Joan M. Daisey

Profiles of Organic Particulate Emissions from Air Pollution Sources: Status and Needs for Receptor Source Apportionment Modeling

Trace elements are widely used to identify the sources of airborne pollutants and to apportion their contributions to the ambient aerosol through receptor models. Due to the impending loss of Pb and Br as automotive emissions tracers and our inability to distinguish among certain types of emissions using tracer elements, there is a need to identify alternative emissions tracers. Organic compounds may also be useful tracers for sources of particles or toxic air pollutants which do not emit trace metals. Published data on the organic composition of source emissions were reviewed to determine their usefulness for these purposes. Factors affecting the variability of reported organic emissions source profiles have been discussed in detail in this review. The existing data indicate that it may be possible to use polycyclic aromatic hydrocarbons, alkanes and certain apparently unique organic compounds to assist in distinguishing among emissions from certain particulate pollutant sources. These compounds can prob...

Polycyclic aromatic hydrocarbons and total extractable particulate organic matter in the Arctic aerosol

Abstract Samples of total suspended paniculate matter were collected in March and August 1979 at Barrow, Alaska, a remote site in the Arctic. Ambient concentrations of extractable paniculate organic matter (POM), of polycyclic aromatic hydrocarbons (PAH) and of 210 Pb were determined. The samples were also examined by optical and scanning electron microscopy. Average concentrations of POM and PAH were similar to those reported for other remote sites in the northern hemisphere, but the concentrations were considerably higher in March than in August. The presence of fly ash in the samples collected during the March sampling period, as well as seasonal differences in the concentrations of the organic species and 210 Pb and in meteorology indicate that the principal source of POM and PAH was fossil fuel combustion in the mid-latitudes during the March sampling period.

An Exploratory Analysis of the Relationship Between Mortality and the Chemical Composition of Airborne Particulate Matter.

We explored relationships between daily mortality and the major sources of airborne particulate matter (PM) using a newly developed approach, Factor Analysis and Poisson Regression (FA/PR). We hypothesized that by adding information on PM chemical speciation and source apportionment to typical PM epidemiological analysis, we could identify PM sources that cause adverse health effects. The FA/PR method was applied to a merged data set of mortality and extensive PM chemical speciation (including trace metals, sulfate, and extractable organic matter) in New Jersey. Statistically significant associations were found between mortality and several of the FA-derived PM sources, including oil burning, industry, sulfate aerosol, and motor vehicles. The FA/PR method provides new insight into potentially important PM sources related to mortality. For the data set we analyzed, the use of FA/PR to integrate multiple chemical species into source-related PM exposure metrics was found to be a more sensitive tool than the traditional approach using PM mass alone.

Polycyclic aromatic hydrocarbons in New Jersey: A comparison of winter and summer concentrations over a two-year period

Abstract Polycyclic aromatic hydrocarbons (PAH) have been analysed from inhalable airborne particulate matter collected at four New Jersey locations during four 6-week periods (Summer 1981, Winter 1982, Summer 1982 and Winter 1983). The sites included three urban locations (Newark, Elizabeth and Camden) and one rural site (Ringwood). The analytical methodology involved soxhlet extraction of preheated glassfiber filters with cyclohexane, thin-layer chromatography and ultimate analysis using reverse-phase highperformance liquid chromatography and ultraviolet and fluorescence detection. The quality assurance/quality control procedure is described. Discussions of differences in PAH levels between urban and rural sites as well as the summer/winter differences in concentrations rely upon consideration of sources as well as differences in PAH reactivities. Comparisons of PAH levels are also made between pollution episode and non-episode periods. In addition intra- and intersite correlations between PAHs as well as other pollutants are discussed. Profiles of PAH do not appear to differ significantly between the few sites during a given season.

Elevated symptom prevalence associated with ventilation type in office buildings

&NA; The California Healthy Building Study was designed to assess relations between ventilation system type and office worker symptoms in a set of U.S. buildings selected without regard to worker complaints. Twelve public office buildings in northern California meeting specific eligibility criteria were studied in the summer of 1990: three naturally ventilated, three mechanically ventilated (without air conditioning), and six air‐conditioned buildings. Questionnaire data were collected from 880 workers in selected spaces within the study buildings. We adjusted effect estimates for various ventilation types for personal, job, and work place factors using logistic regression, and alternatively, using a mixed effects model (SAS/GLIMMIX) to adjust for correlated responses within study spaces. Higher adjusted prevalences of most symptom outcomes were associated with both mechanical and air‐conditioned ventilation, relative to natural. With a conservative adjustment for problem building status, the highest adjusted prevalence odds ratios from logistic regression models were for dry or itchy skin [mechanical: odds ratio (OR) = 6.0, 95% confidence interval (CI) = 1.6‐22; air‐conditioned: OR = 6.0, 95% CI = 1.7‐21] and lower respiratory symptoms (mechanical: OR = 2.9, 95% CI = 0.7‐11; air‐conditioned: OR = 4.0, 95% CI = 1.1‐15). GLIMMIX estimates were similar, with slightly wider confidence intervals. Reporting bias was small. These findings of symptom increases within mechanically ventilated and airconditioned U.S. buildings support previous findings available only from European buildings. (Epidemiology 1996;7:583‐589)

Use of volatile tracers to determine the contribution of environmental tobacco smoke to concentrations of volatile organic compounds in smoking environments

Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, were investigated as potential tracers for determining the contribution of environmental tobacco smoke (ETS) to concentrations of volatile organic compounds (VOCs) in indoor environments with smoking. The source emission rates of the three tracers and ten selected VOCs in ETS were first measured in a room-size environmental chamber for a market-weighted selection of six commercial cigarettes. The ratios of the emission rates of the tracers to the emission rates of the selected VOCs were calculated and compared among the six brands. The utility of the tracers was then evaluated in a field study conducted in five office buildings. Samples for VOCs were collected in designated smoking areas and adjoining non-smoking areas, air change rates were measured, and smoking rates were documented. Concentrations of the three tracers in the smoking areas were calculated using a mass-balance model and compared to their measured concentrations. Based on this comparison, 3-EP was selected as the most suitable tracer for the volatile components of ETS, although pyrrole is also potentially useful. Using 3-EP as the tracer, the contributions of ETS to the measured concentrations of the selected VOCs in the smoking areas were estimated by apportionment. ETS was estimated to contribute 57 to 84 percent (4.1 to 26 pg m{sup -3}) of the formaldehyde concentrations, 44 to 69 percent (0.9 to 5.8 pg m{sup -3}) of the 2-butanone concentrations, 37 to 58 percent (1.3 to 8.2 pg m{sup -3}) of the benzene concentrations, and 20 to 69 percent (0.5 to 3.0 pg m{sup -3}) of the styrene concentrations. The fractional contributions of ETS to the concentrations of acetone, toluene, ethylbenzene, xylene isomers and d-limonene were all less than 50 percent.

Seasonal variations in the bacterial mutagenicity of airborne particulate organic matter in New York City

Seasonal composites of three fractions of particulate organic matter collected from New York City air were tested for direct-acting (no microsomal activation) bacterial mutagenicity by using the Ames bioassay. Winter maxima in the activity per cubic meter of air were found for the polar fraction with Salmonella typhimurium TA-98 and TA-100. The nonpolar and moderately polar fractions exhibited fall-winter rather than distinct winter maxima. These results and a consideration of the principal sources of particulate organic matter indicate that fuel-oil combustion for space heating contributes approximately half of the observed activity per cubic meter in New York City in the winter. Space heating is probably a significant source of these biologically active materials in other northeastern US . cities as well. Sources which do not exhibit strong seasonal patterns, such as automobiles, must also contribute to the observed activity as biologically active organic matter is present in the aerosol in all seasons.

Sources and Source Strengths of Volatile Organic Compounds in a New Office Building

This study was conducted at a newly constructed federal office building in Portland, Oregon. The primary objectives were to identify the major sources of volatile organic compounds (VOC) in the building and to measure both long-term (one year) and short-term (several day) variations in concentrations and source strengths. Samples for VOC were collected on four occasions over a period of 14 months starting with the first month of occupancy. During the final sampling period, samples were collected over four days (Friday - Monday). The samples were analyzed for individual compounds and for total VOC (TVOC). The results were expressed as specific source strengths, as well as concentrations, to facilitate comparisons of measurements made under different ventilation conditions. The primary source of VOC in the building was identified as liquid-process photocopiers and plotters which emitted a characteristic mixture of C10-Cn isoparaffinic hydrocarbons. The specific source strength of TVOC, which was dominated b...

Semivolatile and particulate polycyclic aromatic hydrocarbons in environmental tobacco smoke. Cleanup, speciation, and emission factors

Studies of phase distributions and emission factors for polycyclic aromatic hydrocarbons (PAH) in environmental tobacco smoke (ETS) require collection and analysis of very small samples. To achieve the necessary selectivity and sensitivity, a method has been devised and tested for extraction and cleanup of gas- and particulate-phase ETS samples. Gas-phase species were trapped by polymeric sorbents, and particles were trapped on filters. The samples were extracted with hot cyclohexane, concentrated and passed through silica solid-phase extraction columns for cleanup. After solvent change, the PAH were determined by high performance liquid chromatography with two programmed fluorescence detectors. PAH concentrations in 15-mg aliquots of National Institute of Standards and Technology Standard Reference Material SRM 1649 (Urban DustIOrganics) agreed well with published values. Relative precision at the 95% confidence level was 8% for SRM 1649 and 20% for replicate samples (5 mg) of ETS particles. Emission factors have been measured for a range of gas- and particulate-phase polycyclic aromatic hydrocarbons in ETS. The emission factors per cigarette were 13.0{+-}0.5 mg particulate matter, 11.2{+-}0.9 pg for gas-phase naphthalene and 74{+-}10 {micro}g for particulate benzo(a)pyrene.

Considerations for design of source apportionment studies

This report recommends procedures for source and ambient sampling and analysis in source apportionment studies. The recommendations are based on the results of receptor model studies of atmospheric particles in urban areas, especially a recent study of Houston, TX, undertaken as part of the Mathematical and Empirical Receptor Models Workshop (Quail Roost II). The recommendations are presented at three levels of increasing cost and detail of information obtained. Existing mass emissions inventories combined with chemically resolved test data from similar sources (not necessarily in the same locale) can be used to initially estimate the sources of elements present on ambient particles. To aid local users in construction of chemically resolved emission estimates, the U.S. Environmental Protection Agency (EPA) is compiling a library of compositions and size distributions of particulate emissions from major source types. More reliable source characterization can be achieved if the actual sources are tested directly. EPA should develop and publish detailed procedures for source sampling that would be more appropriate for receptor model use than are existing standard methods. Source and ambient sampling should be conducted by similar methods. If possible, particles from sources should be collected in a way that simulates changes that would normally occur before they reach distant receptors (e.g. by diluting and cooling the particles from hot sources). It is recommended that particulate samples be routinely collected in two size fractions by use of virtual impactors and that all samples be subjected, at a minimum, to mass and X-ray fluorescence analyses. Additional measurements are suggested for obtaining more detailed information: neutron activation analysis; X-ray diffraction; automated particle classification by electron microscopy; analyses for classes of organic species, ^(14)C and thermally released carbonaceous species; and real-time observation of several gases during sample collection. Methods for collecting meteorological data in parallel with ambient samples are described, as are methods for incorporating such data into the source identification process.