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PubMed2005

Ecotoxicological risk assessment of hospital wastewater: a proposed framework for raw effluents discharging into urban sewer network.

In hospitals a large variety of substances are in use for medical purposes such as diagnostics and research. After application, diagnostic agents, disinfectants and excreted non-metabolized pharmaceuticals by patients, reach the wastewater. This form of elimination may generate risks for aquatic organisms. The aim of this study was to present: (i) the steps of an ecological risk assessment and management framework related to hospital effluents evacuating into wastewater treatment plant (WWTP) without preliminary treatment; and (ii) the results of its application on wastewater from an infectious and tropical diseases department of a hospital of a large city in southeastern France. The characterization of effects has been made under two assumptions, which were related to: (a) the effects of hospital wastewater on biological treatment process of WWTP, particularly on the community of organisms in charge of the biological decomposition of the organic matter; (b) the effects on aquatic organisms. COD and BOD5 have been measured for studying global organic pollution. Assessment of halogenated organic compounds was made using halogenated organic compounds absorbable on activated carbon (AOX) concentrations. Heavy metals (arsenic, cadmium, chrome, copper, mercury, nickel, lead and zinc) were measured. Low most probable number (MPP) for faecal coliforms has been considered as an indirect detection of antibiotics and disinfectants presence. For toxicity assessment, bioluminescence assay using Vibrio fischeri photobacteria, 72-h EC50 algae growth Pseudokirchneriella subcapitata and 24-h EC50 on Daphnia magna were used. The scenario allows to a semi-quantitative risk characterization. It needs to be improved on some aspects, particularly those linked to: long term toxicity assessment on target organisms (bioaccumulation of pollutants, genotoxicity, etc.); ecotoxicological interactions between pharmaceuticals, disinfectants used both in diagnostics and in cleaning of surfaces, and detergents used in cleaning of surfaces; the interactions into the sewage network, between the hospital effluents and the aquatic ecosystem.

Anti-Bacterial Agents↗
PubMed1991

Workshop on human health impacts of halogenated biphenyls and related compounds.

A workshop on the Human Health Impacts of Halogenated Biphenyls and Related Compounds was held to assess the state of current research on these chemicals and to make recommendations for future studies. Participants discussed results from laboratory animal experiments on PCBs, PBBs, dioxins, and dibenzofurans which demonstrate a common mode of toxicological action while also revealing large variations in toxicological potency both within and between these chemical families. These variations demonstrate the importance of congener-specific analyses in future studies of effects of exposure to these compounds. Results from epidemiological studies of environmentally exposed adult and pediatric populations from the U.S., Japan, and Taiwan and occupationally exposed cohorts from around the world were considered. It was concluded that available evidence did not demonstrate serious adverse effects such as cancer, in exposed adult cohorts but did provide indications of possible neurobehavioral effects in children exposed in utero. In addition, workshop participants described newly developed markers of exposure and techniques for assessing endocrinological, immunological, and neurological effects and suggested these be applied to epidemiological studies of the effects of polyhalogenated compounds. Other recommendations included identification of other cohorts and development of a large registry of exposed individuals; performance of detailed studies of reproductive function and outcomes in exposed populations; and follow up of neurobehavioral effects in offspring of exposed women.

Biphenyl Compounds↗
PubMed1989

[Ion exchange interactions on silica gel layers. II. Halogen salts of compounds containing organic tertiary and quaternary nitrogen].

Primary and secondary ion exchanges--of hydrochloric acid and hydrobromic acid salts of well hydrolyzing organic bases as well as quaternary ammonium bromide which are important drug substance--taking place on silica gel using methanol as mobile phase have been investigated by thin-layer chromatographic and spectrophotometric methods. In case of tertiary ammonium salts (hydrolyzing salts) basis linked to silanate ion and halogen acid have been formed by primary ion exchange. During secondary ion exchange halogen acid has exchanged metal ions linked to silanate ions on the layer. In case of non hydrolyzing salts, the quaternary ammonium bromide salts it could not surely be proved by the applied methods whether primary ion exchange had been followed by secondary ion exchange or only primary ion exchange had occurred.

Amines↗
PubMedDate not supplied

[Mechanisms of enhancing UV lihg-induced lipid peroxidation in isolated erythrocyte membranes by organohalogen compounds].

It was found that a number of halogen-containing compounds (chloroform, carbon tetrachloride, difluorodichloromethane, sodium trichloroacetate) enhance the lipid peroxidation induced by UV light (265-300 nm) in isolated erythrocyte membranes. It was shown that the enhancement is realized with participation of excited states of membrane protein tryptophanyls, which may induce the reduction of halogen-containing compounds with formation of radicals having a high oxidative activity. Moreover, halogen-containing compounds decrease the antioxidant protection of membrane lipids owing to an increase in quantum yield of alpha-tocopherol photodestruction.

Erythrocyte Membrane↗
PubMed1997

Exhaled human breath measurement method for assessing exposure to halogenated volatile organic compounds.

The organic constituents of exhaled human breath are representative of blood-borne concentrations through gas exchange in the blood/breath interface in the lungs. The presence of specific compounds can be an indicator of recent exposure or represent a biological response of the subject. For volatile organic compounds (VOCs), sampling and analysis of breath is preferred to direct measurement from blood samples because breath collection is noninvasive, potentially infectious waste is avoided, and the measurement of gas-phase analytes is much simpler in a gas matrix rather than in a complex biological tissue such as blood. To exploit these advantages, we have developed the "single breath canister" (SBC) technique, a simple direct collection method for individual alveolar breath samples, and adapted conventional gas chromatography-mass spectrometry analytical methods for trace-concentration VOC analysis. The focus of this paper is to describe briefly the techniques for making VOC measurements in breath, to present some specific applications for which these methods are relevant, and to demonstrate how to estimate exposure to example VOCs on the basis of breath elimination. We present data from three different exposure scenarios: (a) vinyl chloride and cis-1,2-dichloroethene from showering with contaminated water from a private well, (b) chloroform and bromodichloromethane from high-intensity swimming in chlorinated pool water, and (c) trichloroethene from a controlled exposure chamber experiment. In all cases, for all subjects, the experiment is the same: preexposure breath measurement, exposure to halogenated VOC, and a postexposure time-dependent series of breath measurements. Data are presented only to demonstrate the use of the method and how to interpret the analytical results.

Breath Tests↗
PubMed1984

Reverse-phase high-performance liquid chromatographic determination of halogenated 8-hydroxyquinoline compounds in pharmaceuticals and bulk drugs.

A reverse-phase high-performance liquid chromatographic (HPLC) method was developed for determining iodochlorhydroxyquin, 5,7-dichloro-8-hydroxyquinoline, and 5,7-diiodo-8-hydroxyquinoline in creams, ointments, shampoos, tablets, and bulk drugs. A column packed with 10-micron phenyl-silica and a mobile phase of 0.001 M NiCl2 in acetonitrile-methanol-water (30:20:50) was used to separate the nickel complexes of the three drugs, with detection at 273 nm. Analysis of creams, ointments, shampoos, and tablets gave results close to the label declarations. Recovery of standard material added to samples was greater than or equal to 98%. Linearity of response was shown over a range of 30-150% of label claim for standards of the three drug substances. Multiple analyses of iodochlorhydroxyquin and diiodohydroxyquinoline bulk drugs showed purities of 99.96 and 98.77% with CV of 1.17 and 0.73%, respectively. The HPLC method offers an alternative to current USP procedures, which lack stability-indicating and specificity characteristics.

Chloroquinolinols↗
PubMed1996

Preparation and Characterization of Halogen-Boron-Phosphorus Compounds. X-ray Crystal Structures of X(3)B.P(SiMe(3))(3) and [X(2)BP(SiMe(3))(2)](2) (X = Cl, Br).

The 1:1 mole ratio reactions of boron trihalides (BX(3)) with tris(trimethylsilyl)phosphine [P(SiMe(3))(3)] produced 1:1 Lewis acid/base adducts [X(3)B.P(SiMe(3))(3), X = Cl (1), Br (2), I (5)]. Analogous 1:1 mole ratio reactions of these boron trihalides with lithium bis(trimethylsilyl)phosphide [LiP(SiMe(3))(2)] produced dimeric boron-phosphorus ring compounds {[X(2)BP(SiMe(3))(2)](2), X = Br (3), Cl (4)}. X-ray crystallographic studies were successfully conducted on compounds 1-4. Compound 1 crystallized in the orthorhombic space group Pbca, with a = 13.420(3) Å, b = 17.044(5) Å, c = 21.731(7) Å, V = 4970.6(25) Å(3), and D(calc) = 1.229 g cm(-3) for Z = 8; the B-P bond length was 2.022(9) Å, Compound 2 crystallized in the orthorhombic space group Pbca, with a = 13.581(6) Å, b = 17.106(7) Å, c = 22.021(9) Å, V = 5116(4) Å(3), and D(calc) = 1.540 g cm(-3) for Z = 8; the B-P bond length was 2.00(2) Å. Compound 3 crystallized in the monoclinic space group P2(1)/n, with a = 9.063(5) Å, b = 16.391(8) Å, c = 9.331(4) Å, V = 1379.2(12) Å(3), and D(calc) = 1.676 g cm(-3) for Z = 2; the B-P bond length was 2.023(10) Å. Compound 4 crystallized in the monoclinic space group P2(1)/n, with a = 9.143(5) Å, b = 16.021(8) Å, c = 9.170(4) Å, V = 1342.2(11) Å(3), and D(calc) = 1.282 g cm(-3) for Z = 2; the B-P bond length was 2.025(3) Å. Thermal decomposition studies were performed on compounds 1-4, yielding colored powders with boron:phosphorus ratios greater than 1:1 and significant C and H contamination indicated by elemental analyses.

Journal Article↗
PubMed2000

Halocarbons produced by natural oxidation processes during degradation of organic matter.

Volatile halogenated organic compounds (VHOC) play an important role in atmospheric chemical processes-contributing, for example, to stratospheric ozone depletion. For anthropogenic VHOC whose sources are well known, the global atmospheric input can be estimated from industrial production data. Halogenated compounds of natural origin can also contribute significantly to the levels of VHOC in the atmosphere. The oceans have been implicated as one of the main natural sources, where organisms such as macroalgae and microalgae can release large quantities of VHOC to the atmosphere. Some terrestrial sources have also been identified, such as wood-rotting fungi, biomass burning and volcanic emissions. Here we report the identification of a different terrestrial source of naturally occurring VHOC. We find that, in soils and sediments, halide ions can be alkylated during the oxidation of organic matter by an electron acceptor such as Fe(III): sunlight or microbial mediation are not required for these reactions. When the available halide ion is chloride, the reaction products are CH3Cl, C2H5Cl, C3H7Cl and C4H9Cl. (The corresponding alkyl bromides or alkyl iodides are produced when bromide or iodide are present.) Such abiotic processes could make a significant contribution to the budget of the important atmospheric compounds CH3Cl, CH3Br and CH3I.

Atmosphere↗
PubMed1992

Microbial breakdown of halogenated aromatic pesticides and related compounds.

Considerable progress has been made in the last few years in understanding the mechanisms of microbial degradation of halogenated aromatic compounds. Much is already known about the degradation mechanisms under aerobic conditions, and metabolism under anaerobiosis has lately received increasing attention. The removal of the halogen substituent is a key step in degradation of halogenated aromatics. This may occur as an initial step via reductive, hydrolytic or oxygenolytic mechanisms, or after cleavage of the aromatic ring at a later stage of metabolism. In addition to degradation, several biotransformation reactions, such as methylation and polymerization, may take place and produce more toxic or recalcitrant metabolites. Studies with pure bacterial and fungal cultures have given detailed information on the biodegradation pathways of several halogenated aromatic compounds. Several of the key enzymes have been purified or studied in cell extracts, and there is an increasing understanding of the organization and regulation of the genes involved in haloaromatic degradation. This review will focus on the biodegradation and biotransformation pathways that have been established for halogenated phenols, phenoxyalkanoic acids, benzoic acids, benzenes, anilines and structurally related halogenated aromatic pesticides. There is a growing interest in developing microbiological methods for clean-up of soil and water contaminated with halogenated aromatic compounds.

Bacteria↗
PubMed1977

Photocontact dermatitis to halogenated salicylanilides and related compounds. Our experience between 1967 and 1975.

We evaluated the role of the halogenated salicylanilides and related compounds in the development of photocontact dermatitis between 1967 and 1975 as seen at the University of California, San Francisco clinic. During this period positive photopatch tests to at least one of these chemicals were detected in 98 patients. Prior to 1967, tetrachlorosalicylanilide and the brominated salicylanilides were the most common offenders. Declines occurred in number of patients with positive photopatch tests and patch tests to these agents as well as the number of patients tested to these agents during this period; ie, almost three times as many people were tested and four times as many had positive photopatch tests in the last six months of 1967 as compared to the first nine months of 1975. The most striking reduction in numbers of patients with positive tests occurred after 1968, but the most notable reduction in the total number of positive photopatch tests occurred after 1970. We concluded that these results were most likely due to removal from the market of the more potent photosensitizing chemicals and increased physician familiarity with the disease process.

Adult↗