had a median of 200 pg CALUX-TEQ/g. There were significant positive correlations between concentrations of PBDEs and CPs with dioxin-like activities. The dioxin-like activity may be due to the presence of polychlorinated or polybrominated dioxin/furans (PBDD/DFs) or polychlorinated naphthalenes (PCNs) in the dust. The PBDD/DFs are known impurities and degradation product of the penta-BDE mixture, and PCNs are known impurities of CPs which exhibit dioxin-like activities.

We investigated the concentrations of polybrominated diphenyl ethers (PBDEs) and alternative flame retardants (FRs) in environmental samples collected in January 2012, 2013, and 2014 from an electronic waste-processing area in northern Vietnam. During the study period, PBDE and alternative FR concentrations in soils around the electronic waste-processing workshops ranged from 37 to 9200 ng g −1 dry weight (dw) and from 35 to 24,000 ng g −1 dw; the concentrations in soils around the open-burning sites ranged from 1.6 to 62 ng g −1 dw and from −1 dw; and the concentrations in river sediments around the workshops ranged from 100 to 3800 ng g −1 dw and from 23 to 6800 ng g −1 dw, respectively. Over the course of study period, we observed significant decreases in concentrations of PBDEs and significant increases in concentrations of alternative FRs, particularly Dechlorane Plus isomers and oligomeric organophosphorus FRs ( o -PFRs) in both soils and sediments around the workshops. We also report information on concentrations and environmental emissions of o -PFRs and their low-molecular-weight impurities in the same soils and sediments. The detection of o -PFR impurities around the workshops and the open-burning sites highlights an enhanced breakdown of o -PFRs probably due to weathering during open storage and high temperature attained during the burning of electronic wastes.

While the production and new use of hexabromocyclododecane (HBCD) mostly ceased after being listed as a persistent organic pollutant under the Stockholm Convention in 2013, its emission from treated products in use to indoor environments still deserves attention. To examine the transfer of HBCD diastereomers to dust on the surface of flame-retarded curtains and to better characterize the potential of treated fabrics to be sources of HBCD in dust, we carried out a series of 196-day experiments using two types of curtains and attached dusts. Concurrently, the physicochemical properties (vapor pressure, water solubility, and octanol–water partition coefficient) of the HBCD diastereomers were measured. HBCD diastereomers migrated from curtains to dust with half-saturation times of about 20–50 days. By day 196, mean HBCD concentrations in dust had reached 13–290 μg/g, depending on the types of curtains and dusts. The composition of HBCD, dominated by γ-HBCD in the curtains, was dominated by α-HBCD in the post-experiment dusts, probably because of the higher vapor pressure of α-HBCD compared to γ-HBCD. The initial HBCD contents of the two curtains were comparable, but the concentrations and profiles of HBCD diastereomers in the post-experiment dusts differed markedly, probably because differences between the texture and/or surface finishing of the treated fabrics affected HBCD transfer to the attached dust.

The present study was conducted to examine the concentrations, profiles, and mass distributions of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), and polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) based on the particle sizes of house dust samples from five homes in Japan. After removal of impurities from house dust from vacuum cleaner bags, selected indoor dust samples were size fractionated (>2 mm, 1–2 mm, 0.5–1 mm, 250–500 μm, 106–250 μm, 53–106 μm, and 250 μm in size and fluffy dust were included. The conclusion is that particulate dust

This study investigated the contamination status of 21 emerging flame retardants (FRs) in soils (n = 32) and river sediments (n = 8) from an e-waste recycling (EWR) site in the northern part of Vietnam. Among analyzed FRs, higher levels of decabromodiphenyl ethane (DBDPE) (ND–4200 ng/g dw), 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) (ND–350 ng/g dw) and Dechlorane Plus isomers (DPs) (ND–65 ng/g dw) were found in soils near EWR workshops and open burning places. The highest concentrations of DBDPE (20 ng/g dw), BTBPE (5.7 ng/g dw) and DPs (6.7 ng/g dw) were also detected in sediments collected from the middle of the EWR site. The levels decreased concomitantly with increasing distance from the EWR site. These results indicate that these FRs were released to the surrounding environment from improper recycling activities, such as manual dismantling of devices and open burning of e-wastes. Moreover, the estimated daily intakes of those FRs via soil ingestion were approximately ten times higher for children than adults. To our knowledge, this is a first comprehensive study on characterization of soil and sediment contamination by a series of emerging FRs at an EWR site in Vietnam.

A series of laboratory experiments were conducted, whereby two HBCDD treated polyester curtain samples were contacted with deionised Milli-Q water as leaching fluid and HBCDD determined in the resulting leachate. As well as single batch (no replenishment of leaching fluid), serial batch (draining of leachate and replenishment with fresh leaching fluid at various time intervals) experiments were conducted. In single batch experiments at 20 °C, ΣHBCDD concentrations increased only slightly with increasing contact time (6 h, 24 h, and 48 h). This is supported by serial batch tests at 20 °C in which leaching fluid was replaced after 6 h, 24 h, 48 h, 72 h, 96 h, and 168 h. Data from these experiments show that while concentrations of HBCDD in leachate after 24 h cumulative contact time exceed those at 6 h; concentrations in samples collected at subsequent contact times remained steady at ∼50% of those in the 24 h sample. Consistent with this, leaching is shown to be second order, whereby a period of initially intense dissolution of more labile HBCDD is followed by a slower stage corresponding to external diffusion of the soluble residue within the textile. In experiments conducted at 20 °C, α-HBCDD is preferentially leached compared to β- and γ-HBCDD. However, at higher temperatures, the relatively more hydrophobic diastereomers are proportionally more readily leached, i.e. raising the temperature from 20 °C to 80 °C increased concentrations of γ-HBCDD in the leachate by a factor of 28-33 while corresponding α-HBCDD concentrations only increased by a factor of 4.3-4.8.

The contents and elution behavior of metals in consumer electronics parts were determined so as to understand their maximum environmental risk. Elements contained most in printed-circuit boards were Cu, Si, Br, Ca, Al, Sn, Pb, Sb, Ba, Fe, Ni, Ti, and Zn; in cathode-ray tube glass were Si, Pb, Ba, Sr, Zn, Zr, Ca, and Sb; in arsenic contained liquid-crystal displays were Si, Ca, Sr, Ba, As, and Fe; and in antimony contained liquid-crystal displays were Si, Ba, Ca, Sb, Sr, Fe, and Sn. The elements eluted most from printed-circuit boards were Zn, Pb, and Cu; from cathode-ray tube glass were Pb, Zn, B, Ba, and Si; and from liquid-crystal displays were B and Si, and the toxic As and Sb. The amount eluted was greatest at acidic pH. It was revealed that officially recommended 6-h-shaking with a pure water test was insufficient to understand the real environmental risk of waste electronics.

Three oligomeric organophosphorus flame retardants (o-PFRs), eight monomeric PFRs (m-PFRs), tetrabromobisphenol A (TBBPA), and polybrominated diphenyl ethers (PBDEs) were identified and quantified in surface soils and river sediments around the e-waste recycling area in Bui Dau, northern Vietnam. Around the e-waste recycling workshops, 1,3-phenylene bis(diphenyl phosphate) (PBDPP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), TBBPA, and PBDEs were dominant among the investigated flame retardants (FRs). The respective concentrations of PBDPP, BPA-BDPP, TPHP, TBBPA and the total PBDEs were 6.6-14000 ng/g-dry

To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270,000 ng g(-1) dry weight (3700-5,500,000 ng g(-1) dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools.

In developing countries, wastes are usually not separated before being disposed of in solid-waste landfills, most of which are open dumps without adequate measures to prevent environmental pollution. To understand the leaching behavior of brominated flame retardants (BFRs) from waste consumer products in landfills, we have been conducting a long-term landfill lysimeter experiment since 2006 under conditions designed to mimic three types of landfill conditions in developing countries: aerobic, semi-aerobic, and anaerobic. Pilot-scale lysimeters (60-cm i.d.) were filled with a 400-cm layer of mixed wastes consisting of 35 wt% food, 20 wt% paper, 20 wt% paper pulp, 13 wt% plastic, 10 wt% wood chips, 1 wt% glass, and 1 wt% metals, proportions that are typical of unsorted municipal solid waste in Asian developing countries. In the present study, we determined the concentrations of polybrominated diphenyl ethers, tetrabromobisphenol A, tribromophenols, and hexabromocyclododecanes in leachate samples collected from the lysimeters during the first 3.5 years of the experiment, to evaluate BFR elution behavior in early-stage landfills. Under all three conditions, BFR elution started at the beginning of the experiment. The BFR concentrations in the leachates from the aerobic lysimeter tended to be lower than those from the anaerobic lysimeter, suggesting that the presence of air inside landfills considerably reduces BFR elution to the surrounding environment. During the 3.5-year experiment, BFR outflow from the lysimeters was only 0.001–0.58% of the total BFRs in the loaded waste; that is, most of the BFRs in the waste remained in the lysimeters.

Chlorinated and non-halogenated organophosphorus flame retardants (OPFRs) including tris(2-chloroisopropyl) phosphate (TCIPP), diethylene glycol bis(di(2-chloroisopropyl) phosphate) (DEG-BDCIPP), triphenyl phosphate (TPHP), and bisphenol A bis(diphenyl phosphate) (BPA-BDPP) have been used increasingly as alternatives to polybrominated diphenyl ethers and other brominated flame retardants. For this study, five batches of incineration experiments of wastes containing approximately 1% of TCIPP, DEG-BDCIPP, TPHP, and BPA-BDPP were conducted using a pilot-scale incinerator. Destruction and emission behaviors of OPFRs were investigated along with the effects on behaviors of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), and pentachlorophenol (PCP). Incineration conditions were chosen according to current regulations for waste incinerators in Japan and UNEP. The OPFRs in the input materials were mainly destroyed in the primary combustion with destruction efficiencies greater than 99.999%. Concentrations of the OPFRs in the exhaust gases and ash were, respectively, < 0.01–0.048 μg m− 3 and < 0.5–68 μg kg− 1. Almost all of the total phosphorus in the input materials was partitioned into the ash, but less into final exit gases, indicating negligible emissions of volatile phosphorus compounds during incineration. Inputs of chlorinated OPFRs did not affect the formation markedly. Destruction and emission behaviors of unintentional POPs were investigated. Emissions of such POPs in exhaust gases and the ash were lower than the Japanese and international standards. Results show that even in wastes with high contents of chlorinated and non-halogenated OPFRs, waste incineration by the current regulations for the waste incinerators can control environmental emissions of OPFRs and unintentional POPs. Incineration is regarded as a best available technology (BAT) for waste management systems.

Non-PBDE (polybromodiphenyl ether) brominated flame retardants (BFRs) used as alternatives to PBDEs should be evaluated in terms of their environmental contamination potential. We first used two well-known estimation tools, EPI Suite and SPARC, to estimate the physicochemical properties of 52 non-PBDE BFRs. We assessed the dependence of the properties on the molecular weight and chemical structure of the compounds. The accuracy of the estimates was evaluated by comparing results with previous experimental data. In the case of EPI Suite, we have recommended an appropriate calculation method for the air-water partition coefficient. Half-lives in each environmental medium were also estimated with EPI Suite. Based on the estimated properties and half-lives, the overall persistence (Pov) and long-range transport potential (LRTP) of the BFRs were calculated using the Organization for Economic Cooperation and Development Pov and LRTP Screening Tool. We selected some POP-like chemicals from among the non-PBDE BFRs on the basis of their Pov and LRTP. From a Monte Carlo analysis of the calculated results for the selected BFRs, we suggest physicochemical properties to be measured in the future.

In this paper, we have compiled and reviewed the most recent literature, published in print or online from January 2010 to December 2012, relating to the human exposure, environmental distribution, behaviour, fate and concentration time trends of polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants, in order to establish their current trends and priorities for future study. More data are now becoming available for remote areas not previously studied, Indian Ocean islands, for example. Decreasing time trends for penta-mix PBDE congeners were seen for soils in northern Europe, sewage sludge in Sweden and the USA, carp from a US river, trout from three of the Great Lakes and in Arctic and UK marine mammals and many birds, but increasing time trends continue in polar bears and some birds at high trophic levels in northern Europe. This may be partially a result of the time delay inherent in long-range atmospheric transport processes. In general, concentrations of BDE209 (the major component of the deca-mix PBDE product) are continuing to increase. Of major concern is the possible/likely debromination of the large reservoir of BDE209 in soils and sediments worldwide, to yield lower brominated congeners which are both more mobile and more toxic, and we have compiled the most recent evidence for the occurrence of this degradation process. Numerous studies reported here reinforce the importance of this future concern. Time trends for HBCDs are mixed, with both increases and decreases evident in different matrices and locations and, notably, with increasing occurrence in birds of prey. Temporal trends for both PBDEs and HBCD in Asia are unclear currently. A knowledge gap has been noted in relation to metabolism and/or debromination of BDE209 and HBCD in birds. Further monitoring of human exposure and environmental contamination in areas of e-waste recycling, particularly in Asia and Africa, is warranted. More data on temporal trends of BDE and HBCD concentrations in a variety of matrices and locations are needed before the current status of these compounds can be fully assessed, and the impact of regulation and changing usage patterns among different flame retardants determined. Crown Copyright (C) 2014 Published by Elsevier Ltd. All rights reserved.

Vapor pressures (pi) of selected brominated flame retardants (BFRs), such as three polybrominated diphenyl ethers, PBDEs, 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99), and 2,2′,4,4′,5,5′-hexabromodiphenyl ether (BDE-153), and two non-PBDE BFRs, hexabromobenzene (HBB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in the temperature range of (313 to 423) K, were measured by the gas saturation method. The standard uncertainties of temperature and vapor pressure measurements were estimated to be within ± 0.08 K and typically ca. ± 3.9 %, respectively. The temperature dependence of pi, namely, enthalpy of sublimation (ΔsubH), was determined by fitting the experimental data with the Clausius–Clapeyron equation. From the equation and our previous works on water solubility, pi and Henry’s law constant at 298 K for those BFRs were predicted. On the basis of these results, the environmental partitioning characteristics were also discussed.

We studied distribution of heavy metals [lead (Pb), copper (Cu) and zinc (Zn)] in surface soil at an electronic-waste (e-waste) recycling workshop near Metro Manila in the Philippines to evaluate the pollution size (spot size, small area or the entire workshop), as well as to assess heavy metal transport into the surrounding soil environment. On-site length-of-stride-scale (~70 cm) measurements were performed at each surface soil point using field-portable X-ray fluorescence (FP-XRF). The surface soil at the e-waste recycling workshop was polluted with Cu, Zn and Pb, which were distributed discretely in surface soil. The site was divided into five areas based on the distance from an entrance gate (y-axis) of the e-waste recycling workshop. The three heavy metals showed similar concentration gradients in the y-axis direction. Zn, Pb and Cu concentrations were estimated to decrease to half of their maximum concentrations at ~3, 7 and 7 m from the pollution spot, respectively, inside the informal e-waste recycling workshop. Distance from an entrance may play an important role in heavy metal transport at the soil surface. Using on-site FP-XRF, we evaluated the metal ratio to characterise pollution features of the solid surface. Variability analysis of heavy metals revealed vanishing surficial autocorrelation over metre ranges. Also, the possibility of concentration prediction at unmeasured points using geostatistical kriging was evaluated, and heavy metals had a relative "small" pollution scales and remained inside the original workshop compared with toxic organohalogen compounds. Thus, exposure to heavy metals may directly influence the health of e-waste workers at the original site rather than the surrounding habitat and environmental media.

We conducted this study to assess the occurrence, profiles, and toxicity of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) and brominated polycyclic aromatic hydrocarbons (Br-PAHs) in e-waste open burning soils (EOBS). In this study, concentrations of 15 PAHs, 26 Cl-PAHs and 14 Br-PAHs were analyzed in EOBS samples. We found that e-waste open burning is an important emission source of Cl-PAHs and Br-PAHs as well as PAHs. Concentrations of total Cl-PAHs and Br-PAHs in e-waste open burning soil samples ranged from 21 to 2800 ng/g and from 5.8 to 520 ng/g, respectively. Compared with previous studies, the mean of total Cl-PAH concentrations of the EOBS samples in this study was higher than that of electronic shredder waste, that of bottom ash, and comparable to fly ash from waste incinerators in Korea and Japan. The mean of total Br-PAH concentrations of the EOBS samples was generally three to four orders of magnitude higher than those in incinerator bottom ash and comparable to incinerator fly ash, although the number of Br-PAH congeners measured differed among studies. We also found that the Cl-PAH and Br-PAH profiles were similar among all e-waste open burning soil samples but differed from those in waste incinerator fly ash. The profiles and principal component analysis results suggested a unique mechanism of Cl-PAH and Br-PAH formation in EOBS. In addition, the Cl-PAHs and Br-PAHs showed high toxicities equivalent to PCDD/Fs measured in same EOBS samples when calculated based on their relative potencies to benzo[a]pyrene. Along with chlorinated and brominated dioxins and PAHs, Cl-PAHs and Br-PAHs are important environmental pollutants to investigate in EOBS.

Brominated flame retardants (BFRs) are widely used in consumer products. Their toxicological effects as endocrine disruptors have been partly examined. However, their immunological effects have not been elucidated. To evaluate the effects of BFRs on immune responses, we investigated whether BFRs affect phenotypes and the function of immune cells in vitro. Here we examined the commercial pentabromodiphenyl ether mixture (DE-71), octabromodiphenyl ether mixture (DE-79), decabromodiphenyl ether mixture (DE-83R), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Splenocytes and bone marrow (BM) cells were prepared from atopic prone NC/Nga mice. Splenocytes were exposed to each BFR for 24 h. BM cells were cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) for 8 days and BM-derived dendritic cells (BMDCs) were exposed to each BFR for 24 h. In another experiment, BM cells were cultured with GM-CSF in the presence of each BFR for 6 days during BMDC differentiation. After exposure, cell surface molecule expression and cytokine production were investigated. Each BFR increased MHC class II and CD86 expression and interleukin (IL)-4 production in splenocytes. DE-71, HBCD and TBBPA increased T cell receptor (TCR) expression in splenocytes. In both experiments, all BFRs except TBBPA increased DEC205 expression in BMDCs. BMDCs that differentiated in the presence of HBCD showed enhanced MHC class II, CD80, CD86 and CD11c expression. The results demonstrate that some BFRs may stimulate immune cells. BFRs can induce or enhance immune/allergic responses by increasing antigen presentation-related molecule expression and IL-4 production. Copyright © 2012 John Wiley & Sons, Ltd.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, and generate various types of PAH derivatives, such as nitrated PAHs, hydroxylated PAHs, and PAH quinones through chemical reactions in the atmosphere. PAHs are well known to activate the aryl hydrocarbon receptor (AhR), followed by the induction of metabolizing enzymes mainly in the liver, while biological responses to PAH derivatives are not understood well. In this study, we investigated the induction patterns of gene expression of CYP1 family and Phase II metabolizing enzymes in rat H4IIE cells exposed to PAH quinones and their parent PAHs for 24 h. Dibenz[a,h]anthracene and benzo[a]pyrene dramatically induced mRNA expression of CYP1 family, such as cytochrome P450 (Cyp) 1a1, Cyp1a2, and Cyp1b1, and PAH quinones, especially 1,4-chrysenequinone, possess a high potential to induce CYP1 family. As for Phase II enzymes, PAHs induced NAD(P)H: quinone oxidoreductase 1 (Nqo1) and UDP-glucuronosyltransferase (Ugt)1a6, and their i...

Polycyclic aromatic hydrocarbons (PAHs) and dioxins have several toxic properties, including mutagenicity, carcinogenicity and reproductive toxicity. PAHs mainly originate from the burning of petroleum and coal, while dioxins originate mainly from waste incineration and agrochemicals. Both PAHs and dioxins have aryl hydrocarbon receptor (AhR) binding activity which is related to toxicity of PAHs and dioxins. In this study, we evaluated AhR binding activity of airborne particles collected in Beijing, China and Kanazawa, Japan by DR-CALUX and the contribution of PAHs and dioxins to this activity. AhR binding activity of airborne particles in Beijing (1,200 ng • m-3) was four hundred times higher than in Kanazawa (2.7 ng • m-3). The composition of PAHs didn′t show large difference in Beijing and Kanazawa. The contribution of the PAHs to CALUX-TEQ was higher than dioxins and especially high in Kanazawa (10.4 %). These results suggest that PAHs show large contribution to the toxicity of airborne particles, and other kinds of PAH and PAH related compounds will also contribute to that toxicity. The difference of concentration and composition of these compounds result in the different level of toxicity of airborne particles in each city.

In our previous study, we demonstrated that dioxin-like activity in sulfuric-acid-treated extracts of Japanese indoor dust was higher than the activity in contaminated sediments. In the current study, we used high-performance liquid chromatography (HPLC) fractionation in combination with the dioxin-responsive chemical-activated luciferase gene expression (DR-CALUX) assay and gas chromatography-high-resolution mass spectrometry (GC-HRMS) to quantitatively evaluate dioxin-like compounds in indoor dusts. Selected four sulfuric-acid-treated extracts of indoor dusts were fractionated into seven fractions by means of HPLC with a nitrophenylpropylsilica column, and the activity in the first fraction of each extract was much higher than the activities in the other fractions. Therefore, each of the first fractions was further fractionated into 90 fractions by HPLC with an octadecylsilica column, and all the fractions were analyzed by means of the DR-CALUX assay. On the basis of elution characteristics, the active compounds in the fractions showing high activity were determined to be polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), coplanar polychlorinated biphenyls (Co-PCBs), and polychlorinated naphthalenes (PCNs), or supposed to be polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). These compounds in the 33 dusts extracts were quantified by means of GC-HRMS, and their median-based contributions of the theoretical CALUX-TEQs [2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD) equivalent] chemically calculated for PBDFs, PCDDs, PCDFs, non-ortho Co-PCBs, PCNs, and mono-ortho Co-PCBs to the experimental values (38-1400 pg/g, median 160 pg/g) were 17%, 14%, 8.8%, 0.98%, 0.10%, and 0.019%, respectively. Our results indicate that PBDFs, which are not internationally regulated dioxins, were important contributors to dioxin-like activity in Japanese dust and that further analysis of PBDFs in indoor dust is required so that the risk of exposure to these compounds via dust can be assessed.

We investigated soil pollution by chlorobenzenes (CBzs) and polychlorinated biphenyls (PCBs) in Bui Dau, a village in Vietnam known for informal electronic waste (e-waste) recycling activities. The total concentrations of CBzs and PCBs ranged from 17 to 1,400 ng/g and 2.0 to 7,200 ng/g, respectively, with the highest concentrations of the two compounds detected at e-waste open burning sites (EOBSs) in the survey area. The homologue profiles of CBzs and PCBs in the soils collected at the EOBSs were different from those in municipal solid waste incinerator (MSWI) fly ash. This result suggests that CBzs are formed from different processes during the open burning of e-waste and municipal solid waste incineration, even though both are combustion processes. The spatial distributions of CBzs and PCBs and the results of a multiple comparison test showed that these compounds were released from the EOBSs and spread around this survey area.

In Japan, water-quality monitoring with the environmental dioxin standard of 1 pg-TEQ/L at basic monitoring points set in a border between operation-area water and normal water is necessary for removal operations for bottom sediments containing dioxins. This paper presents a technique for combining on-site graphitic carbon (GrC) solid-phase extraction and bioassay method for the simplification and facilitation of water-quality monitoring. Using this method, we conducted experiments at an actual sediment removal site. Comparative analyses using high-resolution GC/MS (HRGC-HRMS) between the dioxin concentrations detected using a GrC solid-phase extraction kit and the official analytical method yielded similar concentrations and distributions of isomers for detected PCDD/Fs and DL-PCBs. The GrC solid-phase extraction method is inferred to have capacity equal to official analytical method extraction. Toxicity equivalent concentrations estimated using DR-CALUX correlate with equivalent concentrations with HRGC/HRMS. No false positive or false negative result was obtained for the standard value 1 pg-TEQ/L.

This study analyzed polyhalogenated compounds (PHCs) such as brominated flame retardants (BFRs) in indoor air and dust samples from two modern homes in Japan. Concentrations of polychlorinated biphenyls (PCBs) and 2,4,6-tribromophenol (2,4,6-TBP) in exhaust and indoor air of two houses were detected at 10(2)-10(3)pgm(-3) order, which were well above those in outdoor air. For dust samples, the detected polybrominated diphenyl ether (PBDE) and polybrominated dibenzo-p-dioxins/furan concentrations resembled values found in our past study. Interestingly, compared to PBDE concentrations, two orders of magnitude higher concentration (13000 ng g(-1)) was observed for hexabromocyclododecanes (HBCDs) in a dust sample from one house. Based on the calculation of air/dust partition ratio values (Kad), low Kad values (log Kad

To establish a concise and rapid procedure to analyze hexabromocyclododecane (HBCD) diastereomers in flame-retarded textiles, three different methods of extraction-Soxhlet, ultrasonic, and soaking extractions with toluene and dichloromethane (DCM)-were compared. During Soxhlet extraction using toluene, the percent contribution of alpha-HBCD to total HBCDs increased slightly and that of gamma-HBCD decreased, indicating that gamma-HBCD was isomerized to some extent at the boiling point of toluene (110.6 degrees C). For ultrasonic extraction, the temperature of the water bath can easily increase over time during the procedure, which might lead to undesirable effects. Therefore, we considered soaking extraction with DCM to be the most facile procedure to analyze HBCD diastereomers in textiles. Using the method established in this study, commercially available textiles in Japan (n=10) were analyzed to understand the actual composition of HBCD contents and its diastereomer profiles. With the exception of one textile sample, HBCDs were detected in all the samples analyzed, with concentrations ranging from 22000 to 43000 mg kg(-1) (i.e. 2.2-4.3%). We found a higher proportion of the alpha-diastereomer in most textile products compared with that of commercial HBCD mixtures, indicating that gamma-HBCD isomerized to alpha-diastereomer by heating processes to incorporate the commercial formulation into treated materials or that the alpha-diastereomer preferentially absorbed onto textile materials during the manufacturing of flame-retarded consumer products.

金沢大学医薬保健研究域薬学系, 金沢大学自然科学研究科, Several polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons (PAHs/NPAHs) such as benzo[a]pyrene and 1-nitropyrene are mutagens and/or carcinogens. These compounds secondarily generate PAH hydroxides, ketones, and quinones through atmospheric and metabolic reactions. The health effects of these compounds is now an important social concern. For example, lung cancer, bronchitis, whistling and so on. In this work, we evaluated toxicities of 25 PAH derivatives (hydroxides, ketones and quinones) in terms of aryl hydrocarbon receptor (AhR) binding and thyroid hormone-related endpoints using three in vitro bioassays: dioxinresponsive chemical-activated luciferase gene expression (DR-CALUX), thyroid receptor β chemical-activated luciferase gene expression (TRβ-CALUX), and competitive human transthyretin-binding (TTR-binding) assays. Eleven of the 25 PAH derivatives had AhR agonist activity, six had AhR antagonist activity and seven had TRpotentiation activity in the TR-CALUX. Furthermore, PAH quinones and hydroxides had strong TTR-binding activity. 3,4-Dihydrobenz[a]anthracen-1(2 H)-one had the strongest agonist activity (EC20: 0.4μM) as determined by DR-CALUX. PAH ketones showed stronger activity than the control and significant difference by statistical analysis. Benzo[c]phenanthrene-[1,4]-quinone was the most TTR-active compound (IC50: 2.5μM). Both PAH ketones and quinones, which have functional groups with low polarity, had significant activities in all tested assays. These in vitro results suggest that PAH derivatives might have various toxic activities in animals. For estimating the health effects and accessing the environmental risks of PAHs, further studies on the toxicity mechanisms are necessary. ©2009 The Pharmaceutical Society of Japan.

Photodebromination of technical decabromodiphenyl ether (DecaBDE) incorporated into high-impact polystyrene (HIPS) and TV casings was compared under natural sunlight conditions with that of technical decabromodiphenyl ethane (DeBDethane). BDE 209 in pulverized HIPS+DecaBDE samples degraded with a half-life of 51 days. In contrast, no marked loss of DeBDethane occurred throughout the experimental period of 224 days. During BDE 209 photolysis in HIPS+DecaBDE samples, partly debromination to nona- and octa-BDE was observed, however, environmentally relevant polybrominated diphenyl ether (PBDE) congeners such as BDE 47, 99, and 100 were not formed. Formation of polybrominated dibenzofurans (PBDFs) was clearly apparent in the flame-retarded plastics that we investigated. In the HIPS+DecaBDE samples, the PBDF concentration increased by about 40 times after 1 week of exposure, with a concomitant decrease in BDE 209. In the TV casing, tetra- to octa-BDF congener concentrations increased continuously during the experiment Although the concentrations of PBDFs found in the plastic matrices tested were 1 to 4 orders of magnitude lower than those of PBDEs, more attention should be paid to the fact that PBDFs are formed by sunlight exposure during normal use as well as disposal/recycling processes of flame-retarded consumer products.

Illegal dumping of polychlorinated biphenyl (PCB) capacitors was discovered in Kobe, Japan, in 2001, leaving about 68 m(3) (92 tons) of soil contaminated with approximately 6.6 kg of PCBs. Solvent extraction technology carried out in 2002-2003 using isopropyl alcohol remedied the affected soil at the site. Forty-seven batch treatments were conducted during full-scale treatment. On average, 8.4 extraction cycles per batch were needed to achieve the clean-up goal for PCBs (i.e., the Japanese environmental quality standard for soil). Analytical results showed that the average PCB concentration (88 microg g(-1)-dry soil) in untreated soil samples of all the batches was decreased to 1.2 microg g(-1)-dry soil in treated soil samples, yielding a removal efficiency of 98.6%. Dioxin responsive-chemical activated luciferase gene expression assay (DR-CALUX) and enzyme-linked immunosorbent assay (ELISA) adopting a monoclonal antibody against 2,3',4,4',5-pentachlorobiphenyl (PCB #118) were used to rapidly screen soil samples before and after solvent extraction. The DR-CALUX and ELISA results were in good agreement with World Health Organization toxicity equivalent values and analytically determined PCB concentrations, respectively. Regular monitoring during the treatment period confirmed that the applied technology met Japanese environmental and control regulations concerning treatment and disposal of contaminated soils and treatment residues. After full-scale treatment, the amount of PCBs recovered from the solvent purification system approximated the estimated amount of PCBs spilled.

In this paper, in order to provide a useful piece of information about inter-laboratory calibration study using in vitro bioassay in Japan and its evaluation method, outline and results of inter-laboratory calibration study for dioxins in food/feedstuff using DR-CALUX (Dioxin-Responsive Chemical-Activated LUciferase gene eXpression) assay with 21 participants were reported. The interlaboratory calibration study was divided into three phases. In Phase I, pure chemical mixtures consisted of PCDDs/PCDFs and Co-PCBs were analyzed. The TeCDD equivalents calculated using DR-CALUX assay (CALUX-TEQs) were equivalent to the theoretical CALUX-TEQs calculated chemically using concentrations of PCDDs/PCDFs and Co-PCBs and CALUX relative potencies to 2,3,7,8-TeCDD for these samples. Although lowest concentration sample indicated about 0.3 pM CALUX-TEQs per well, its reproducibility was comparatively good. During Phase II, cleaned sediment and food/feedstuff extracts prepared by organizer were analyzed. Decreases of interlaboratory reproducibility were observed with decrease of CALUX-TEQs in samples. In Phase II, samples indicating wide dispersion had low concentrations which were almost less than 0.3 pM CALUX-TEQs per well. In consideration of results for Phase I, although the limit of quantification for DR-CALUX assay was about 1 pM in general, 0.3 pM CALUX-TEQs per well might be the real limit of quantification. In Phase I and II, dispersion of data wasn't depending on a type of sample or dilution effect. In Phase III, whole fish oils and feedstuffs were extracted, cleaned, and analyzed by each participant according to protocol delivered by the organizer. The CALUX-TEQs were almost equivalent to the WHO-TEQs for these samples. Interlaboratory reproducibility tended to be higher than those during phase I and II. Increases of it were also observed with decrease of concentration in samples. The results demonstrated that the extraction and cleanup processes cause a major variation. From this study, it was indicated that Z-score provides useful information for identifying the cause of dispersion of data for each phase.

Four commercial oligomeric organophosphorus flame retardants (o-PFRs) were characterized using a refractive index detector and atmospheric pressure photoionization (APPI)-quadrupole time-of-flight mass spectrometry (QTOF-MS) compatible with gel permeation chromatography (GPC). Commercial o-PFRs consisted of approximately 90% or more oligomers and several impurities. Triphenyl phosphate (TPHP), tris(dimethylphenyl) phosphate (TDMPP), tris(2-chloroisopropyl) phosphate (TCIPP), and some new impurities were identified as byproducts of some manufacturing process of commercial o-PFRs for the first time. The concentrations of TPHP, TDMPP, and TCIPP were more than 1 weight %, whereas those of new impurities might be approximately 1 weight % by comparison among their abundances acquired through GPC-APPI-QTOF-MS analysis. Based on their vapor pressure and water solubility estimations, the potential environmental emissions of low molecular weight impurities were expected to be higher than those of oligomers. The presence and environmental emissions of low molecular weight impurities might be regarded as risk factors along with commercial o-PFRs.

Glucocorticoids (GCs) are widely used as anti-inflammatory drugs. Our previous study demonstrated that several GCs such as cortisol and dexamethasone (Dex) were frequently detected in effluents collected from Japanese sewage treatment plants (STPs) in 2012. In this study, we used the GC-Responsive Chemical-Activated LUciferase gene eXpression (GR-CALUX) assay to elucidate GC receptor (GR) agonistic activities of ten pure synthetic GCs and selected STP effluents in Japan for assessment of the risks associated with the presence of GR agonists. The tested GCs demonstrated dose-dependent agonistic effects in the GR-CALUX assay and their EC 50 values were calculated for estimation of relative potencies (REPs) compared to Dex. The GR agonistic potency was in the rank of: clobetasol propionate > clobetasone butyrate > betamethasone 17-valerate > difluprednate > betamethasone 17,21-dipropionate > Dex > betamethasone > 6α-methylprednisolone > prednisolone > cortisol. The GR agonistic activity in STP effluents as measured in Dex-equivalent (Dex-EQ) activities ranged from − 1 (median: 29 ng L − 1 , n = 50). To evaluate the contribution of the target GCs, theoretical Dex-EQs were calculated by multiplying the concentrations of each GC by its respective REP. Our calculation of Dex-EQ contribution for individual GR agonists indicated that the well-known GCs cortisol and Dex should not be given priority for subsequent in vivo testing, monitoring and removal experiments, but rather the highly potent synthetic GCs clobetasol propionate and betamethasone 17-valerate (REP = 28 and 3.1) as well as other unidentified compounds are important GR agonists in STP effluents in Japan.

Animal bedding made of waste wood samples from seven different plants in Japan were chemically analyzed in terms of persistent organic pollutants (POPs) including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs), coplanar polychlorinated biphenyls (Co-PCBs), drin compounds, chlordane compounds and various inorganic toxic compounds (Cr, Cu, As, B, Cd and Pb) to investigate the chemical characteristics and levels of contamination. Further investigation was conducted to determine the success of applying the Chemically Activated Luciferase Expression (CALUX) bioassay to the waste wood samples in combination with a cleanup procedure for the detection of dioxin-like compounds in order to develop the CALUX bioassay as a rapid and cost-effective screening/monitoring method and a contributive tool to risk management in the waste wood recycling process. For the cleanup procedure, crude extracts from wood samples were prepared by dimethylsulfoxide (DMSO)/n-hexane extraction, and then the extracts were processed by silica gel–44% sulfuric acid reflux treatment at 70 °C for 60 min to yield the bioassay fractions.The presence of POPs and inorganic toxic compounds were confirmed in most of the litter samples. In particular, Co-PCBs in one sample (litter dust) showed a high concentration level (1,200,000 pg/g, 240 pg TEQ/g), suggesting the potential for contamination from demolition waste.The CALUX assay-determined TEQs (CALUX-TEQs) were significantly high in the sample after DMSO/n-hexane extraction, probably due to labile aryl hydrocarbon receptor (AhR) ligands such as PAHs; however, they were remarkably reduced through a single silica gel–44% sulfuric acid reflux treatment. The ratio between CALUX-TEQ values and WHO toxicity equivalent values (WHO-TEQ) obtained by congener-specific chemical analysis ranged from 0.058 to 22 and show comparatively good agreement. Underestimation in some samples, however, was observed where WHO-TEQ values of Co-PCBs contributed greatly to total WHO-TEQ values. Reasons for this gap could be lower CALUX assay-determined relative potencies (REPs) than the WHO-TEFs for these congeners or AhR-antagonistic effects of non dioxin-like PCBs which coexist at higher concentration than Co-PCBs. The CALUX assay is proposed as a promising application in the recycling process of wooden materials. Keywords: Wood, CALUX, Persistent organic pollutants

ハロゲン化芳香族炭化水素化合物 (PHAHs: Polyhalogenated aromatic hydrocarbons) による様々な毒性および生物学的反応の多くはアリル炭化水素受容体 (AhR: aryl hydrocarbon recepter) を介することが知られている。EROD (ethoxyresorufin-O-deethylase) およびCALUX (chemical-activated luciferase gene expression) バイオアッセイはPHAHsによるAhRを介した遺伝子発現反応を利用した感度の高い生物学的測定法であり, 未知物質も含め, 環境・廃棄物試料のような混合物中に含まれるダイオキシン様活性物質を包括的に検出することができる。ダイオキシン様物質を検出するためのAh結合バイオアッセイについて, 培養細胞によるEROD法およびCALUX法を中心に, 背景, 歴史, イムノアッセイとの比較, ハロゲン化芳香族炭化水素化合物, および環境・廃棄物試料への分析応用例等について概説した。ERODまたはCALUXバイオアッセイをGC/MSによる個別定量と併用すること, あるいは化学分析前のプレスクリーニングに用いることにより, 環境・廃棄物試料などに含有されるダイオキシン様物質を包括的に理解するうえで有用と考えられる。

The yeast estrogen screen was applied to sewage treatment process waters to identify the presence of estrogenic activity and to investigate the fate and behavior of estrogenic substances through treatment. Hydrophobic fractions in the water phase were extracted and concentrated using C18 cartridges for the effective extraction of 17β-estradiol (E2) and other estrogen mimics. Clear dose-dependent elevation in the synthesis of β-galactosidase in the yeast screen was observed with all the samples tested, demonstrating that these samples were estrogenic. However, estrogenic activity tended to reduce during the treatment, especiallyiin the biological process. Quantification results of the yeast estrogen screen in terms of E2 equivalent were compared with actual E2 concentrations measured by an ELISA. E2 occupied 34% of the whole estrogenicity in the raw sewage, while almost 100% in the final effluent. The analyses of the sewage treatment process waters revealed that human estrogens are major causative substances in terms of estrogenic activity in sewage and its treated effluent. Although findings of possible correlation of environmental estrogens with the real impact on human health and the ecosystem are still the focus of scientific debate and investigation, proper management should be established in the sewage treatment process which receives various environmental contaminants.

Four advanced sewage treatments (sand filtration, ozone/hydrogen peroxide treatment (AOP), microfiltration (MF), and reverse osmosis (RO)) were compared in terms of their capability to reduce estrogenicity, genotoxicity, and acute toxicity, assuming portable reuse of the effluents. Yeast estrogen screening and an enzyme-linked immunosorbent assay indicated that both overall estrogenicity and 17β-estradiol concentration were significantly reduced by RO and AOP (removals more than 97 % were achieved) while sand filtration and MF were not sufficient. This tendency of similar toxicity levels for RO and AOP effluents, was consistent with genotoxicity and mutagenicity results for Ames test, umu test, and B. subtilis rec-assay and acute toxicity (Microtox®). However, a different trend was observed for total organic carbon (TOC) removal (i.e., higher removal by RO than AOP). This implies that AOP is capable of reducing the toxicity even if TOC is not completely mineralized. Results show that AOP and RO are much m...

To investigate the formation of mobile organic plutonium, we analyzed the plutonium contents of the fulvic (FA) and humic (HA) acids from the soil samples obtained at Nishiyama, Nagasaki, Japan. The percentages of the plutonium bound strongly to HA and to FA vs. the total plutonium in the soil were 5–10% and 1%, respectively, at the depth of 0–0.1 m, much higher values than those of137Cs and uranium. After being weathered for 51 years under a temperate climate, the initial highfired oxides of fallout plutonium have become as chemically reactive plutonium from nuclear fuel reprocessing plants.

One of the most visible tragedies by industrial water pollution is Minamata disease, methylmercury poisoning caused by eating contaminated fish, which has killed more than 100 people and paralyzed several thousand people around Minamata Bay, Japan and the adjacent Yatsushiro Sea since 1956. The cause of Minamata disease was confirmed, not by analyzing environmental samples such as sediments (containing more than 600 ppm of Hg) or fish (at least 20 ppm) at the bay, but by symptoms of Minamata disease patients that resembled previous mercury poisoning reported in a European medical journal. Mercury dispersion was traced for 22 years to collect mercury concentration measurements in Yatsushiro Sea surface sediments at 24 fixed stations. The analytical results of mercury revealed four trends of mercury movement from the bay: 1) a rapid increase in Hg concentrations up to 1984; 2) a dramatic decrease in mercury concentrations after an artificial mercury decontamination project began in 1984; 3) a strange drop in mercury contents due to an historical rainfall in the region in 1982 and; 4) natural decontamination, which has been underway since 1985. The tragedy at Minamata has provided many lessons which have shaped the scientific field in environmental research, especially in the area of water quality.

都市下水の終末処理場の活性汚泥処理槽前後の水試料についてXAD-2を用いた濃縮をおこない, その後フミン酸添加および無添加の条件で枯草菌 Rec-assay に適用した. その結果, フミン酸添加は流入水にはDNA損傷性緩和効果がみられなかったが, 流出水はフミン酸添加濃度が高くなるにつれDNA損傷性がわずかに緩和された. 次に, 3種のDNA損傷性物質に対しフミン酸添加および無添加におけるXAD-2による回収率についても比較検討したが, 有意な差はみられなかった. さらに, その3物質をフミン酸添加および無添加の条件で枯草菌 Rec-assay に適用したところ, 疎水性の高い Pyrene や Benzo(a)pyrene のDNA損傷性は大きく緩和されたが, アミノ基を有する比較的親水性の高い 1-Aminopyrene には緩和効果は小さかった.

Hexabromocyclododecanes (HBCDs) have been used for flame retardation mainly in expanded polystyrene (EPS) and extruded polystyrene (XPS) insulation foams. Controlled incineration experiments with solid wastes containing each of EPS and XPS were conducted using a pilot-scale incinerator to investigate the destruction behavior of HBCDs and their influence on the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs). EPS and XPS materials were respectively blended with refuse derived fuel (RDF) as input wastes for incineration. Concentrations of HBCDs contained in the EPS- and XPS-added RDFs, were 140 and 1100 mg kg(-1), respectively. In which γ-HBCD was dominant (68% of the total HBCD content) in EPS-added RDF and α-HBCD accounted for 73% of the total HBCDs in XPS-added RDF. During the incineration experiments with EPS and XPS, primary and secondary combustion zones were maintained at temperatures of 840 °C and 900 °C. The residence times of waste in the primary combustion zone and flue gas in the secondary combustion zone was 30 min and three seconds, respectively. HBCDs were steadily degraded in the combustion chambers and α-, β-, and γ-HBCD behaved similarly. Concentration levels of the total HBCDs in the bag filter exit gas for the two experiments with EPS and XPS were 0.7 and 0.6ngmN(-3), respectively. HBCDs were also not detected (

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in consumer products. Humans can be exposed to PBDEs mainly through the inhalation of air or dust. Thus, PBDEs can affect respiratory and immune systems. In the present study, we investigated whether PBDEs stimulate bronchial epithelial cells. We examined commercial penta-BDE (DE-71), octa-BDE (DE-79), and deca-BDE (DE-83R). Human bronchial epithelial cells (BEAS-2B) were exposed to each PBDE for 24h. Subsequently, the expression of intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines were investigated. DE-71 and DE-79, but not DE-83R, significantly increased the expression of ICAM-1, interleukin-6 (IL-6), and IL-8 in BEAS-2B. Because these remarkable effects were observed with DE-71, we further investigated the underlying intracellular mechanisms. DE-71 promoted epidermal growth factor receptor (EGFR) phosphorylation. Inhibitors of EGFR-selective tyrosine kinase and p38 mitogen-activated protein kinase effectively blocked the increase of IL-6 and IL-8. Furthermore, antagonists of thyroid hormone receptor and aryl hydrocarbon receptor significantly suppressed the increase in IL-6 and/or IL-8 production. In conclusion, penta- and octa-BDE, but not deca-BDE, might promote the expression of proinflammatory proteins in bronchial epithelial cells possibly by activating protein kinases and/or stimulating nuclear receptors related to subsequent activation of transcriptional factors.