细化搜索
结果 41-50 的 61
The New Jersey Toxics Reduction Workplan for Ny-Nj Harbor: Distribution of Pcdd/Fs in Ambient Waters
2006
Dimou, K Nadia | Pecchioli, Joel A
As part of the NJ Toxics Reduction Workplan for NY-NJ Harbor, ambient water samples were collected at fifteen locations along the tidal portions of the Hackensack, Passaic, Raritan, Rahway and Elizabeth Rivers, and in Newark Bay, the Arthur Kill, and Kill van Kull. A Trace Organics Platform Sampler was used to collect a total of 75 suspended sediment phase samples between June 2000 and May 2002. These samples were analyzed for spatial and wet vs. dry weather trends in the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs; modified USEPA Method 1613b). Mean total PCDD/F (tPCDD/F) concentrations at the sampling locations ranged between 3.8 and 41.5 ng/g. On average, OCDD accounted for almost 80% of the tPCDD/F concentrations; mean total [PCDD/F - OCDD] concentrations ranged between 0.84 and 5.20 ng/g at the sampling locations. Mean 2,3,7,8-TCDD concentrations ranged between 0.003 and 0.28 ng/g, with the highest concentrations (> 0.10 ng/g) along the tidal Passaic and lower Hackensack Rivers, and in upper Newark Bay. Mean tPCDD/F Toxic Equivalency Quotients (TEQ) ranged between 45 and 344 TEQ pg/g, with the highest levels found in the lower Passaic River. Toxicity was primarily driven by 2,3,7,8-TCDD concentrations in the Passaic and Hackensack Rivers, and in Newark Bay. Examples of congener distribution patterns at some of the sampling locations are also presented.
显示更多 [+] 显示较少 [-]Organochlorines and other environmental contaminants in muscle tissues of sportfish collected from San Francisco Bay
1997
Fairey, R. | Taberski, K. | Lamerdin, S. | Johnson, E. | Clark, R.P. | Downing, J.W. | Newman, J. | Petreas, M. (Moss Landing Marine Laboratories, Moss Landing, CA 95039 (USA))
Influence of dioxin exposure upon levels of prostate-specific antigen and steroid hormones in Vietnamese men
2016
Sun, Xian Liang | Kido, Teruhiko | Honma, Seijiro | Okamoto, Rie | Manh, Ho Dung | Maruzeni, Shoko | Nishijo, Muneko | Nakagawa, Hideaki | Nakano, Takeshi | Koh, Eitetsu | Takasuga, Takumi | Nhu, Dang Duc | Hung, Nguyen Ngoc | Lê, Kế Sơn
Most studies on the relationship between Agent Orange and prostate cancer have focused on US veterans of the Vietnam War. There have been few studies focusing on the relationship between levels of prostate-specific antigen (PSA) and dioxins or steroid hormones in Vietnamese men. In 2009–2011, we collected blood samples from 97 men who had resided in a “dioxin hotspot” and 85 men from a non-sprayed region in Vietnam. Then levels of PSA, dioxins, and steroid hormones were analyzed. Levels of most dioxins, furans, and non-ortho polychlorinated biphenyls were higher in the hotspot than those in the non-sprayed region. Levels of testosterone, dehydroepiandrosterone, and estradiol differed significantly between the hotspot and the non-sprayed region, but there were no correlations between levels of PSA and steroid hormones and dioxins in either of the two regions. Our findings suggest that PSA levels in Vietnamese men are not associated with levels of dioxin or steroid hormones in these two regions.
显示更多 [+] 显示较少 [-]Dioxins in the semen of men with infertility
2015
Galimova, E. F. | Amirova, Z. K. | Galimov, Sh. N.
The purpose of the present study was to assess ejaculate contamination by polychlorinated dibenzo-p-dioxins/furans in male infertility. The database of 168 infertile and 49 fertile men was included in the study. Dioxin content was determined using gas chromatography/high-resolution mass spectrometry (GC/HRMS). In the ejaculate of infertile men, the content of dioxins and furans was 2.2–2.3 times higher than in fertile donors. The maximum level of the most toxic dioxin congener was detected in pathospermia. Contamination of semen of infertile men by polychlorinated dibenzo-p-dioxins/furans supports the hypothesis about the relationship between environmental factors and reproductive health.
显示更多 [+] 显示较少 [-]Photochemistry of tetra- through hexa-brominated dioxins/furans, hydroxylated and native BDEs in different media
2015
Roszko, Marek | Szymczyk, Krystyna | Jędrzejczak, Renata
The aim of this study was to investigate (i) the behavior of native PBDEs during UV irradiation in different media, (ii) the possibility of their transformation into hydroxylated PBDEs in aqueous media, and (iii) the photochemistry/levels of brominated dioxins/furans formed from hydroxylated PBDEs. Debromination leading to the formation of a wide range of low-brominated congeners was the main path of photocatalyzed transformations of PBDEs. In organic solvents other than toluene, BDEs degraded in line with the pseudo first order kinetics (10–20 min half-life, depending on congener type and reaction medium). Irradiated BDE 209 congener behaved quite differently than lower-brominated BDEs: detectable amounts of various bromo-benzenes were found. That suggests that UV irradiation of BDE 209 leads to cleavage of the ether bound between the congener’s aromatic rings. Formation of bromophenyl bromo-methyl-biphenyl ethers or benzyl-bromophenoxybenzenes was observed in irradiated PBDE toluene-based solutions. The total concentration of OH-BDEs found in the reaction medium did not exceed 0.2 % of the initial precursor mass. Moreover, lower-brominated congeners detected in the reaction medium indicate subsequent debromination of OH-BDEs or hydro-debromination of the degraded congeners. Brominated dioxins and low levels of furans were observed in samples containing OH-BDEs. The total mass of dioxins did not exceed 3.5 % of the initial precursor mass.
显示更多 [+] 显示较少 [-]Persistent organic pollutants in the atmosphere from urban and industrial environments in the Rhine Valley: PCBs, PCDD/Fs
2013
Guéguen, Florence | Stille, Peter | Millet, Maurice
Polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxin and furan (PCDD/F) concentrations in the atmosphere were analysed using passive air samplers (PAS) close to the Rhine River between France and Germany. Collectors were placed in industrial, urban, rural and remote areas (Vosges Mountains) between March 2009 and August 2010, and the mean PCB concentrations (sum of 22 congeners) were 3.3, 3.9, 4.1 and 1.4 ng PAS⁻¹ day⁻¹, respectively. Two events during the sampling period were observed in April 2009 and February–March 2010 with the highest PCB concentrations found in the industrial area (19.6 ng PAS⁻¹ day⁻¹). PCDD/F level were measured during these periods, and the maximum concentration observed was from 37.5 fg WHO PAS⁻¹ day⁻¹
显示更多 [+] 显示较少 [-]Obsolete pesticide storage sites and their POP release into the environment—an Armenian case study
2012
Dvorská, A. | Šír, M. | Honzajková, Z. | Komprda, J. | Čupr, P. | Petrlík, J. | Anakhasyan, E. | Simonyan, L. | Kubal, M.
Organochlorinated pesticides were widely applied in Armenia until the 1980s, like in all former Soviet Union republics. Subsequently, the problem of areas contaminated by organochlorinated pesticides emerged. Environmental, waste and food samples at one pesticide burial site (Nubarashen) and three former pesticide storage sites (Jrarat, Echmiadzin and Masis) were taken and analysed on the content of organochlorinated pesticides, polychlorinated dibenzo-p-dioxins and furans and dioxin-like polychlorinated biphenyls. Gradient sampling and diffusivity-based calculations provided information on the contamination release from the hot spots on a local scale. A risk analysis based on samples of locally produced food items characterised the impact of storage sites on the health of nearby residents. All four sites were found to be seriously contaminated. High pesticide levels and soil and air contamination gradients of several orders of magnitude were confirmed outside the fence of the Nubarashen burial site, confirming pesticide release. A storage in Jrarat, which was completely demolished in 1996 and contained numerous damaged bags with pure pesticides until 2011, was found to have polluted surrounding soils by wind dispersion of pesticide powders and air by significant evaporation of lindane and β-endosulfan during this period. Dichlorodiphenyltrichloroethane-contaminated eggs, sampled from hens roaming freely in the immediate surroundings of the Echmiadzin storage site, revealed a significant health risk for egg consumers above 1E−5. Although small in size and previously almost unknown to the public, storage sites like Echmiadzin, Masis and Jrarat were found to stock considerable amounts of obsolete pesticides and have a significant negative influence on the environment and human health. Multi-stakeholder cooperation proved to be successful in identifying such sites suspected to be significant sources of persistent organic pollutants.
显示更多 [+] 显示较少 [-]The war in Kosovo : Evidence of pollution transport in the Balkans during operation “Allied Force”
2000
Melas, Dimitrios | Zerefos, Christos | Rapsomanikis, Spyros | Tsangas, Nikolaos | Alexandropoulou, Alexandra
During the operation “Allied Force” in the spring of 1999, the burning or damaging of industrial and military targets in the Former Republic of Yugoslavia resulted in the release of a large number of chemicals into the atmosphere. The releases contained not only conventional air pollutants, but also Semi-Volatile Organic compounds (SVOs) which are known to be hazardous to health. Under suitable meteorological conditions, these chemicals can be transported across borders over large distances. In this paper, an analysis of measurements and dispersion calculations is presented which provides evidence of pollutant transport from the conflict area to Greece. The measuring program was carried out in Xanthi, Greece and included aerosol sampling and subsequent analysis for the determination of the concentration of SVOs including dioxins, furans, PCBs (PolyChlorinated Biphenyls), PAHs (Polycyclic Aromatic Hydrocarbons) and organic phthalates.This paper focuses on two episodes of organic phthalates that were observed during the conflict period. Pollution measurements are interpreted by means of air trajectories and dispersion calculations. For this purpose, the HYSPLIT_4 (HYbrid Single-Particle Langrangian Integrated Trajectory) modeling system is used to calculate the dispersion of toxic substances.
显示更多 [+] 显示较少 [-]Analytical characterization of products obtained from slow pyrolysis of Calophyllum inophyllum seed cake: study on performance and emission characteristics of direct injection diesel engine fuelled with bio-oil blends
2018
Sakthivel, R. (Rajamohan) | Kasimani, Ramesh
This paper aims to analyse the characteristics and properties of the fractions obtained from slow pyrolysis of non-edible seed cake of Calophyllum inophyllum (CI). The gas, bio-oil and biochar obtained from the pyrolysis carried out at 500 °C in a fixed bed batch type reactor at a heating rate of 30 °C/min were characterized by various analytical techniques. Owing to the high volatile content of CI biomass (72.61%), it was selected as the raw material in this present investigation. GC-MS and FT-IR analysis of bio-oil showed the presence of higher amount of oxygenated compounds, phenol derivatives, esters, acid and furans. The physicochemical properties of the bio-oil were tested as per ASTM norms which imply that bio-oil is a highly viscous liquid with lower heating value as compared to that of diesel fuel. The chemical composition of evolved gas was analysed by using GC testing which revealed the presence of combustible components. The FT-IR characterization of biochar showed the presence of aliphatic and aromatic hydrocarbons whereas the elevated amount of carbon in biochar indicates its potential to be used as solid fuel. The performance and emission characteristics of CI engine were assessed with different CI bio-oil blends and compared with baseline diesel fuel. The results showed that addition of bio-oil leads to decreased brake thermal efficiency and increased brake specific energy consumption. Meanwhile, increase in blend ratio reduces harmful pollutants such as oxides of nitrogen and smoke in the exhaust. From the engine testing, it is suggested to employ 20% of CI bio-oil blends in CI engine to obtain better operation.
显示更多 [+] 显示较少 [-]Thermal decomposition of municipal solid waste fly ash and desorption of polychlorinated dibenzo-p-dioxins and furans from fly ash surfaces
2016
Weidemann, Eva | Lundin, Lisa | Boily, Jean-François
Surfaces of fly ashes from three Swedish MSW incinerating plants were extensively characterized to better predict their involvement in the generation of persistent organic pollutants. The ashes were then subjected to thermal treatment at 400 °C in sealed glass ampoules to track the decomposition polychlorinated dibenzo-p-dioxins and furans (PCDD and PCDF). Temperature programmed desorption experiments in the 30–900 °C range also enabled monitoring of thermally decomposing ashes by Fourier Transform Infrared (FTIR) spectroscopy as well as thermally desorbing effluent gases by mass spectrometry. In addition, one ash was doped with ¹³C-labelled PCDD and PCDF to evaluate the potential of the experimental setup for elucidating the thermal desorption of the organic molecules. It was found that in ashes with high carbon content PCDD and PCDF decomposition were led pronounced, and that PCDD degraded more readily than PCDF.
显示更多 [+] 显示较少 [-]