Abstract  A simple HPLC method with on-line preconcentration has been developed for the separation and the determination of trace levels of benzylchloride, chlorobenzene, naphthalene, and biphenyl in tap and surface water. The separation was achieved on the column 150 × 3.2 mm filled with Separon SGX C18, dp=5mUm with the spectrophotometric detection at 220 and 250 nm. To enhance the selectivity of separation a water - methanol gradient was used. The method permits the measurement of benzylchloride, chlorobenzene, naphthalene, and biphenyl in environmental samples, with the detection limits of 10 ppt of naphthalene, 55 ppt of biphenyl, 90 ppt of benzylchloride, and 185 ppt of chlorobenzene (sample volume was 100 ml of water samples). The assayed procedure has been applied for the quantitative determination of benzylchloride, chlorobenzene, naphthalene and biphenyl in tap water and river water.

Abstract  The introduction of foreign organic hydrocarbons into the environment in recent years, as in the widespread use of antibiotics, has resulted in the evolution of novel adaptive mechanisms by bacteria for the biodegradation of the organic pollutants. Plasmids have been implicated in the catabolism of many of these complex xenobiotics. The catabolic genes are prone to undergo genetic rearrangement and this is due to their presence on transposons or their association with transposable elements. Most of the catabolic transposons have structural features of the class I (composite) elements. These include transposons for chlorobenzoate (Tn5271), chlorobenzene (Tn5280), the newly discovered benzene catabolic transposon (Tn5542), and transposons encoding halogenated alkanoates and nylon-oligomer-degradative genes. Transposons for the catabolism of toluene (Tn4651, Tn4653, Tn4656) and naphthalene (Tn4655) belong to class II (Tn3 family) elements. Many catabolic genes have been associated with insertion sequences, which suggests that these gene clusters could be rapidly disseminated among the bacterial populations. This greatly expands the substrate range of the microorganisms in the environment and aids the evolution of new and novel degradative pathways. This enhanced metabolic versatility can be exploited for and is believed to play a major part in the bioremediation of polluted environments.

Abstract  Toxic emissions from municipal solid waste (MSW) and hazardous waste incineration are discussed, with reference to recent reviews and to government standards and controls. Studies of known effects of aromatic hydrocarbons, other organics, dioxins, metals, and gases, on fish, soils, plants, and particularly humans are briefly reviewed. A summary of potential problems with existing and proposed incineration is developed, including: (1) lack of toxicity data on unidentified organic emissions; (2) unavoidability of hazardous metal emissions as particles and volatiles; (3) inefficient stack operation resulting in unknown amounts of increased emissions; (4) formation in the stack of highly toxic dioxins and furans, especially under inefficient conditions, and their build-up in the environment and in human tissue; (5) the lack of adequate disposal techniques for incinerator fly ash and wash-water; (6) the contribution of emitted gases such as NO2, SO2and HCL to smog, acid rain, and the formation of ozone, and the deleterious effects of these on human respiratory systems; (7) the effects and build-up in human tissue of other emitted organics such as benzene, toluene, polychlorinated biphenyls (PCBs), alkanes, alcohols, and phenols; (8) lack of pollution-control and real-time efficiency-monitoring equipment in existing installations. The inability of regulatory bodies historically to ensure compliance with emission standards is discussed, and a concluding opinion is offered that it is inadvisable to engage in new incinerator construction with present knowledge and conditions.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Beginning in 1998, electric power plants burning coal or oil must estimate and report their annual releases of toxic chemicals listed in the Toxics Release Inventory (TRI) published by the U.S. Environmental Protection Agency (EPA). This paper identifies the toxic chemicals of greatest significance for the electric utility sector and develops quantitative estimates of the toxic releases reportable to the TRI for a representative coal-fired power plant. Key factors affecting the magnitude and typ

Abstract  Concurrent rain and air sampling was conducted for seven rain events in Portland, Oregon during February through to April of 1984. Concentration data are presented for a number of neutral organic compounds for both the rain-dissolved phase and the atmospheric gas phase. The ambient temperature averaged 8°C. Measured gas scavenging ratios ranged from 3 for tetrachloroethene to 105 for dibutylphthalate, and were generally 3–6 times higher than those calculated from Henry's Law constant (H) values at 25°C taken from the literature. This discrepancy was due to the inappropriateness of applying 25°C H data at 5–10°C. Indeed, excellent agreement between the measured and predicted gas scavenging ratios was found for several polycyclic aromatic hydrocarbons for which temperature-dependent H data were available. These results demonstrate that equilibrium between rain and the atmospheric gas phase is attained for non-reactive neutral organic compounds.

Abstract  The current work focuses on the detailed evolution of the chemical composition of both the gas- and aerosol-phase constituents produced from the OH-initiated photooxidation of naphthalene under low- and high-NO(x) conditions. Under high-NO(x) conditions ring-opening products are the primary gas-phase products, suggesting that the mechanism involves dissociation of alkoxy radicals (RO) formed through an RO(2) + NO pathway, or a bicyclic peroxy mechanism. In contrast to the high-NO(x) chemistry, ring-retaining compounds appear to dominate the low-NO(x) gas-phase products owing to the RO(2) + HO(2) pathway. We are able to chemically characterize 53-68% of the secondary organic aerosol (SOA) mass. Atomic oxygen-to-carbon (O/C), hydrogen-to-carbon (H/C), and nitrogen-to-carbon (N/C) ratios measured in bulk samples by high-resolution electrospray ionization time-of-flight mass spectrometry (HR-ESI-TOFMS) are the same as the ratios observed with online high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS), suggesting that the chemical compositions and oxidation levels found in the chemically-characterized fraction of the particle phase are representative of the bulk aerosol. Oligomers, organosulfates (R-OSO(3)), and other high-molecular-weight (MW) products are not observed in either the low- or high-NO(x) SOA; however, in the presence of neutral ammonium sulfate seed aerosol, an organic sulfonic acid (R-SO(3)), characterized as hydroxybenzene sulfonic acid, is observed in naphthalene SOA produced under both high- and low-NO(x) conditions. Acidic compounds and organic peroxides are found to account for a large fraction of the chemically characterized high- and low-NO(x) SOA. We propose that the major gas- and aerosol-phase products observed are generated through the formation and further reaction of 2-formylcinnamaldehyde or a bicyclic peroxy intermediate. The chemical similarity between the laboratory SOA and ambient aerosol collected from Birmingham, Alabama (AL) and Pasadena, California (CA) confirm the importance of PAH oxidation in the formation of aerosol within the urban atmosphere.

Abstract  We have developed a rapid and simple gas toxicity evaluation system based on bioluminescence inhibition of a marine-derived wild luminous bacterium, Vibrio fischeri. The luminous bacteria were trapped using a thin polyion complex membrane in order to allow semi direct contact between the bacteria and toxic gases. Bioluminescence inhibition ratios of the present system to six reference gases, including benzene, trichloroethylene, acetone, NO(2), SO(2), and CO, were evaluated, and dose-response relationships were successfully obtained after 15 min of gas exposure, except for CO gas. The sensitivity to the five gases except for CO gas of the present system was 1-3 orders of magnitude higher than that in acute animal tests. The present system also allowed for the evaluation of overall toxicity of some environmental gases containing various chemicals. These results clearly demonstrated that the present system would be a valuable prototype for rapid and on-site acute toxicity detection of a gas mixture, such as environmental gases.

Abstract  General Motors; State of Nevada. Twenty-three vehicles that were recruited by remote sensing and roadside inspection and maintenance (I/M) checks during the 1994 Clark and Washoe Remote Sensing Study (CAWRSS) were tested on the IM240 cycle usinga transportable dynamometer. Six of these vehicles emitted visible smoke. Total gas-phase hydrocarbon (HC), carbonmonoxide (CO), and nitrogen oxides (NOx) exhaust concentrations were continuously measured in the diluted exhaust stream from the constant volume sampler (CVS)during IM240 testing. Two isokinetic PM-l0 samples were collected simultaneously using cyclones and filter holder sconnected to a dilution tube. Teflon filters were collected for total mass and then extracted for chloride, nitrate, and sulfate ions. Quartz filters were analyzed by the thermal/optical reflectance method for organic and elemental carbon. The quartz filters and backup vapor traps were then extracted and analyzed by GC/MS for 28 separate polynuclear aromatic hydrocarbons. Mass emission rates of PM-l0 per vehicle ranged from 5.6 to over 1300 mg/mi, with most of the mass attributable to carbon. Except for one vehicle with high sulfate emissions, the ion emissions were relatively low. Total PAH emissions were in the range of 10-200 mg/mi.

Abstract  In this review an attempt is made to integrate our knowledge about sensory receptors lining the respiratory tract and the reflex reactions evoked following their stimulation by inhaled chemicals. The nature of the chemicals capable of eliciting sensory irritation and the mechanisms proposed for their interactions with nerve endings are reviewed. Methods proposed for evaluation of the effects of airborne chemicals in animals are reviewed and their usefulness for predicting the reactions to be expected in humans is evaluated. The application of these methods in industrial hygiene also discussecl. Articles reviewed Include mainly those concerned with acute exposures and the effects of the chemicals following stimulation of nervous structures in the respiratory tract. Other actions of inhaled chemicals such as their effect on ciliary motion, mucous secreting cells, etc. are excluded. Airborne chemicals can also impinge on the cornea and skin. Their action on nerve endings in these structures is compared with their action on nerve endings in the upper respiratory tract in an attempt to integrate the results obtained for chemicals capable of stimulating the "common chemical sense" receptor.

Abstract  1. Several aromatic and olefinic compounds are converted to intermediate arene and alkene oxides by mammalian mono-oxygenases. Intermediate arene oxides rearrange non-enzymically to phenols. Arene and alkene oxides are converted by epoxide hydrases to vicinal diols and by glutathione S-epoxide conjugases to glutathione conjugates. Due to their high electrophilic reactivity, such oxiranes also bind to proteins, RNA and DNA. Mutagenic, carcinogenic and cytotoxic effects of several aromatic and olefinic compounds appear to be due to the formation of intermediate epoxides and their reaction with tissue constituents. Whether a given aromatic or olefinic compound produces such an effect would thus depend on a variety of factors, such as the relative rate of formation and degradation of the intermediate oxirane, on its stability with respect to spontaneous isomerization to the corresponding phenol and on its chemical electrophilic reactivity. 2. Epoxide hydrases, which convert such intermediate oxiranes to much less reactive vicinal diols, have been studied in greater detail. Epoxide hydrase activity is found in mouse, rat, guinea-pig, rabbit, pig, Rhesus monkey and human liver. Activity is high in liver, low in kidney, very low in intestine and lung and not detectable in muscle, spleen, heart and brain. The enzyme is located exclusively in microsomal membranes. Epoxide hydrase activity is markedly increased after pretreatment of rats with phenobarbital or 3-methyl-cholanthrene and during maturation of rats. These increases are reminiscent of similar increases in microsomal mono-oxygenases. However, the extents of induction of total levels of these two enzymes or enzyme families are not comparable and are under separate genetic control. 3. Several stereochemical properties of the reaction catalysed by epoxide hydrases have been studied with microsomal preparations. With styrene oxide and naphthalene oxide as substrates, attack by H218O occurs virtually exclusively at the 2-position. Product glycols which are stereochemically fixed by a ring structure invariably have the trans-configuration. Hydration of some acyclic alkene oxides has also been found to proceed via a trans-opening of the oxirane-ring. Cyclohexene oxide, benzene oxide and naphthalene 1,2-oxide are converted predominantly to 1R,2R-trans-diols, while in the case of phenanthrene 9,10-oxide the 1S,2S,-trans-diol predominates. 4. Epoxide hydrase from guinea-pig liver microsomes was solubilized and purified, based on an assay with styrene oxide as substrate. The specific activity after the last purification step is about 40 times higher than in the crude homogenate. This increase is not due to the removal of an inhibitor. About 30 % of the activity of the purified preparation is lost within 1-2 days. However, the remaining activity is remarkably stable. Gel electrophoresis of the final (stable) preparation shows one major band corresponding to a mol. wt. of approx. 50 000. However, several minor bands are also present. 5. Several properties of epoxide hydrase were investigated with this purified preparation. While no clearcut pH optimum could be observed with microsomal preparations (broad 'optimum' between 7 and 9) a sharp pH profile was obtained with the purified preparation with its optimum at pH 9. Non-enzymic hydration was significant (>5% only below pH 6·5. The KM with respect to styrene oxide as substrate is 2-8 × 10-4M and the apparent Vmax. 2-4 μmol product/mg N per 5 min. No metal ions or other low mol. wt. co-factors are necessary for maximal activity. High concentrations of substrate inhibit the enzyme, whereas product diols have no effect. Several inhibitors of drug-metabolizing enzymes (SKF 525-A), piperonyl butoxide, αnaphthoflavone) do not influence epoxide hydrase activity, while sulphydryl reagents slightly, but significantly, inhibit the enzyme. Several alcohols, ketones and imidazoles stimulate the enzyme. Kinetic analysis of the activation by the potent stimulator, metyrapone, indicates negative co-operativity with the substrate. 6. The active site of the enzyme readily accommodates, as substrates or competitive inhibitors, monosubstituted oxiranes with a lipophilic substituent larger than an ethyl group, suggesting hydrophobic binding sites near the active site. With oxiranes having such a lipophilic substituent, the enzyme interacts with mono-, 1,1-di- and cis-1,2-disubstituted oxiranes, but not with trans-1,2-disubstituted oxiranes or tri- or tetra-substituted oxiranes, suggesting that increasing bulk around the oxirane ring prevents the approach of the oxirane to the active site. Several oxiranes fused to alicyclic rings (cyclohexene oxide, 1,2,3,4-tetrahydronaphthalene 1,2-epoxide) are potent inhibitors but very poor substrates. Kinetic analysis revealed non-competitive inhibition with respect to the substrate, styrene oxide. Styrene sulphide (an analogue of the competitive inhibitor, styrene oxide) but not cyclohexene sulphide (an analogue of the non-competitive inhibitor, cyclohexene oxide) has inhibitory activity, suggesting differing structural requirements for the sites involved in competitive and non-competitive inhibition. The most potent inhibitor discovered so far is 1,1,1-trichloropropene 2,3-oxide, which is on the other hand a poor substrate. Inhibition by this compound is of the un-competitive type. Structure-activity relationship for substrates and inhibitors of purified human epoxide hydrase are qualitatively identical to the ones discussed above for the purified guinea-pig enzyme. 7. Evidence suggesting the presence of more than one liver enzyme capable of hydrating epoxides include differential stabilities, different ratios of hydrase activity towards various epoxides in preparations from different species, a different purification factor (activity of the purified preparation compared to liver homogenates) towards benzene oxide as compared to several other epoxides, inability to inhibit hydration of styrene oxide (in purified or particulate preparations) with much higher concentrations of benzene oxide. 8. Evidence indicating the presence of a coupled mono-oxygenase-epoxide hydrase multienzyme complex include the following observations. Substantial amounts of dihydrodiols in the urine of animals treated with aromatic hydrocarbons, despite the high instability of intermediate arene oxides, lack of equilibration between pools of naphthalene oxide formed in situ and of exogenous naphthalene oxide, differential inhibition of 'free epoxide hydrases' at concentrations of 1,1,1-trichloropropene 2,3-oxide which do not affect the 'coupled mono-oxygenase-epoxide hydrase system' selective induction of the coupled system by 3-methylcholanthrene, and high epoxide hydrase activities in solubilized and purified cytochrome P-450 and P-448 fractions, where other microsomal enzymes (glucose-6-phosphatase, cytochrome c reductase) were absent. Such a coupled mono-oxygenase-epoxide hydrase system may be of great relevance to problems such as carcinogenic properties of arene oxides derived from several polycyclic hydrocarbons, and hepatotoxicity of intermediate arene oxides derived from halobenzenes, by circumventing these adverse effects by their rapid conversion to dihydrodiols. Indeed, pretreatment of rats with 3-methylcholanthrene, which selectively induces this coupled system, provides protection from chlorobenzene-evoked hepatotoxicity, whereas pre-treatment with phenobarbital increases the toxic effect, although it induces the total level of epoxide hydrase to a much greater extent than 3-methylcholanthrene. © 1973 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.

Abstract  #Mouse mammary glands in whole organ culture, previously demonstrated by others to undergo lobuloalveolar development, functional differentiation, and glandular involution, are transformable by carcinogenic aryl amines and amides and their derivatives. The transformation, which involves an escape from the hormonal controls of these processes, results in the formation of nodule-like alveolar lesions that are morphologically similar to presumptive preneoplastic lesions, termed hyperplastic alveolar nodules, which others have found to arise in mice during viral and chemical mammary tumorigenesis. The transformation system discriminates between carcinogens and noncarcinogens of analogous structures in the fluorenyl and naphthylenic chemical series, and is sensitively responsive to the presence of the amino or amide group or their derivatives. In a series of fluorenyl carcinogens, N-2-fluorenylacetamide displayed very high transforming activity > N-hydroxy-N-2-fluorenylacetamide (high activity), and > 2-fluoreneamine and 2-nitrofluorene (low activity). In contrast, the noncarcinogen, fluorene, had little if any transforming activity. The two naphthylenic carcinogens, 1-naphthylamine and 2-naphthylamine, both displayed moderate transforming activity, while the noncarcinogen, naphthalene, had no activity. Control glands treated only with the vehicle (dimethyl sulfoxide) were not transformed. Considerable structural changes at the cellular level were caused by the carcinogens, much less so by the noncarcinogens, and essentially none by the vehicle. It remains to be determined whether the glands transformed by these carcinogens can progress to tumors in vivo. The transformation by the carcinogenic aryl amines and amides and their derivatives (this report) and likewise the malignant transformation by the carcinogenic polycyclic aromatic hydrocarbons (Banerjee and coworkers, Proc. Am. Assoc. Cancer Res., 20: 153, 1979) suggest that mouse mammary gland in whole organ culture may be transformable by a broad spectrum of chemical carcinogens. The prospective linking of this transformation system to the considerable body of information presently known concerning these carcinogens may significantly increase the current understanding of the actions of chemical carcinogens on mammary gland and on epithelial tissues in general.

Abstract  The enzymatic conversion of naphthalene to 1,2-dihydro-1,2-dihydroxynaphthalene has been shown by labeling experiments to proceed with the incorporation of one atom of oxygen from molecular oxygen, the second oxygen atom being derived from water. The initial attack upon the substrate takes place at the α position and the product has been shown by nmr spectroscopy to be the trans diequatorial diol. The over-all mechanism of the oxygenation is discussed in the light of these findings. © 1967, American Chemical Society. All rights reserved.

Abstract  1. Reactions of 1,2-naphthaquinone with amino acids, glutathione and proteins of the lens have been studied in connexion with investigations of naphthalene-induced cataract. 2. Cysteine reacts probably through its amino group with 1,2-naphthaquinone to form either purple or brown compounds with characteristic absorption spectra. 3. Glutathione reacts with 1,2-naphthaquinone through its thiol group. 4. Spectroscopic evidence suggests that 1,2-naphthaquinone reacts with the amino group of amino acids. This reaction may take place in the aqueous humour. 5. The proteins of lens react with 1,2-naphthaquinone to form brown compounds. 6. There is loss of protein thiol in this reaction and the products are less easily digestible by pancreatin than normal lens proteins. 7. The compound of alpha-crystallin and 1,2-naphthaquinone is soluble at neutrality, but the compounds of beta-crystallins and of gamma-crystallins are largely insoluble. 8. The brown reaction products of glutathione or cysteine with 1,2-naphthaquinone catalyse the oxidation of ascorbic acid in the same way as 1,2-naphthaquinone itself. 9. These results are discussed in relation to naphthalene-induced cataract.

Abstract  I have discussed five aspects of lens metabolism and their possible relationship to cataract in man, and this has left me with five fundamental questions to be answered. 1. Are the fluorescent tryptophan derivatives, found only in the lens of man and higher primates, involved in the development of brown nuclear cataract? 2. Is naphthalene cataract in rabbits a model for any type of cataract in man--i.e., are quinones ever formed in the human eye? 3. Is diabetes the only cataract in which osmotic swelling is important? 4. Does self-digestion of protein in the human lens contribute to cataract development? 5. Are the consequences of the abnormal maturation of lens fibers, which occurs in tryptophan deficiency cataract in rats, ever seen in man?

Abstract  The metabolism of naphthalene (91203) was studied in rabbits. Naphthalene was dissolved in warm liquid paraffin and administered by a stomach tube to male rabbits. Doses of 1 or 2 grams (g) were given to each rabbit and repeated at intervals of 2 or 3 days. The alkaline urine excreted during the 24 hours following a 2g dose was collected and analyzed. Following feeding, naphthalene was not present in the alkaline urine but was rapidly formed on acidification from some soluble precursor present in the urine. This unidentified compound was not present in the urine of normal rabbits, and it did not appear after feeding liquid paraffin alone. From the 24 hour urine of a single rabbit fed 1g of naphthalene, 52 milligrams (mg) of the pure compound were obtained. The combined 24 hour urine of three rabbits administered 1g naphthalene each yielded 260mg of the compound. Yields of between 300 and 400mg of the pure compound were obtained from the 48 hour urine of three rabbits each administered a 2g dose. The authors conclude that naphthalene is metabolized in rabbits partly by conjugation with cysteine (52904) and is excreted as mercapturic-acid (616911). It is partly metabolized by conversion into a soluble compound, not yet identified, which yields naphthalene on acidification.

Abstract  As is the case for cytochrome P-450c, arene 1,2-oxides have been identified as initial metabolites when naphthalene and anthracene are oxidized by cytochrome P-450b in a highly purified, reconstituted system. Overall rates of metabolism by cytochrome P-450b are greater than 3-fold and greater than 50-fold lower than the respective rates of metabolism by cytochrome P-450c. For both hydrocarbons, the (-)-(1S,2R)- oxide predominates (74%) with cytochrome P-450b as the terminal oxidant, based on trapping the labile arene oxides as N-acetyl-L- cysteine S-conjugates of known absolute configuration. This result is in marked contrast to data obtained with cytochrome P-450c where the (+)-(1R,2S)-oxides predominate (73-greater than 95%). In the absence of added epoxide hydrolase, the metabolically formed arene oxides rapidly isomerize to phenols. Addition of increasing amounts of epoxide hydrolase to the incubation medium results in the formation of trans- 1,2-dihydrodiols at the expense of phenols from the common arene oxide intermediates. Evaluation of the kinetic parameters (Km and kcat) for the hydration of the (+)- and (-)-enantiomers of both arene oxides by epoxide hydrolase has indicated that the (+)-(1R,2S)-enantiomers exhibit lower values of Km (approximately 1 microM) whereas the values of kcat are similar for both enantiomers of a given arene oxide. These parameters have allowed construction of a mathematical model which predicts the enantiomer composition of the dihydrodiols formed from naphthalene in reconstituted systems containing specific epoxide hydrolase concentrations. The data reported argue against a selective functional coupling mechanism between cytochrome P-450c and epoxide hydrolase in the metabolism of naphthalene and anthracene to the 1,2- dihydrodiols.

Abstract  Absolute configurations of the arene 1,2-oxides formed from napththalene and anthracene by cytochrome P-450c, the predominant isozyme of cytochrome P-450 found in the livers of rats treated with 3- methylcholanthrene, were determined via two different approaches. The first consisted of trapping the arene oxides with N-acetyl-L-cysteine to form S-conjugates, methylation of the conjugates with diazomethane, and separation of the resulting diastereomeric esters by reversed phase high performance liquid chromatography. Analysis by this procedure of the arene oxides formed from radioactive naphthalene and anthracene by a highly purified and reconstituted monooxygenase system containing cytochrome P-450c indicated that 73 and greater than or equal to 95%, respectively, of the metabolically formed arene oxides consisted of the (+)-(1R,2S)-enantiomer. In the second approach, each hydrocarbon was incubated with a reconstituted system containing both cytochrome P-450c and epoxide hydrolase. Under these conditions, the predominant metabolites are trans-1,2-dihydrodiols formed by epoxide hydrolase catalyzed trans-addition of water to the arene oxide intermediates. In both cases, the (-)-(1R,2R)-dihydrodiols predominated; 92% for naphthalene and 99% for anthracene. Enzyme-catalyzed addition of water to (+)- and (-)-anthracene 1,2-oxide and (+)-napthalene 1,2-oxide occurred exclusively (greater than 99%) at the allylic 2-position. The (-)-(1S,2R)-naphthalene 1,2-oxide, however, is converted to a 40:60 mixture of the (-)-(1R,2R)- and (+)-(1S,2S)-dihydrodiols by benzylic and allylic attack, respectively, resulting in increased enantiomeric purity of the dihydrodiol relative to the oxide. Thus, qualitatively and quantitatively both approaches indicate that the (+)-arene (1R,2S)- oxides predominate. The results are discussed in terms of the steric constraints of a proposed model for the catalytic binding site of cytochrome P-450c.

Abstract  HEEP COPYRIGHT: BIOL ABS. The 2- and 3-ring polycyclic aromatic hydrocarbons (PAH), emitted into the atmosphere from combustion sources, exist predominantly in the gas phase. A relative rate technique employing gas chromatography and long path-length differential optical absorption spectroscopy was used to determine rate constants for the gas-phase reaction of OH radicals with naphthalene, phenanthrene and anthracene. By use of a rate constant for the reaction of OH radicals with propene of 4.24 10-12 e544 cm3 molecule-1 s-1, the rate constants obtained were the followig (in units of 10-11 cm3 molecule-1 s-1): naphthalene, 2.35 | 0.06 at 298 | 1? K; phenanthrene, 3.4 | 1.2 at 298 | 1? K and 2.8 THETA 0.6 at 319 | 1? K; anthracene, 11.0 | 0.9 at 325 | 1? K. When an OH radical concentration of 1 was assumed, these rate constants led to atmospheric lifetimes of these PAH due to reaction with OH radicals ofely.

Abstract  Eighty-six species of fungi belonging to sixty-four genera were examined for their ability to metabolize naphthalene. Analysis by thin-layer and high pressure liquid chromatography revealed that naphthalene metabolism occurred in forty-seven species belonging to thirty-four genera from the major fungal taxa. All organisms tested from the order Mucorales oxidized naphthalene with species of Cunninghamella, Syncephalastrum and Mucor showing the greatest activity. Significant metabolism was also observed with Neurospora crassa, Claviceps paspali and four species of Psilocybe. The predominant metabolite formed by most organisms was 1-naphthol. Other products identified were, 4-hydroxy-1-tetralone, trans-1,2-dihydroxy-1,2-dihydronaphthalene, 2-naphthol, 1,2-and 1,4-naphthoquinone.

Abstract  HEEP COPYRIGHT: BIOL ABS. A method for determing the hydrocarbons dissolved in sea water, including their concentration and separation into homogeneous classes, was described. Extraction with organic solvents, determination of the optimum volumes for n-hexane and CCl4 and concentration procedures for the extracts were investigated. Separation of hydrocarbons from polar compounds and their fractionation into 5 classes (aliphatic, monoaromatic and polynuclear with 2, 3-4 and 5-6 rings) were achieved using adsorption chromatography on a 2-step microcolumn of silica gel and aluminium oxide. The overall recovery efficiency of the procedures and the detection limits of several hydrocarbons in 11 sea water were reported.

Abstract  Acute inhalation toxicity was evaluated in groups of 5 male and 5 female Wistar Albino rats exposed to naphthalene at an actual concentration of 77.7 (+/- 1.79) ppm for 4 hours. Mortality was not observed in any animal; the LC50 value was reported to be and gt; 77.7 ppm. Clinical observations included keeping eyes closed, lacrimation and mouth breathing. Gross necropsy revealed no significant lesions.

Abstract  Naphthalene, a derivative of coal tar, is widely used in industry, with little toxic effects. Its ingestion by children, however, may result in a dramatic and occasionally fatal poisioning.