Showing papers in "Chemosphere in 1994"

TL;DR: In this article, the authors present a data base containing information relevant to the setting of Toxic Equivalency Factors (TEFs), and, based on the available information, to assess the relative potencies and to derive consensus TEFs for PCDDs, PCDFs and dioxin-like PCBs.

TL;DR: In this article, the photochemical mineralization of 4-chlorophenol (4-CP) and of a wastewater from dyehouse industry by the methods UV/O3, UV/H2O2 and UV/TiO2 (photo-Fenton reaction) were compared.

TL;DR: Results indicate that the rhizosphere zone surrounding the roots of some plant species may selectively foster the growth of PCB-degrading microbes, and introduction of a carefully selected plant species at PCB-contaminated sites has promise as a new means of enhancing and maintaining microbial degradation of PCBs.

TL;DR: The risk assessment for bioaccumulation presented here is more comprehensive than the EU Technical Guidance Document (TGD) for new and existing substances and takes into account the complexity of bio Accumulation processes including uptake and depuration kinetics, bioconcentration factor, metabolism, and bound residues, relating these data to critical body burden concentrations.

TL;DR: In this article, a more mechanistic explanation for the prediction of photo-induced toxicity of polycyclic aromatic hydrocarbons (PAHs) was proposed, which is the result of competing processes such as stability and light absorbance which interact to produce a complex, multilinear relationship between toxicity and chemical structure.

TL;DR: In this paper, the photooxidation of two non-biodegradable azo dyes, acid red 1 and acid yellow 23, were studied in an UV/hydrogen peroxide photochemical reactor with a 5 kW low pressure mercury lamp.

TL;DR: All the fish samples contain high concentrations of Cu, Ni and Zn, while Co, Mo, Pb and V were not detected, which may be directly related to the contamination of the Tigris River by Ergani Copper Plant and the geochemical structure of this region.

TL;DR: The results of these preliminary experiments suggest that the rhizosphere of certain plant species may be important for facilitating microbial degradation of pesticide wastes in soils and beneficial for remediating pesticide-contaminated sites as discussed by the authors.

TL;DR: It was observed that all of the sulphur compounds investigated significantly accelerated the reaction and the mechanisms of the processes studied as well as their possible influence on the efficiency of the iron-induced dehalogenation of pollutants are discussed.

TL;DR: A review of the physical properties of chlorophenols and alkyl phenols, including acid dissociation constant, aqueous solubility, vapour pressure, octanol-water partition coefficient, Henry's law constant or air water partition coefficients, bioconcentration factor and sorption partition coefficient are presented in this article.

TL;DR: In this paper, the authors investigated PCB and dioxin exposure of Dutch women and their neonates, levels were examined in 418 mother-infant pairs and four nonplanar PCB congener levels (PCB 118, 138, 153 and 180) were measured in maternal plasma and in umbilical cord plasma.

TL;DR: In this article, trichloroethylene was transformed by iron powder (4.1g/L) in oxygen-free, HEPES-buffered (pH 7) water at 50°C with a half-life of 20 days.

TL;DR: In this article, a new method for source identification of polychlorinated dibenzo-p-dioxins (PCDDs) was developed based on the comparison of the profiles of relative concentrations of 2,3,7,8-substituted PCDD/PCDF congeners.

TL;DR: In this paper, the nitro musks -musk xylene, musk ketone and musk tibetene -used as fragrances in cosmetics and detergents were determined in a total of 32 human adipose tissue samples and 23 human milk samples from northern Germany.

TL;DR: The first-order rate constant of sunlight photolysis (k p ) for NP was estimated at 0.09 m 2 /(kWh) as discussed by the authors, which corresponds to a half-life of 10-15 hours under continous clear sky, noon, summer sunlight in the surface layer of natural waters.

TL;DR: In this paper, the uptake of eight organic xenobiotics from soil by plants was studied in a closed aerated laboratory soil-plant system which allowed to distinguish between uptake via the roots and via the leaves after evaporation.

TL;DR: Tissue specific data demonstrated that elimination via the gall bladder is an important excretion route and environmental variables appeared to influence bioconcentration of ionic surfactants.

TL;DR: This compilation of data on toxicological and ecotoxicological endpoints for sulfonic acids reveals a common toxicological profile for the sulfonic acid when all the properties of these substances are taken into consideration.

TL;DR: From investigations with aqueous extracts conclusions on potential risks for groundwater can be drawn, but these tests also seem to allow risk assessments for soil inhabitants, and with these tests comprising dilution series the extent of toxicity for soil organisms can be quantified more precisely than with terrestrial investigations.

TL;DR: A new and efficient protocol for the extraction of polycyclic aromatic hydrocarbons (PAH) from soil samples is described in this article, which is based on two successive steps, including an organic solvent extraction and a methanolic hydrolysis (saponification) of the soil sample.

TL;DR: Anaerobic reductive dechlorination of polychlorinated biphenyls (PCBs) in heat treated, bromoethanesulfonate (BES) treated, and untreated slurries of PCB-contaminated upper Hudson River sediment was investigated to better understand the microorganisms that mediate this process.

TL;DR: In this article, bottom feeding and game fish from each of nearly 400 sites throughout the United States were analyzed for 15 PCDD/PCDFs, PCBs, 21 pesticides and herbicides, and 13 other organic chemicals, and mercury.

TL;DR: Fifty samples of human blood collected in 1992 from the general human population living in five selected areas of the Slovak Republic were analysed for polychlorinated biphenyls and some organochlorine pesticides and PCB levels were found about three times higher levels in the samples from the district where PCB formulations had been produced.

TL;DR: In this article, pooled soil samples from grassland sites were investigated for their contents of heavy metals, PAHs, PCBs (26 sites) and PCDD/Fs (13 sites).

TL;DR: In this paper, an outdoor chamber system with dilute diesel exhaust was used to photochemically generate nitropolycyclic aromatic hydrocarbons (NPAH), and a reaction scheme was proposed for PAH decay and NPAH formation and decay.

TL;DR: In this paper, Fatty acid patterns of phospholipids and lipopolysaccharides were quantitatively determined in six typical environmental samples in order to characterise their microbial community structures.

TL;DR: In this article, a general QSAR model using physicochemical properties of the molecules (i.e. log K ow and pKa) and some relevant properties of soils or sediments was proposed to estimate the sorption behavior of both ionized and non-ionized chemicals.

TL;DR: In this paper, real field data for pesticide release to surface water are compared with data obtained by simulations of a fugacity-derived model, and the comparison between predicted and measured concentrations indicated that the model is a useful tool for the prediction of surface water concentration.

TL;DR: The fate of highly chlorinated (5 to 7 chlorines per molecule) dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners was studied in anaerobic microcosms, using polychlorinated biphenyl (PCB)-contaminated Hudson River sediments, and creosote-contained aquifer sediments as discussed by the authors.

TL;DR: Bacterial and phytotoxicity assays used in this study provided inexpensive and consistent, ecologically relevant information on the toxicity of landfill leachates.