Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HALOGEN COMPOUNDS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMed2006

Pilot-scale laboratory waste treatment by supercritical water oxidation.

Supercritical water oxidation (SCWO) is a reaction in which organics in an aqueous solution can be oxidized by O2 to CO2 and H2O at a very high reaction rate. In 2003, The University of Tokyo constructed a facility for the SCWO process, the capacity of which is approximately 20 kl/year, for the purpose of treating organic laboratory waste. Through the operation of this facility, we have demonstrated that most of the organics in laboratory waste including halogenated organic compounds can be successfully treated without the formation of dioxines, suggesting that SCWO is useful as an alternative technology to the conventional incineration process.

Conservation of Natural Resources↗
PubMedDate not supplied

[Current status of bath water treatment techniques].

The Federal German DIN standard No. 19644 that has been enforced in West Germany since 1989 had to be revised in view of the fact that German legislation is expected to issue an ordinance on swimming pool and public bath water within the framework of the Federal Communicable Diseases Act; furthermore, the need for revision also arose from the solution of the hygienic problems of treatment and disinfection of warm whirlpool water, and from the necessity of modifying several now outdated regulations. It is the aim of public health legislation to prevent health risks of bathers and of attendant staff by Legionella pneumophila in all types of basins with additional water cycles and intake of air (aerosol formation); likewise, adverse health effects of side reaction products of the disinfectant chlorine (i. e. chloroamines and halogenated organic compounds, especially the trihalomethanes) must be avoided. Recent research has shown that these aims can be achieved by altering the mode of running and backwashing filters of all process combinations including those using ozone and introducing an additional absorption on powdered activated carbon, and the process combination of flocculation-filtration-chlorination. Improved treatment would be without effect if turnover rates could not be assessed reliably for basins of irregular geometry--as they are preferably used today--operated with additional water cycles involving intake of air. Lack of costly investigations prompts users to estimate turnover rates on the basis of experience collected with basins of square or rectangular dimensions.

Baths↗
PubMed1994

Chlorination of drinking water and cancer incidence.

Epidemiological studies report associations between cancer mortality and type of drinking water source. Different studies appeared to lend some support to the hypothesis that surface waters contain higher levels of human carcinogens than groundwater sources. The possible contaminants that might play such a role are the halogenated organic compounds produced by the chemical reaction between organic materials in water and chlorine used for disinfection. Chlorine reacts with naturally occurring organic compounds in the water to form haloforms. Valencia Province of Spain relies almost exclusively on groundwater for its public drinking water, but the city and surrounding urban areas rely on superficial water. The chlorination used in the superficial water includes several phases: prechlorination, coagulation, filtration, and, finally, postchlorination, which shows the possible formation of organohalogenated compounds. To find an association between stomach and bladder cancer mortality with the type of water source, we studied 261 municipalities of Valencia Province. We calculated sex-specific standardized mortality ratios for deaths occurring between the 1985 to 1989 (census statistics), and we carried out a relative-risk calculation associated with the differences between superficial and groundwater supplies.

Chlorine↗
PubMed1997

Identification of CYP1A5 as the CYP1A enzyme mainly responsible for uroporphyrinogen oxidation induced by AH receptor ligands in chicken liver and kidney.

Uroporphyrinogen is an intermediate of the heme biosynthetic pathway. The oxidation of uroporphyrinogen to uroporphyrin (UROX) has been demonstrated to be catalyzed by mammalian CYP1A2. This reaction has an important role in uroporphyria caused by halogenated aromatic compounds. Two CYP enzymes induced by Ah receptor ligands were purified recently from chick embryo liver. One, designated CYP1A5, was preferentially active in arachidonic acid epoxygenation and the other, designated CYP1A4, in 7-ethoxyresorufin deethylase (EROD) and aryl hydrocarbon hydroxylase (AHH), reactions mainly catalyzed by CYP1A1 in rodents. The amino acid sequences of both CYP1A5 and CYP1A4 are more similar to CYP1A1 than to 1A2, and neither can be classified as an ortholog of mammalian CYP1A1 or 1A2. Here we report that reconstituted purified CYP1A5 was eight times more active than CYP1A4 in catalyzing UROX. The stimulation of UROX by 3,4,3',4'-tetrachlorobiphenyl that has been observed in microsomes was also observed with the reconstituted enzymes. Similar dose response relationships were found for induction of UROX and EROD in both chick embryo liver microsomes and in cultured chick hepatocytes, indicating coinduction of CYP1A5 and CYP1A4. UROX was induced by the Ah receptor ligand, 3-methylcholanthrene, in chicken kidney as well as liver. The findings reported here and other evidence that CYP1A4 and CYP1A5 tend to exhibit CYP1A1 and 1A2-like enzyme activites, respectively, indicate that the division of some enzyme activities among CYP1A enzymes applies to different vertebrate classes.

Animals↗
PubMed1981

Inhibition of housefly oxidative detoxication by phthaleins, fluoresceins and related compounds.

1. Phenolphthalein, halogenated fluoresceins, and other triphenylmethane and diphenylmethane derivatives inhibited biphenyl hydroxylation, aldrin epoxidation and several O-dealkylations in insect abdomen homogenates. Phenolphthalein and eosin (50 muM) were 2-3 times more effective than SKF 525-A and piperonyl butoxide (50 muM) as inhibitors of biphenyl hydroxylation in vitro. 2. The phthaleins, Aurin and Aluminon, inhibited both epoxidation and hydroxylation to similar extents, but fluoresceins, Rhodamine B, Malachite Green, and basic diphenylmethane derivatives preferentially inhibited hydroxylation. 3. Tetrabromophenolphthalein ethyl ester and bis-(N-dimethyl-4-aminophenyl-methane inhibited biphenyl hydroxylation in vivo. Bis-(N-dimethyl-4-aminophenyl) methane synergized the toxic effects of 1-naphthyl N-methylcarbamate in live houseflies.

Abdomen↗
PubMed1999

Volatiles obtained from whole and ground grain samples by supercritical carbon dioxide and direct helium purge methods: observations on 2,3-butanediols and halogenated anisoles.

Volatile compounds were obtained from whole and ground grain samples by two methods. In the supercritical fluid extraction (SFE) method, volatiles were extracted from the grain with supercritical carbon dioxide, trapped at -78 degrees C, and then transferred via a purge-and-trap instrument to a gas chromatograph with mass and infrared detectors (GC-MS/IR) for separation and identification. In the direct-helium-purge method (DHP), volatiles were purged directly from the grain into the purge-and-trap instrument for subsequent transfer to the GC-MS/IR system. With SFE, extraction of volatiles was favored by ground grain, low pressures (</=13.8 MPa), and high temperatures (50-90 degrees C). DHP gave more low molecular weight compounds, while SFE was better for aldehydes, enals, 2, 3-butanediols (dl and meso forms), acetic acid, and chloro- and bromomethoxybenzenes apparently associated with musty odors in sorghums. The diols were present in both musty and normal-odor sorghums.

Anisoles↗
PubMed1979

Mutagenicity of halogenated and oxygenated three-carbon compounds.

Four structurally related three-carbon compounds, known for their antifertility activity in the male, and the brominated derivatives of two of these compounds were tested for mutagenic activity by the Salmonella typhimurium test of Ames et al. In the presence of strain TA-100, a base-pair substituion detector strain, 1,2-dibromo-3-chloropropane (DBCP), was the most active compound tested but required enzymatic conversion by 59 microsomal preparation to an active mutagen. Three of these compounds containing an epoxide group-epichlorohydrin, epibromohydrin, and glycidol-were highly active direct mutagens, not requiring 59 for activation, alpha-Chlorohydrin was the least active compound tested; alpha-bromohydrin was 40 times more active than its chlorinated analog. Epibromohydrin was only slightly more active than epichlorohydrin, but both were highly active. With both of the halogenated epoxides, 59 preparation caused a substantial decrease in mutagenic activity at every concentration tested. All six compounds showed dose-related responsiveness for the base-pair substitution detector strains used. However, they were relatively inactive against the frameshift detector strain of S. typhimurium, TA-98. Glycerol, propylene glycol, and n-propanol, which are also three-carbon compounds containing one or more hydroxy groups, were inactive when trested at high concentrations with strain TA-100.

Alcohols↗