Environmental tobacco smoke in an unrestricted smoking workplace: area and personal exposure monitoring.

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 ft3. 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 microg/m3 for nicotine, and 8.2 and 59 microg/m3 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 microg/m3, 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 microg/m3, 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.

Characterization of mutagenic coal fly ash and extracts.

Post-electrostatic precipitator (ESP) fly ash samples were collected from a coal-fired electric power generation plant under three modes of plant operation: normal operation, a low NOx-emission mode of combustion, and operation with the ESP shorted-out. Results of chemical and physical characterization of the ashes were compared with bacterial mutagenicity bioassay to determine parameters or compounds correlating with bioactivity. The general physical properties, ultimate composition, and trace elemental and radiochemical species determined did not correlate with the mutagenicity. Only the presence of aromatic hydrocarbons and chemically derivatizable polar organic compounds appeared to be associated with mutagenicity of the fly ash.

Cigarette smoking by baboons: in vivo assessment of particulate inhalation using bronchoalveolar lavage to recover [14C]dotriacontane.

In order to demonstrate quantitatively that cigarette-smoking baboons inhale particulate matter into the lung, a bronchoalveolar lavage method for recovery of [14C]dotriacontane 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 he 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.

Chronic inhalation of cigarette smoke by F344 rats.

Specific-pathogen-free female F344 rats were exposed by inhalation to what was considered a maximal tolerated dose of cigarette smoke. Total pulmonary deposition of smoke particulates from a single cigarette was 0.25 mg in young rats. Rats were exposed to smoke from 7 cigarettes/day for as long as 2.5 years, at which time 30% of the rats remained alive. Mortality of smoke-exposed animals was not different from that of untreated or sham-exposed controls. Hyperplastic and metaplastic areas in the epithelium of the nasal turbinates, larynges, and tracheae of exposed animals were observed at death. The lungs of exposed rats contained areas of focal alveolitis consisting of accumulated pigmented macrophages, epithelial hyperplasia, fibrosis, and disrupted alveolar structure. Smoke exposure did not change the total number of tumor-bearing animals relative to controls; however, exposed rats had significantly fewer tumors in the hypophyses, hematopoietic-lymphoid systems, uteri, and ovaries but an increased number of tumors in the respiratory tracts and dermes. Only 1 of 93 (1%) control rats had a tumor (an alveologenic carcinoma) in the respiratory tract as opposed to 7 of 80 (9%) exposed animals (nasal tumors: 1 adenocarcinoma and 1 squamous cell carcinoma; pulmonary tumors: 5 adenomas, 2 alveologenic carcinomas, and 1 squamous carcinoma).

Induction of preneoplastic and neoplastic lesions in grafted rat tracheas continuously exposed to benzo(a)pyrene.

Heterotopically transplanted rat tracheas were continuously exposed to measured amounts of benzo(a)pyrene over a period of 1 to 6 months. The cumulative doses ranged from 10 to 2490 microng. The morphological response of the tracheal epithelium was characterized by hyperplasis during the first 2 weeks, followed by atrophy. Squamous metaplasias did not appear until after 4 months of exposure; at 4 and 6 months numerous dysplastic lesions and noninvasive carcinomas resembling those seen in the airways of humans were found in the higher carcinogen dose groups. The first invasive carcinomas developed at 4 months in the groups given 1250 microng or more benzo(a)pyrene. The lowest dose tested that produced a carcinoma within the observation period of 22 months was 300 microng benzo(a)pyrene. The majority of the neoplasms were squamous cell carcinomas, although several adenocarcinomas and sarcomas also developed. Since a variety of metaplastic and dyplastic lesions can be induced by carcinogenic polycyclic hydrocarbons in the transplanted rat tracheas, this experimental model appears to be well suited for the study of the sequential epithelial changes that lead to respiratory tract neoplasia.

Quantitative exposure of grafted rat tracheas to 7, 12-dimethylbenz(a)anthracene.

A method was developed for continuously exposing tracheal epithelium to measured amounts of carcinogen. Beeswax was the vehicle for sustained release of carcinogen, 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-methyl benz(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 (3200 to 325 microng in a 24.45-mg pellet). With lower concentrations, where the carcinogen was dissolved in the beeswax, initial release was rapid, and most of the carcinogen was delivered within 4 weeks. At high DMBA dose levels, the entire tracheal epithelium was uniformly replaced by keratinizing squamous metaplasia after 1 week of exposure, and after 2 months, when from 280 to 910 microng DMBA had been delivered, all transplants had developed invasive squamous carcinomas. Sarcomas also 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 diduce carcinomas in this experimental model is 40 microng, which is in the dose range used for tumor initiation in skin carcinogenesis studies in mice.

Early detection of pregnancy-associated serum protein using antiserum to placental antigens.

Antisera against human placental proteins were developed in goats and rabbits, using immunoadjuvants and a prolonged injection schedule. The antisera were absorbed with normal serum proteins and then tested in immunodiffusion against normal and pregnancy sera. Two bands of precipitation due to pregnancy antigens were observed in pregnancy sera as early as 18 days after conception. Detection of these antigens has possibilities for application as an early pregnancy test.

Studies of the spectra of copper dimethyl-glyoxime, nickel dimethylglyoxime and nickel ethylmethylglyoxime in various solvents.

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.