S. Katharine Hammond

Collection and analysis of nicotine as a marker for environmental tobacco smoke

Abstract Nicotine is a potential marker for environmental tobacco smoke (ETS) because it is unique to tobacco smoke and is a major constituent of the smoke. An air sampling method is presented which efficiently collects both particulate and vapor phase nicotine. Two filters are assembled in tandem in a personal sampling cassette. The first filter collects total or size fractional particules and the second is treated with sodium bisulfate to collect vapor phase nicotine and nicotine which has volatilized from the paniculate material collected on the first filler. The nicotine is then desorbed from the filters and analyzed by gas chromatography with nitrogen sensitive detection. The sampling method was evaluated in an environmental chamber under controlled conditions of temperature, humidity, ventilation and smoking rate. It was then employed in a field study of particulate exposures of railroad office workers and railroad mechanics to determine the portion of the particulate exposure attributable to environmental tobacco smoke. The method was found to be efficient and sensitive for the determination of nicotine levels in air.

Exposure Assessment for a Field Investigation of the Acute Respiratory Effects of Metalworking Fluids. I. Summary of Findings

The exposure assessment summarized here is part of an epidemiologic study of the acute respiratory health effects of metalworking fluid (MF) exposures. Exposures were measured as the inhalable concentrations of the MF aerosol, a variety of metals and elements, and endotoxin as well as the level of culturable bacteria in the aerosol size fraction less than 8 microns. Bulk samples of soluble MFs were tested for pH, mineral and tramp oil fraction, endotoxin, culturable bacteria, and lipopolysaccharide levels. The MF exposed workers had higher geometric mean inhalable aerosol exposures (0.181 mg/m3) than the MF unexposed workers (0.046 mg/m3). The MF exposed workers had higher geometric mean (GM) airborne culturable microbial counts (102 colony-forming units (CFU)/m3 for bacteria < 8 microns) than the unexposed workers (GM = 14 CFU/m3). Among the unexposed, Bacillus was the predominant airborne species, while among the exposed workers, Pseudomonas predominated. Exposed workers also had higher geometric mean airborne endotoxin levels (GM = 7.1 endotoxin units (EU)/m3) than the unexposed workers (GM = 1.9 EU/m3). Elemental concentrations of iron, chlorine, and sulfur were substantially higher among the exposed workers compared to the unexposed workers. For soluble metalworking fluids, the levels of bulk constituents were examined by three categories of time since the machine sump was refilled with fresh MF (< 4 days, 4-21 days, > 21 days). Univariate analyses of percent oil, pH, culturable bacteria, tramp oil percent, endotoxin, or fatty acid levels all showed no statistically significant changes in level over time.

Factors Affecting Worker Exposures to Metal-Working Fluids During Automotive Component Manufacturing

Abstract A two-stage personal impactor was used to collect fullshift exposure measurements of metal-working fluid exposures from workers in three automotive component manufacturing facilities. The 403 workers exposed to metal-working fluid in machining and grinding operations had an average total particulate exposure of 706 μg/m3 (standard error = 21 μg/m3). For a subset of 309 workers, information on factors that might influence the exposure level was also collected. This information included the metal-working fluid type, the machine type, the presence of local exhaust, the degree of machine enclosure, the age of the machine, the distance of the worker from the machine, and the indoor and outdoor temperature and humidity. Statistical analysis was used to investigate which factors contribute most significantly to the variability in exposures to large (> 9.8 μm aerodynamic diameter) and small (<3.5 μm) particles. For large particles, the factors of greatest importance in a stepwise analysis of covariance (...

Measurement of cabin air quality aboard commercial airliners

Abstract Between April and June 1989, 92 randomly selected flights were monitored to determine prevailing levels of environmental tobacco smoke (ETS) and other pollutants in the airliner cabin environment. The monitored flights included 69 smoking flights, 8 of which were international, and 23 nonsmoking flights, all of which were domestic. Selected ETS contaminants (nicotine, respirable suspended particles and carbon monoxide), as well as ozone, microbial aerosols, carbon dioxide and other environmental variables were measured in different parts of airliner cabins. Particle and nicotine concentrations were highest in the smoking section and were somewhat higher in the boundary region near smoking than in other no-smoking sections or on nonsmoking flights. Levels of these ETS tracers were correlated with smoking rates observed by field technicians, and their levels in the boundary section were higher when more proximate to the smoking section. CO 2 levels were sufficiently high and humidity levels were sufficiently low to pose potential comfort problems for aircraft occupants. Ozone levels were well within existing standards for airliner environments, and levels of microbial aerosols were below those in residential environments that have been characterized through cross-sectional studies.

Measuring personal exposure to airborne mutagens and nicotine in environmental tobacco smoke

The exposure of individuals to environmental tobacco smoke (ETS) is of increasing public health concern because epidemiological studies have associated passive smoking with increased risk of a variety of adverse health effects among non-smokers including lung cancer. As a way to measure individual exposure to the mutagenic compounds in the complex mixture of ETS, we used a sensitive Salmonella/microsome micro pre-incubation (microsuspension) assay to detect mutagenicity of particulate matter collected on filters from low volume (1.7 1/min flow rate) personal sampling pumps. Airborne nicotine was collected concurrently as a marker for ETS exposure. In pilot-field studies, individual exposure to ETS was measured in two separate indoor environments in which smokers were present: a gambling casino and a bingo parlor. Total suspended particulate matter (TSP) was collected on filters worn near the breathing zone of non-smoking individuals. Sampling times ranged from 40 min to 6 h. All extracts of filters had detectable levels of mutagenic activity (TA98, +S9) resulting in airborne mutagenic activity concentrations of 500-5000 rev/m3. The mutagenic activity of the filters from the casino and bingo parlors was significantly correlated with total particulate matter per filters (n = 12; Rho = 0.85, p less than 0.01) and with airborne nicotine per filter (n = 12; Rho = 0.95, p less than 0.01). The microsuspension assay was sufficiently sensitive to detect the mutagens associated with extracts of particulate matter from low volume samples (0.2-0.6 m3) in these indoor environments over a relatively short sampling time, and could be useful in studies of personal exposure to the mutagens in environmental tobacco smoke. Further, airborne nicotine concentrations were highly correlated with airborne mutagenicity and the mutagenic activity associated with ETS could therefore be estimated by the concentrations of nicotine.

Exposure Assessment for Epidemiology: Characteristics of Exposure

Abstract Estimation of past exposures to potential health hazards is one of the most difficult problems for industrial hygiene research. Although it is very difficult, it is not impossible. There are two conceptual models that can guide the hygienist in this task: the source-receptor model and the task-TWA (time-weighted average) model of full-shift exposures. The source-receptor model is a formalization of the professional decision criteria used by hygienists in their initial assessments of a workplace to identify where hazards might exist and where to sample. Thus, by performing a detailed assessment of the nature of past operations, raw materials, and job activities, it is frequently possible to identify where exposures might have occurred and what agents might have been involved. The task-TWA model is useful for developing historical estimates of full-shift exposures by integrating information on changes in job activities with limited monitoring data. It is particularly useful for extrapolating TWA ex...

Markers of Exposure to Diesel Exhaust and Cigarette Smoke in Railroad Workers

Diesel exhaust is a complex mixture of combustion gases, vapors and particles, and personal exposure can be estimated indirectly only. Quantitative estimates of exposure were developed for thirteen job groups in a large epidemiologic study of mortality among railroad workers. Three possible markers of exhaust exposure were developed. The first index was the concentration of respirable particles because this was simple and inexpensive to measure precisely. Major positive interference, however, was found from environmental tobacco smoke (ETS) and inorganic respirable particles from other emission sources. Composited job group samples were analyzed for particulate nicotine so the ETS component could be subtracted from the respirable particle concentration. This produced a second exposure index, the adjusted respirable particle concentrations. Since there are nondiesel sources of particles in some work areas, a third marker was sought. Diesel exhaust particles have a relatively high content of dichloromethane extractable matter, but inorganic particles have a low extractable content. Therefore, the air concentration of extractable mass was used as a third marker of diesel exposures. The extractable matter also was corrected for the contribution of ETS. The advantages and limitations of these three markers are of interest. In general, considerable caution should be used in the development and application of markers; their use requires detailed knowledge of the nature and sources of exposure in a given setting.

Assessment of Task and Peak Exposures to Solvents in the Microelectronics Fabrication Industry

Abstract Short-term exposures to six solvents used in microelectronic fabrication clean rooms were assessed. The solvents measured were: 2-ethoxyethylacetate, n-butyl acetate, xylene, isopropanol, acetone, and propylene glycol monomethylether acetate. Short-term exposures during production and maintenance tasks were measured using both charcoal tubes to obtain average task exposures and direct reading instrumentation to obtain real-time peak levels. All measured samples were considerably below current government or consensus standards for short-term exposures. Pharmacokinetic modeling was used to evaluate the toxicological significance of the highest real-time peaks measured, which in these clean rooms were to the solvent acetone. The model suggested that the peaks measured were below acetone levels associated with reproductive health risks in animals. Hallock, M.F.; Hammond, S.K.; Kenyon, E.; Smith, T.J.; Smith, E.R.: Assessment of Task and Peak Exposures to Solvents in the Microelectronics Fabrication I...

Ethanolamine Exposures of Workers Using Machining Fluids in the Automotive Parts Manufacturing Industry

Abstract Ethanolamines (EAs) are present in machining and grinding fluids and have the potential to act as respiratory irritants and sensitizing agents. EA levels in bulk cutting fluids were determined and compared with information available in the material safety data sheets (MSDSs), and the exposure to EAs of workers in the auto parts manufacturing industry was characterized. Monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) were all present in bulk machining fluids at levels ranging from 1 percent to 11 percent, 4 percent to 5 percent, and 0.3 percent to 40 percent, respectively. The MSDSs provided a general guideline to the presence or absence and relative levels of alkanolamines as a class, but were not generally useful as a guide to the presence or relative amount of specific EAs. This was particularly the case with MEA. Air levels of TEA in the personal samples were generally higher for transfer operations and lowest for assembly workers, who do not use machining fluids in the...

Railroad diesel exhaust: Concentration and mutagenicity

Abstract High volume fixed location samples of particles and vapor phase components were collected on filters and XAD-2 resin, respectively, to study the concentration and mutagenicity of diesel exhaust in locomotive repair shops at four railroads. The geometric mean concentrations were 96 μg/m3 [geometric standard deviation (GSD) = 2.14] for 23 samples of respirable particles, 164 μg/m3 (GSD = 1.86) for 26 samples of total particles, and 432 μg/m3 for 9 samples of vapor phase components. Approximately 30 to 40 percent of the particle mass was extractable in dichloromethane. Chemical class separation of these extracts by normal phase liquid chromatography yielded nearly half the mass in the aliphatic fraction, less than one third in the aromatic fraction, and about one quarter in the polar fraction. Extracts of particle samples were found to be mutagenic in the Salmonella typhimurium forward mutation assay system. Most of this activity was in the polar fraction. None of the vapor phase samples tested cont...