Spatial distribution and benthic risk assessment of cyclic, linear, and modified methylsiloxanes in sediments from Tokyo Bay catchment basin, Japan: Si-based mass profiles in extractable organosilicon.

We investigated the spatial distribution, mass profiles, and benthic risk assessment of a wide range of methylsiloxanes (MSs), including 7 cyclic MSs (CMSs; D3-D9; the number refers to the number of SiO bonds), 13 linear MSs (LMSs; L3-L15), and 15 modified and other MSs (MMSs) in sediments from the Tokyo Bay catchment basin, Japan. We observed widespread distribution of MSs (ΣCMS, ΣLMS, and ΣMMS) in the sediment samples, with concentrations of 1.0-6180 ng/g dry weight (dw), 1.

Spatial distribution and accumulation profiles of volatile methylsiloxanes in Tokyo Bay, Japan: Mass loadings and historical trends.

We investigated mass loading and the spatial distribution of volatile methylsiloxanes (VMSs) including four cyclic VMSs (D3-D6; cVMSs, the number refers to the number of SiO bonds) and three linear VMSs (L3-L5; lVMSs) in Tokyo Bay, Japan, which is one of the most industrialized, urbanized, and populated areas in the world. Based on the VMS concentrations determined in eight main inflow rivers to the bay, the mass loading of VMSs via inflow rivers and sewage treatment plants located in Tokyo Bay was estimated at 2500 kg/y for total VMSs. Elevated mass loadings of VMSs were found in three of the rivers, inflowing to the inner west of Tokyo Bay.

Distribution characteristics of methylsiloxanes in atmospheric environment of Saitama, Japan: Diurnal and seasonal variations and emission source apportionment.

The large production volume of methylsiloxanes (MSs), combined with their high mobility/volatility and persistence, is a matter of concern from the atmospheric pollution perspective. Therefore, we evaluated of the concentrations and emission sources of MSs, including 7 cyclic methylsiloxanes (D3-D9; CMSs, the number refers to the number of Si-O bonds) and 13 linear methylsiloxanes (L3-L15; LMSs) in ambient air collected from Saitama, Japan. This is a first study regarding the evaluation of 20 methylsiloxanes in the Japanese atmosphere.

Volatile methylsiloxanes in sewage treatment plants in Saitama, Japan: Mass distribution and emissions.

Wastewater, aeration gas, dewatered sludge, and incineration ash and flue gas (from dewatered sludge) were collected from 9 sewage treatment plants (STPs) located in Saitama Prefecture, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs) namely, D3, D4, D5, D6, L3, L4, and L5. The mass loadings and distribution of VMSs in STPs were estimated based on measured concentrations in liquid, solid, and gaseous samples, including incinerated dewatered sludge. Mass loading of ΣVMS varied widely from 21 kg y to 3740 kg y, depending on the volume of wastewater treated in each STP.

Accumulation of quaternary ammonium compounds as emerging contaminants in sediments collected from the Pearl River Estuary, China and Tokyo Bay, Japan.

In this work, the distribution of quaternary ammonium compounds (QACs) in two dated sediment cores, collected from the Pearl River Estuary (PRE) and Tokyo Bay (TB), were investigated to understand the historical input of QACs and their diagenetic behavior in urban estuarine environments. The vertical variation profiles of QAC concentrations showed that benzylalkyldimethyl ammonium compounds (BACs) and dialkyldimethyl ammonium compounds (DADMACs) were widely used during 1970s and 1980s both in China and Japan. The declining environmental concentrations of QACs suggested a compositional change of commodities and the effectiveness of emission control strategies.

Effects of characteristics of waste incinerator on emission rate of halogenated polycyclic aromatic hydrocarbon into environments.

We determined the concentrations of halogenated polycyclic aromatic hydrocarbons (XPAHs), some of which are carcinogenic and/or mutagenic compounds, in fly and bottom ashes and stack gas collected from waste incinerators in Japan. The dominant XPAHs in stack gas were consistent with those in the urban atmosphere. The dioxin-like toxic equivalent (TEQ) concentration ranges of the XPAHs in stack gas, fly ash, and bottom ash were 0.

Rate of hexabromocyclododecane decomposition and production of brominated polycyclic aromatic hydrocarbons during combustion in a pilot-scale incinerator.

Here, we examined the incineration of extruded polystyrene containing hexabromocyclododecane (HBCD) in a pilot-scale incinerator under various combustion temperatures (800-950°C) and flue gas residence times (2-8sec). Rates of HBCD decomposition ranged from 99.996% (800°C, 2sec) to 99.

Mechanism of Formation of Chlorinated Pyrene during Combustion of Polyvinyl Chloride.

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are an emerging class of environmental contaminants, but the sources of these chemicals in the environment are not well-known. In this study, we developed a kinetic model describing the chlorination of PAHs to elucidate the mechanism of formation of ClPAHs during the combustion of organic waste containing chlorinated compounds and/or chlorine in an incinerator. Pyrene (Pyr) and polyvinyl chloride (PVC) were selected as a model PAH and a model organic substrate, respectively.

Spatial distribution and exposure risks of ambient chlorinated polycyclic aromatic hydrocarbons in Tokyo Bay area and network approach to source impacts.

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) receive increasing attention as hazardous pollutants in terms of the high environmental persistence and toxicities. Ambient concentrations of 24 ClPAHs and 24 PAHs were investigated at 14 sites in the Tokyo Bay area of Japan. Twelve of 18 ClPAH species were detected in air samples, in spite of small sampling volumes.

Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method.

Occurrence, profiles, and toxic equivalents of chlorinated and brominated polycyclic aromatic hydrocarbons in E-waste open burning soils.

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.

Spatial and temporal trends of short- and medium-chain chlorinated paraffins in sediments off the urbanized coastal zones in China and Japan: A comparison study.

To examine the impacts of urbanization and industrialization on the coastal environment, and assess the effectiveness of control measures on the contamination by chlorinated paraffins (CPs) in East Asia, surface and core sediments were sampled from the urbanized coastal zones in China and Japan (i.e., Pearl River Delta (PRD), Hong Kong waters and Tokyo Bay) and analyzed for short-chain (SCCPs) and medium-chain CPs (MCCPs).

Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method.

Surface waters including river water and effluent from sewage treatment plants (STPs) were collected from Tokyo Bay watershed, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs), i.e., D3, D4, D5, D6, L3, L4, and L5 by an optimized purge and trap extraction method.

Airborne PM2.5/PM10-associated chlorinated polycyclic aromatic hydrocarbons and their parent compounds in a suburban area in Shanghai, China.

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have been reported to be formed during incineration processes. Despite dioxin-like toxicities of ClPAHs, little is known on the occurrence of these chemicals in the environment. In this study, concentrations of 24-h airborne PM10 and PM2.

Does wet precipitation represent local and regional atmospheric transportation by perfluorinated alkyl substances?

Perfluorinated alkyl substances (PFASs) have been found widely in the environment including remote marine locations. The mode of transport of PFASs to remote marine locations is a subject of considerable scientific interest. Assessment of distribution of PFASs in wet precipitation samples (i.

Transport of perfluoroalkyl substances (PFAS) from an arctic glacier to downstream locations: implications for sources.

Perfluoroalkyl substances (PFAS) have been globally detected in various environmental matrices, yet their fate and transport to the Arctic is still unclear, especially for the European Arctic. In this study, concentrations of 17 PFAS were quantified in two ice cores (n=26), surface snow (n=9) and surface water samples (n=14) collected along a spatial gradient in Svalbard, Norway. Concentrations of selected ions (Na(+), SO4(2-), etc.

Levels and sources of planar and non-planar PCBs in pine needles across Poland.

Under a small project, one-year-old Scots Pine needles collected from 25 spatially distant sites were examined in monitoring the extent of environmental diffusion and possible sources of polychlorinated biphenyls (PCBs) in ambient air, their depositions and uptake by plants in Poland. The congener-specific determination of planar and non-planar chlorobiphenyls was achieved by isotope dilution HRGC-HRMS method after a highly refined extraction on multi-layer column of silica gel and alumina layer and clean-up, and fractionations, followed by Hypercarb-HPLC and PYE-HPLC sub-fractionation steps. Contents of 117 chlorobiphenyls determined in pine needles varied for the 25 sites studied and is between 2.

Distribution, characteristics, and worldwide inventory of dioxins in kaolin ball clays.

Distribution, characteristics, and global inventory of dioxins (polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs] and dioxin like polychlorinated biphenyls) in kaolin clays collected from 10 countries were investigated. Dioxins were found in all kaolin clay samples analyzed, at total concentrations ranging from 1.2 pg/g (Brazil) to 520,000 pg/g (USA).

Profiles of nonylphenol isomers in surface waters from Sri Lanka.

Isomer-specific concentrations of nonylphenol (NP) and their predicted estrogenic potency were investigated in Sri Lankan waters for the first time. The total concentration of 13 NP isomers ranged from 90 to 1835 ng/L, while the predicted estrogenic equivalent concentration ranged from 0.072 to 1.

Environmental analysis of chlorinated and brominated polycyclic aromatic hydrocarbons by comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry.

A method for the analysis of chlorinated and brominated polycyclic aromatic hydrocarbon (Cl-/Br-PAHs) congeners in environmental samples, such as a soil extract, by comprehensive two-dimensional gas chromatography coupled to a high resolution time-of-flight mass spectrometry (GC×GC-HRTOF-MS) is described. The GC×GC-HRTOF-MS method allowed highly selective group type analysis in the two-dimensional (2D) mass chromatograms with a very narrow mass window (e.g.

Mechanisms of olfactory toxicity of the herbicide 2,6-dichlorobenzonitrile: essential roles of CYP2A5 and target-tissue metabolic activation.

The herbicide 2,6-dichlorobenzonitril (DCBN) is a potent and tissue-specific toxicant to the olfactory mucosa (OM). The toxicity of DCBN is mediated by cytochrome P450 (P450)-catalyzed bioactivation; however, it is not known whether target-tissue metabolic activation is essential for toxicity. CYP2A5, expressed abundantly in both liver and OM, was previously found to be one of the P450 enzymes active in DCBN bioactivation in vitro.

Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, and naphthalenes in plasma of workers deployed at the World Trade Center after the collapse.

Blood plasma samples (n = 43) collected retrospectively from New York State employees and National Guard personnel who had been assigned to work in the vicinity of the World Trade Center (WTC) during the week after the collapse of the buildings were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). On the basis of algorithms developed to rank individual exposures to dust and debris and to smoke, we categorized the samples as: more smoke exposure (MSE), more dust exposure (MDE), less smoke exposure (LSE), and less dust exposure (LDE). Mean concentrations of PCDDs were 1070, 223, 3690, and 732 pg/g lipid wt, and mean concentrations of PCDFs were 910, 1520, 230, and 117 pg/g lipid wt, for the MSE, MDE, LSE, and LDE groups, respectively.

Partitioning behavior of per- and polyfluoroalkyl compounds between pore water and sediment in two sediment cores from Tokyo Bay, Japan.

The partitioning behavior of per- and polyfluoroalkyl compounds (PFCs) between pore water and sediment in two sediment cores collected from Tokyo Bay, Japan, was investigated. In addition, the fluxes and temporal trends in one dated sediment core were studied. Short-chain perfluoroalkyl carboxylic acids (PFCAs) (C < or = 7) were found exclusively in pore water, while long-chain PFCAs (C > or = 11) were found only in sediment The perfluoroalkyl sulfonates (PFSAs), n-ethylperfluoro-1-octanesulfonamidoacetic acid (N-EtFOSAA), and perfluorooctane sulfonamide (PFOSA) seemed to bind more strongly to sediment than PFCAs.

Polybrominated diphenyl ethers, polychlorinated naphthalenes and polycyclic musks in human fat from Italy: comparison to polychlorinated biphenyls and organochlorine pesticides.

Prior to this study, reports of occurrence of polycyclic musks and polychlorinated naphthalenes (PCNs) in human tissues from Italy were not available. In this study, concentrations of PCNs and polycyclic musks were determined in human adipose tissue from Italy collected during 2005-2006; for comparison, legacy organohalogen pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined. SigmaPCN concentrations ranged from 0.