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PubMed1989

Studies on concentration of halogen derivatives in herbal products from various regions of Poland.

The studies covered evaluation of levels of halogen derivative pesticides (p,p'-DDT and its metabolites p,p'-DDD and p,p'-DDE, as well as HCH, DMDT, aldrin and dieldrin) in herbal raw materials picked up in various regions of Poland in 1983. Qualitative analyses have been carried out with the TLC method whereas for quantitative analyses the GLC method has been applied. It has been found that the most frequently occurring are p,p'-DDT and its metabolites. The highest concentrations of these compounds have been observed in herbs from Lower Silesia and from the Bydgoszcz regions. Also in the region of Białystok concentrations of these compounds are generally higher than in other parts of Poland. Other pesticides have been found in a lesser number of herbal raw materials and in considerably lower concentrations.

Chromatography, Gas↗
PubMed1979

Carcinogenicity of halogenated olefinic and aliphatic hydrocarbons in mice.

A series of 15 halogenated hydrocarbons of industrial and environmental importance were tested for carcinogenicity by chronic administration by one or more routes in Ha:ICR Swiss mice. Not all compounds were tested by the four routes of administration used. Allyl chloride, 1,2-dibromo-3-chloropropane, and vinylidene chloride were active as skin tumor initiators in the two-stage carcinogenesis assays; phorbol myristate acetate was used as a promoter. 1,2-Dibromoethane was the only compound that induced a significant incidence (p less than 0.05) of skin papillomas, skin carcinomas, and lung tumors by repeated skin application. 1,2-Dichloroethane, 1,1,2,2-tetrabromoethane, and 1,2-dibromo-3-chloropropane induced lung and/or stomach tumors by repeated skin application. Two compounds showed sarcomagenic activity by sc injection; they were cis-1,3-dichloropropene and 2-chloropropanal. By intragastric intubation, 1-chloropropene and 2-chloropropanal induced significant numbers of stomach tumors. Vehicle, no-treatment, and positive control groups were included in these tests. The following compounds were also tested by one or more of the four routes but were inactive by the criteria used; i.e., they showed P = 0.05 or greater than 0.05: trichloroethylene, tetrachloroethylene, hexachlorobutadiene, chloroacetaldehyde, 1-chloropropene oxide (cis and trans), and trichloroethylene oxide.

Animals↗
PubMed1985

Studies on the mechanism of action of halogenated aromatic hydrocarbons.

The halogenated aromatic hydrocarbons (dibenzo-p-dioxins, dibenzofurans, azo[xy]benzenes and biphenyls), a group of toxic chemicals in the environment, (a) are approximate isostereomers; (b) produce a similar pattern of biologic responses and (c) appear to act by a common mechanism. These compounds reversibly bind to a soluble receptor protein to initiate a coordinate gene expression, analogous to the action of steroid hormones. This receptor controls two distinct and dissociable pleiotropic responses: (a) the induction of microsomal monooxygenase activity and other drug metabolizing enzymes and (b) morphologic (i.e. toxic) changes, many of which involve altered cell proliferation and/or differentiation in epithelial tissues.

Animals↗
PubMedDate not supplied

Determination of halogenated phenols in raw and potable water by selected ion gas chromatography-mass spectrometry.

Pentafluorobenzylation and in situ acetylation are compared in the determination of phenol and halogenated phenols in water samples. The latter technique is considered superior to the former for determining phenols at the ng/L level because of less background interference and better recoveries (80% or better except for pentachlorophenol and trichloroguaiacol which had recoveries of about 60%). Further evaluation of the in situ technique by electron capture gas chromatography and gas chromatography-mass spectrometry shows that the latter, in the selected ion monitoring mode, is more suitable because, unlike GC-ECD, it can confirm and quantitate all phenols. In particular, GC-ECD could not detect even high levels of phenol and the monohalogenated phenols. Phenols at 5-473 ng/L were detected in some Canadian drinking water supplies by the in situ acetylation technique combined with GC-MS.

Gas Chromatography-Mass Spectrometry↗
PubMed1970

Evaluation of compounds for insecticidal activity on adult mosquitos. 4. Insecticidal activity and physical properties of some halogenated organophosphorus esters.

The effects of changes in structure upon toxicity to adult mosquitos and upon physical properties which are important in determining contact effectiveness and residual activity are described for a group of O,O-dialkyl O-halogenated-phenyl phosphates, phosphorothionates and phosphamido(thio)ates. This group includes such established insecticides as fenchlorphos, bromophos and iodofenphos.

Animals↗
PubMed1979

Analytical characteristics of late-eluting halogenated flame retardants.

The analytical characteristics of halogenated flame retardants were studied. Suitable electron capture gas-liquid chromatographic conditions were developed, and retention times and sensitivity responses were obtained. The behavior of these industrial chemicals through the AOAC multiresidue method for nonfatty foods was studied using fish as the test substrate. Of the 24 flame retardants investigated, 23 were recovered (85-110%) using the AOAC method.

Animals↗
PubMed1978

Rapid determination of light halogenated hydrocarbons in urine.

We describe a rapid method for determining light halogenated hydrocarbons (LHH) in urine by electron capture gas-liquid chromatography. The hydrocarbons are extracted from urine into pentane. A 2-microliter injection of the pentane extract provides a detection limit of less than 1 microgram/liter.

Adult↗
PubMedDate not supplied

Taste aversions to several halogenated hydrocarbons.

Five halogenated hydrocarbons (chloral; trichloroethylene; 1,2-dichloroethylene; 1,2-dichloroethane and 1,1,2-trichloroethane) were evaluated in the taste aversion paradigm to determine thresholds for producing aversion effects. Comparisons were made between threshold determination for acute and repetitive conditioning trials. All of the compounds produced saccharin aversions following one pairing of the chemical exposure with saccharin ingestion. Repetitive conditioning trials did not alter the thresholds for producing aversions with any of the five compounds evaluated. Potencies of the compounds in producing conditioned taste aversions were chloral greater than 1,1,2-trichloroethane greater than 1,2-dichloroethane greater than 1,2-dichloroethylene greater than trichloroethylene.

Animals↗
PubMed1981

[New aspects for the evaluation of health effects caused by exposure against halogenated hydrocarbons at the working place. A literature review (author's transl)].

Halogenated hydrocarbons with over 150 toxicological relevant substances represent a considerable group among the numerous noxes at the working-places. Tri- and perchloroethylene are industrially widely used solvents for cleaning, degreasing and extraction. At the workplace the main amount of intake occurs via lung. Hepato-, nephro-, neuro- and cardiotoxicological effects are important solvent-induced health impairments. If the valid maximum concentrations in the work area (MAK-value) for the specific substance is not exceeded, altogether health hazards are impropable. With information of the "Unfallverhütungsbericht" only 23 cases of intoxications at the workplace were indemnified in 1977 for the first time. The causes for this low number are: installation of closed equipments, automation of the procedures and improvement of the personal hygiene. However praxis in occupational medicine shows, that there is a great number of persons in small firms that has contact with these solvents. For the surveillance and judgement of these solvent-exposed persons exist two methods. First the airborne concentration of the chemical compound can be determined at the working area. Second the solvent and/or its metabolites can be quantitative analyzed in the biological material. This method, called "biological Monitoring (BM)" has important advantages. BM should be prefered in cases of non-continuous, short-term exposures to concentrations of high degree. The judgement has to be done in relation to biological permissible limits (Biologische Arbeitsstoff-Toleranz-Werte, BAT, biological threshold limit values, BTLV's). Based on our longtime experience this specific and sensitive method should be used with priority.

Cardiovascular Diseases↗
PubMed1981

[Modification of hepatotoxic effect of halogenated hydrocarbons on partially hepatectomized rats (author's transl)].

The effect of hepatectomy on the hepatotoxic effect of halogenated hydrocarbons was studied. Male rats received oral administration of chloroform of carbon tetrachloride at a single dose of 500 mg/kg, 3 days prior to or after the partial hepatectomy. The hepatotoxic effect of the toxins was modified in a different manner according to the time of the hepatectomy. In the animals hepatectomized 3 days after the hepatotoxins administration, histological changes of the liver were similar to those of the non-hepatectomized rats, except with an increase in the activity of GOT and GPT. Contrary, in the animals hepatectomized 3 days prior to the hepatotoxins administration, the toxic effect of the chemicals was less enhanced than in the non-hepatectomized animals.

Alanine Transaminase↗
PubMed1980

Effects of halogenated benzenes on arylesterase activity in vivo and in vitro.

Hepatic arylesterase activity was induced by 1,2,4-trichlorobenzene, hexachlorobenzene, 1,2,4-tribromobenzene, and 1,3,5-tribromobenzene but not by 1,3,5-trichlorobenzene or hexabromobenzene. Serum arylesterase was not induced by any of the halogenated benzenes and was inhibited in vivo by 1,2,4-trichlorobenzene, hexachlorobenzene, and 1,3,5-tribromobenzene. It was also inhibited in vitro.

Animals↗
PubMed1994

Potentiation of gamma-aminobutyric acid type A receptor-mediated chloride currents by novel halogenated compounds correlates with their abilities to induce general anesthesia.

The Meyer-Overton hypothesis, predicting that the potency of an anesthetic correlates with its affinity for lipid, is a cornerstone of modern anesthetic theory. Several halogenated compounds were recently found to deviate from this prediction, whereas others did not. We tested the abilities of enflurane and five of these compounds to potentiate gamma-aminobutyric acid (GABA)A receptor responses in Xenopus oocytes expressing alpha 1 beta 2 or alpha 1 beta 2 gamma 2S GABAA receptors. Enflurane and the anesthetic 1-chloro-1,2,2-trifluorocyclobutane (F3) strongly potentiated chloride currents produced by 5 microM GABA with both alpha 1 beta 2 and alpha 1 beta 2 gamma 2S receptors. This potentiation decreased as the GABA concentration was raised. The transitional compound (less potent than predicted by its lipid solubility) 2-bromoheptafluoropropane produced modest enhancement, whereas three nonanesthetics (neither causing anesthesia in vivo nor decreasing the requirement for known anesthetics), 1,2-dichlorohexafluorocyclobutane, 2-chloroheptafluoropropane, and 2,3-chlorooctafluorobutane, did not affect GABAA receptor currents. Although all five compounds were predicted to be anesthetics by the Meyer Overton hypothesis, only F3 behaved as an anesthetic in vivo and only F3 markedly potentiated GABAA receptor responses in oocytes. These results strongly implicate the GABAA receptor in general anesthesia. Fluorescence polarization studies showed that anesthetics (enflurane and F3), but not nonasthetics (1,2 dichlorohexafluorocyclobutane and 2,3-chlorooctafluorobutane) disordered membrane lipids. Thus, for the compounds studied actions on both GABAA receptor function and lipid order distinguish between anesthetics and nonanesthetics.

Anesthetics, General↗
PubMedDate not supplied

[Study of the effect of halogen series anions on DNA molecular conformation in solution].

Effect of halogen-series anions (F-, Cl-, Br-, I-) in sodium, potassium and ammonium halogide solutions with ionic strengths of mu = 0.1, 0.01, and 0.005 M on the dimensions and thermodynamic rigidity of the DNA molecule in solution was studied by viscosimetry and flow birefrigence. Flow birefrigence measurements showed that close-range interactions along the macromolecular chain and accordingly the persistent length of DNA did not change with a change of anion. However, the specific volume of the molecule depends on the anion type. In our opinion, the observed effect is connected with the different ability of anions to "neutralize" the cation screening effect on DNA phosphates.

Animals↗
PubMed1993

The groundwater pollution in Lombardy (north Italy) caused by organo-halogenated compounds.

This paper deals with the phenomenon of the presence of organo-halogenated compounds in groundwaters of the Lombardy Region (North Italy). The regionwide study evidentiated the magnitude of the phenomenon, since these compounds are employed in all productive and household activities. The main cause of groundwater contamination is the infiltration of industrial wastewater: in the Province of Mantova, for example, organic chlorinated solvents have their origin in the NaOCl wastewater treatment for ammonia removal. Organic alogenated compounds in waters intended for human consumption in Lombardy are present in 510 wells over 92 townships, affecting a population of 1,934,133 equivalent to 20% of the total resident population (1991 data). Maximum observed concentrations are related to trielin and tetrachloroethilene. Water treatment was achieved through aeration (stripping) and activated carbon or resin adsorption; in a few instances, also hydraulic interventions were implemented.

Hydrocarbons, Halogenated↗
PubMedDate not supplied

[Halogenated hydrocarbons in human milk].

The concentration of several chloro-organic derivatives as PBC, HCH isomers, HCB, and DDT and its metabolites was assayed in the human milk. Sixty two samples collected from 15 human milk donors from Warsaw and surroundings were studied. The results show, that PCB is present in the most elevated concentration in comparison with the remaining compounds (mean 0.0241 mg/dl of milk or 0.723 mg/kg of fat). Substantial differences in halogenated hydrocarbons excretion with human milk were noted during lactation. However no correlation between the amounts of excreted fat and these compounds levels in the milk was seen. No tendency to the decrease of the excretion of assayed compounds with milk during lactation was observed.

Environmental Exposure↗
PubMedDate not supplied

On-line steam distillation/purge and trap analysis of halogenated, nonpolar, volatile contaminants in foods.

An on-line, steam distillation/purge and trap gas chromatographic procedure is described for determination of halogenated analytes in foods and beverages. Recoveries were generally >80% (versus aqueous standards) from vegetable oil, flour, root beer, cream (10% butter fat), and milk spiked at 1-3 micrograms/kg for each of the 32 analytes studied. Analytes ranged in volatility from vinyl chloride to 1,2,3,4-tetrachlorobenzene. Repeatabilities from aqueous standards were <10% for most analytes. For a 1 g food sample, method detection limits ranged from 0.02 to 0.2 micrograms/kg for the 32 analytes. Reduced recoveries for less volatile analytes, however, occurred when steam-distillable, nonpolar food components were carried to the sparger. This effect was observed for citrus beverages containing steam-volatile limonene, roasted and ground coffees, and some salad dressings. The method was applied to a variety of foods.

Chromatography, Gas↗
PubMed1997

[Theoretical rationale for structure-genotoxicity relationships in the series of halogenated short-chain aliphatic compounds for mammals and bacteria].

Structure-genotoxicity relationships for mammals and structure-mutagenic activity relationships for bacterial were derived in the series of halogenated short-chain hydrocarbons and alcohols, by using the calculated quantum chemical parameters, namely the energy differences of frontier molecular orbitals and the electronic characteristics of the probable metabolites.

Alcohols↗