Indoor/Outdoor Air Pollution Exposure Continuity Relationships

The indoor/outdoor air pollution exposure continuity relationships are considered in an attempt to define the major parameters determining the relation. The widely accepted hypothesis of a homeostatic balance between indoor and outdoor pollutant levels has been disclaimed using particulate lead as an index contaminant. A serial filtration collection technique was employed and analysis was performed by atomic absorption spectrophotometry. The results of this study demonstrate the importance of considering parameters other than outdoor pollutant levels in determining indoor air quality.     

Personal Exposure to Fine Particulate Matter in Elderly Subjects: Relation between Personal,Indoor, and Outdoor Concentrations

ABSTRACT

The time-series correlation between ambient levels, indoor levels, and personal exposure to PM_2.5 was assessed in panels of elderly subjects with cardiovascular disease in Amsterdam, the Netherlands, and Helsinki, Finland. Subjects were followed for 6 months with biweekly clinical visits. Each subject's indoor and personal exposure to PM_2.5 was measured biweekly, during the 24-hr period preceding the clinical visits. Outdoor PM_2.5 concentrations were measured at fixed sites. The absorption coefficients of all PM_2.5 filters were measured as a marker for elemental carbon (EC). Regression analyses were conducted for each subject separately, and the distribution of the individual regression and correlation coefficients was investigated. Personal, indoor, and ambient concentrations were highly correlated within subjects over time. Median Pearson's R between personal and outdoor PM_2.5 was 0.79 in Amsterdam and 0.76 in Helsinki. For absorption, these values were 0.93 and 0.81 for Amsterdam and Helsinki, respectively. The findings of this study provide further support for using fixed-site measurements as a measure of exposure to PM_2.5 in epidemiological time-series studies.     

A Movable Laboratory for Controlled Clinical Studies of Air Pollution Exposure

The cause of the Yokkaichi asthma episode (1960-1969) has been analyzed. It Is concluded that the respiratory diseases were due not to sulfur dioxide but to concentrated sulfuric acid mists emitted from stacks of calciners of a titanium oxide manufacturing plant located windward of the residential area.     

Exposure of Chronic Obstructive Pulmonary Disease Patients to Particulate Matter: Relationships between Personal and Ambient Air Concentrations

ABSTRACT

Most time-series studies of particulate air pollution and acute health outcomes assess exposure of the study population using fixed-site outdoor measurements. To address the issue of exposure misclassification, we evaluate the relationship between ambient particle concentrations and personal exposures of a population expected to be at risk of particle health effects.

Sampling was conducted within the Vancouver metropolitan area during April-September 1998. Sixteen subjects (non-smoking, ages 54-86) with physician-diagnosed chronic obstructive pulmonary disease (COPD) wore personal PM_{2 5} monitors for seven 24-hr periods, randomly spaced approximately 1.5 weeks apart. Time-activity logs and dwelling characteristics data were also obtained for each subject. Daily 24-hr ambient PM₁₀ and PM_2.5 concentrations were measured at five fixed sites spaced throughout the study region. SO₄ ^2-, which is found almost exclusively in the fine particle fraction and which does not have major indoor sources, was measured in all PM_{2 5} samples as an indicator of accumulation mode particu-late matter of ambient origin.     

Estimating Separately Personal Exposure to Ambient and Nonambient Particulate Matter for Epidemiology and Risk Assessment: Why and How

ABSTRACT

This paper discusses the legal and scientific reasons for separating personal exposure to PM into ambient and nonambient components. It then demonstrates by several examples how well-established models and data typically obtained in exposure field studies can be used to estimate both individual and community average exposure to ambient-generated PM (ambient PM outdoors plus ambient PM that has infiltrated indoors), indoor-generated PM, and personal activity PM. Ambient concentrations are not highly correlated with personal exposure to nonambient PM or total PM but are highly correlated with personal exposure to ambient-generated PM. Therefore, ambient concentrations may be used in epidemiology as an appropriate surrogate for personal exposure to ambient-generated PM. Suggestions are offered as to how exposure to ambient-generated PM may be obtained and used in epidemiology and risk assessment.     

Some Applications of Microscopy to Air Pollution

The microscope as it has been and is now applied to air pollution work is discussed. A summary of the most common particulate sampling equipment is presented and distinctions as to the area of usage (suspended, or settled particulates) are made in each instance. Actual cases are discussed in which the polarizing microscope was used to determine identities and source of particulate pollutants. Particles from such sources as power plants, feed mills, and combustion sources are discussed and photomicrographs of known samples and unknown particles causing complaints are presented and compared as part of the discussion. References are given which deal with sampling equipment and microscopic analysis of various particulates.     

Air Pollution and Mortality: The Implications of Uncertainties in Regression Modeling and Exposure Measurement

In a previous paper,¹ we showed that the mean effects on daily mortality associated with air pollution are essentially the same for gases and particulate matter (PM) and are invariant with respect to particle size and composition, based on 27 statistical studies that had been published at that time. Since then, a new analysis² reported stronger mortality associations for the fine fractions of PM obtained from dichotomous samplers, relative to the coarse fractions. In this paper, we show that differential measurement errors known to be present in dichotomous sampler data preclude reliable determination of such statistical relationships by particle size. Further, it is necessary to consider gaseous pollutants simultaneously with particles to provide robust estimates of the responsibilities for the implied daily mortality gradients. Finally, certain regression model specifications may be sensitive to differences in frequency distribution characteristics according to particle size.     

Interactions of Environmental Factors on the Sensitivity of Plants to Air Pollution

Before potential damage to vegetation can be adequately forecast, even after an air pollution alert has been placed in effect, a clear understanding of the interactions of environment on plant sensitivity must be ascertained. This involves detailed study of single factors and then multiple factors using the phytotoxicants in question. Factors studied or suggested include light (quality, intensity, and duration), temperature, carbon dioxide concentration, humidity, wind, soil moisture, soil aeration, nutrient levels, and soil texture. This paper presents a review of the work relating plant injury to specific air pollutants as conditioned by several environmental conditions supported by research on the interactions of ozone with these environmental conditions.     

Eye Irritation as an Effect of Photochemical Air Pollution

One of the most annoying aspects of photochemical air pollution, particularly in the Southern California Air Basin, has been eye irritation. The most aggravating combination of driving in heavy traffic in Los Angeles, suffering from tearing and burning of the eyes together with very limited visibility, was a strong motivation for the public to demand that effective control actions be taken.     

Residential Indoor,Outdoor, and Workplace Concentrations of Carbonyl Compounds: Relationships with Personal Exposure Concentrations and Correlation with Sources

Abstract

Personal 48-hr exposures of 15 randomly selected participants as well as microenvironment concentrations in each participant’s residence and workplace were measured for 16 carbonyl compounds during summer–fall 1997 as a part of the Air Pollution Exposure Distributions within Adult Urban Populations in Europe (EXPOLIS) study in Helsinki, Finland. When formaldehyde and acetaldehyde were excluded, geometric mean ambient air concentrations outside each participant’s residence were less than 1 ppb for all target compounds. Geometric mean residential indoor concentrations of carbonyls were systematically higher than geometric mean personal exposures and indoor workplace concentrations. Additionally, residential indoor/outdoor ratios indicated substantial indoor sources for most target compounds. Carbonyls in residential indoor air correlated significantly, suggesting similar mechanisms of entry into indoor environments. Overall, this study demonstrated the important role of non-traffic-related emissions in the personal exposures of participants in Helsinki and that comprehensive apportionment of population risk to air toxics should include exposure concentrations derived from product emissions and chemical formation in indoor air.     

a critical review of the Effect of Air Pollution Control Regulations on Land use Planning

A study of the potential effectiveness of several strategies for reducing pollutant emissions from aircraft at a busy metropolitan airport has been carried out. This work is based on a model of emission-producing activities at the Hartsfield Atlanta International Airport and emissions from additional sources in the region surrounding the airport. A steady-state Gaussian plume dispersion model, developed previously,^1-4 was used to determine pollutant concentrations at selected receptor sites. The model of the Atlanta airport was assembled to evaluate the results of a field test of one of the strategies (engine shutdown during taxiing) performed there in late 1973. The results of that field test are reported elsewhere.^5,6 A full discussion of the interpretation of the comparison between modeled and monitored pollutant concentrations during the field test and the examination of alternative strategies noted, here are contained in the final report of this project.⁷     

Note on a Method to Estimate Missing Air Pollution Data

An iterative regression procedure is presented to estimate missing air pollution measurements when the data are measured at two or more sampling stations in the same vicinity. The procedure utilizes the measurements taken at other stations, on neighboring days, and of other pollutants.

The procedure is applied to a set of Philadelphia pollution data with from five to seventeen per cent of the observations missing. The method is tested by comparing the known observed pollutant values, with their estimates given by the procedure. Correlations between the observations and their estimates are uniformly high, ranging from 0.87 to 0.91. These correlations compare favorably with those estimates given by a simple linear interpolation. The magnitude of the correlations suggests that estimates given by this iterative regression procedure may be used where missing observations pccur without fear of undesirable effects on subsequent work. Therefore, this procedure may be a valuable tool in handling the problem of missing observations in air pollution data.     

State and Community Reactions to the Federal Air Pollution Program

The Federal Air Pollution Program is growing rapidly. Its activities are affecting state and local programs both directly and indirectly. Some of these activities are discussed and suggestions are made for developing closer cooperation in the areas of program grants, motor vehicle emission control, Federal abatement procedures, and technical assistance.     

Effect of the Pittsburgh Air Pollution Episode upon Pulmonary Function in School Children

Due to increasing atmospheric concentrations of participates, five of Allegheny County’s seven monitoring areas were placed on first stage air pollution alert by November 18,1975. The Liberty Borough area reached second stage alert, and then emergency stage the morning of November 19. An investigation was mounted to determine whether these emergency levels of par-ticulates had an effect upon the pulmonary function of school children sufficiently severe that it would require several days for pulmonary function to return to normal. Beginning November 20 in two schools and November 21 in four additional schools, the three-quarter second forced expiratory volume (FEV.75) and the forced vital capacity (FVC) of approximately 270 parochial school children in fourth, fifth, and sixth grades were tested daily through November 26. Two schools, approximately 80 children, were in control areas; the remaining children were exposed to high or very high levels of particulate air pollution with significant levels of sulfur oxides. If a severe effect of pollution on pulmonary function occurred, one would expect daily measurements to tend upward in children in the four schools in polluted areas and to remain more or less steady in the two control areas. Analyses of the data yielded no indications of such an effect of air pollution upon the lung function of the school children studied. Pulmonary function values declined very slightly in all six schools over the study period. Unexplained variability over a weekend was observed.