The objective of this investigation was to determine the extent of areal and day-to-day variability of stationary environmental tobacco smoke (ETS) concentrations in a single large facility where smoking was both prevalent and unrestricted, and to determine the degree of daily variation in the personal exposure levels of ETS constituents in the same facility. The subject facility was a relatively new four-story office building with an approximate volume of 1.3 million ft 3 . The exchange of outside air in the building was determined to be between 0.6 and 0.7 air changes per hour. Eighty-seven area samples (excluding background) were collected at 29 locations over the course of 6 days of sampling. Locations included offices and cubicles occupied by smokers and nonsmokers, common areas, and the computer and mail rooms. Twenty-four nonsmoking subjects wore personal sampling systems to collect breathing zone air samples on each of 3 days in succession. This generated a total of seventy-two 8-h time-weighted average (TWA) personal exposure samples. In all samples, respirable suspended particulate matter, ultraviolet light-absorbing and fluorescing particulate matter, solanesol, nicotine, and 3-ethenyl pyridine were determined. With the exception of a few locations, tobacco-specific airborne constituents were determined in all samples. Not surprisingly, areas with the highest ETS constituent concentrations were offices and cubicles of smokers. Median and 95th percentile concentrations for all area samples, excluding background, were determined to be 1.5 and 8.7 μg/m 3 for nicotine, and 8.2 and 59 μg/m 3 for ETS-specific particles (as solanesol-related particulate matter, Sol-PM), respectively. Personal exposure concentrations of ETS components were similar to those levels found in the area samples (median nicotine and Sol-PM concentrations were 1.24 and 7.1 μg/m 3 , respectively), but the range of concentrations was somewhat smaller. For example, the 95th percentile 8-h TWA nicotine and ETS-specific particle (as Sol-PM) concentrations were 3.58 and 21.9 μg/m 3 , respectively. Intrasubject variation of daily concentrations ranged from 20% to 60%, depending on the component. Self-reported proximity to smokers was supported by higher ETS concentrations determined from the personal monitors, but only to a modest extent. Although smoking was completely unrestricted inside the main office areas of the facility, ETS levels, either areal or from personal exposure measurements, were lower than those estimated by Occupational Safety and Health Administration to be present in such facilities.

Elution of a nonpolar stationary (reversed)-phase C18 column with 40% (v/v) acetonitrile in water, buffered with sodium acetate—acetic acid at pH 4.6, produced good resolution of several low-molecular-weight hydroxybenzenes including phenol, o-cresol, m + p-cresol, resorcinol, catechol, and hydroquinone. The unique fluorescent characteristics of hydroxybenzenes enhanced both selectivity and detection limits and facilitated the quantitative estimation of these compounds in a complex mixture after a simple extraction followed by isocratic elution. The determinations can be made within a 24-h period and require small amounts of sample-handling and personnel time. Applications of this scheme to the quantitation of hydroxybenzenes in fossil fuel-derived liquids and associated process waters are described.

In order to demonstrate quantitatively that cigarette-smoking baboons inhale particulate matter into the lung, a bronchoalveolar lavage method for recovery of [14C]dotioacontane was developed. First, 9 baboons were exposed to a known dose of [14C]dotriacontane labeled particulate matter delivered in a manner providing extensive deposition of particulates in the lung. The lungs of these passively exposed animals then were lavaged so that the efficiency of recovery of the standardized lavage procedure could be determined. Second, 9 baboons actively smoked labeled cigarettes, and the lungs of these animals were lavaged to recover labeled [14C]dotriacontane. The total amount of particulate matter present in the lungs was estimated using the efficiency factor previously determined. The smoking baboons retained an average of 9% of the total cigarette particulate matter. Differences among animals in retention of particulate matter were considerable, and the inter-animal variability was related to differences in number, volume, duration, and pressure of puffs. The retention of particulate matter by baboons is similar to particulate retention by other animal smoke inhalation models.

SUMMARY A methodwas developedfor continuouslyexposingtra cheal epithelium to measured amounts of carcinogen. Beeswax was the vehicle for sustained release of carcino gen, and tracheas transplanted to s.c. sites were target tissues. In the experiment reported here, transplanted rat tracheas were exposed to a potent carcinogen, 7,12-di methylbenz(a)anthracene (DMBA). The rate of release of DMBA from the beeswax carrier within the tracheal lumen approached first order when the initial concentration of carcinogen was high (3200to 325 j@g in a 24.45-mg pellet). With lower concentrations, where the carcinogen was dissolved in the beeswax, initial release was rapid,and mostof the carcinogenwasdeliveredwithin 4 weeks. At high DMBA dose levels, the entire tracheal epithelium was uniformly replacedby keratinizingsquamousmetapla sia after 1 week of exposure, and after 2 months, when from 280 to 910 @g DMBA had been delivered, all transplants had developedinvasivesquamouscarcinomas.Sarcomasalso developed in 19% of the transplants. At lower dose levels the epithelial reactions were more varied, and tumor development was more protracted. The lowest DMBA dose presently known to induce carcinomas in this experimental model is 40 ;Lg, which is in the dose range used for tumor initiation in skin carcinogenesis studies in mice.

SUMMARY Amethodwasdevelopedforcontinuouslyexposingtrachealepitheliumtomeasuredamountsofcarcinogen. Beeswaxwasthevehicleforsustainedreleaseofcarcinogen,andtracheastransplantedtos.c.sitesweretargettissues.Intheexperimentreportedhere,transplantedrattracheaswereexposedtoapotentcarcinogen,7,12-dimethylbenz(a)anthracene(DMBA).TherateofreleaseofDMBAfromthebeeswaxcarrierwithinthetracheallumenapproachedfirstorderwhentheinitialconcentrationofcarcinogenwashigh(3200to325j@gina24.45-mgpellet).Withlowerconcentrations,wherethecarcinogenwasdissolvedinthebeeswax,initialrelease wasrapid,andmostofthecarcinogenwasdeliveredwithin4weeks. AthighDMBAdoselevels,theentiretrachealepithelium wasuniformlyreplacedbykeratinizingsquamousmetapla sia after1weekofexposure,and 2months,whenfrom280to910@gDMBAhadbeendelivered,alltransplantshad developedinvasivesquamouscarcinomas.Sarcomasalso developedin19%ofthetransplants.Atlowerdoselevelstheepithelialreactionsweremorevaried,andtumordevelopmentwasmoreprotracted.ThelowestDMBAdosepresentlyknowntoinducecarcinomasinthisexperimentalmodelis40;Lg,whichisinthedoserangeusedfortumorinitiationinskincarcinogenesisstudiesinmice.INTRODUCTIONAmajorlimitationofmostrespiratorycarcinogenesisstudiesisthatthecommonlyusedexperimentalmodelsdonotpermitdeliveryofaknownamountofcarcinogentoatargetofpredeterminedsizeinatopographicallydefinedregionoftherespiratorytract.Afteracarcinogenisadministeredi.t.3orbyinhalationexposure,itisdistributedun

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrogen bonding in some copper(II) and nickel(II) vic-dioximesJohn E. Caton Jr. and Charles V. BanksCite this: Inorg. Chem. 1967, 6, 9, 1670–1675Publication Date (Print):September 1, 1967Publication History Published online1 May 2002Published inissue 1 September 1967https://doi.org/10.1021/ic50055a013RIGHTS & PERMISSIONSArticle Views183Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (616 KB) Get e-Alerts Get e-Alerts

The ultraviolet and visible spectra of copper dimethyl-glyoxime exhibit significant shifts as the solvent medium is varied; no such changes were observed for nickel dimethylglyoxime and nickel ethylmethylglyoxime. The observed variations in the metal-to-ligand charge transfer bands for copper dimethylglyoxime are attributed to slight changes in the nature of the Cu-N bonds; the absence of such changes in the corresponding band in nickel dimethylglyoxime is taken to indicate an insignificant variation in the Ni-N bonds of the two chelates of nickel in different solvents. The presence of small amounts of n-butylamine changed the spectra of copper dimethylglyoxime very significantly while 100-fold excesses of n-butylamine did not alter the spectra of the chelates of nickel. These changes in the spectra of copper dimethylglyoxime were used to establish the assignment of the metal-to-ligand charge transfer band. Finally, in agreement with other investigators, it is concluded that the difference in solubility between copper dimethylglyoxime and nickel dimethylglyoxime in polar solvents is due to the greater tendency of copper dimethylglyoxime to complex with solvent molecules. The higher solubility of nickel ethylmethyl-glyoxime in organic solvents is attributed to stronger crystal forces in both nickel dimethylglyoxime and copper dimethylglyoxime. The stronger forces in copper dimethylglyoxime are due to the well-established Cu-O bonds, and the stronger forces in nickel dimethylglyoxime are attributed to Ni-Ni interactions.