Mass and Elemental Composition of Fine and Coarse Particles in Six U.S. Cities

Inhalable particulate matter (IP) samples have been collected in six U.S. cities in conjunction with an air pollution health study. The IP were collected using dichotomous virtual impactors in two size ranges: fine particles (FP) having aerodynamic diameter (d_a) <2.5 μm, and coarse particles (CP) with 2.5 μm < da < 15 μm. The mass measurements were determined by beta-gauge attenuation. The elemental composition of the FP and CP were determined by X-ray fluorescence. The means and distributions for FP and CP and selected elemental data highlight the similarities and differences that exist among these cities in the health study. Examining the temporal variations gives additional information on the meteorology and sources influencing the FP and CP fractions of Inhalable particle mass.

Differences in the concentration (and ratios) of selected elements have indicated the varying presence of crustal, steel industry, automotive, oceanic and fuel combustion sources in these cities. The noted variation in the concentrations and character of ambient aerosols in these cities are pertinent to interpreting differences in population exposures.     

Overview of the U.S. Environmental Protection Agency's Hazardous Air Pollutant Early Reduction Program.

Under provision of the Clean Air Act Amendments of 1990 Title III, the EPA has proposed a regulation (Early Reduction Program) to allow a six-year compliance extension from Maximum Achievable Control Technology (MACT) standards for sources that voluntarily reduce emissions of Hazardous Air Pollutants (HAPs) by 90 percent or more (95 percent or more for particulates) from a base year of 1987 or later. The emission reduction must be made before the applicable MACT standard is proposed for the source category or be subject to an enforceable commitment to achieve the reduction by January 1, 1994 for sources subject to MACT standards prior to 1994. The primary purpose of this program is to encourage reduction of HAPs emissions sooner than otherwise required. Industry would be allowed additional time in evaluating emission reduction options and developing more cost-effective compliance strategies, although, under strict guidelines to ensure actual, significant and verifiable emission reductions occur.     

Air Pollution and Hospital Admissions for Diseases of the Circulatory System in Three U.S. Metropolitan Areas

ABSTRACT

Generalized additive models were used to analyze the time series of daily hospital admissions for cardiovascular and cerebrovascular diseases over the period of 19871995 in three major metropolitan areas—Cook County, IL; Los Angeles County, CA; and Maricopa County, AZ— in the United States. In Cook and Maricopa Counties, admissions information was only available for the elderly (ages 65 and over), while in Los Angeles County, admissions information was available for all ages. In Cook County, daily monitoring information was available on PM₁₀, CO, SO₂, NO₂, and O₃. In Los Angeles and Maricopa Counties, monitoring information was available daily on the gases, and information on PM₁₀ was available every sixth day. In Los Angeles County, information on PM₂₅ was also available every sixth day. In Cook and Los Angeles Counties, associations were found between each pollutant, with the exception of O₃, and admissions for cardiovascular disease, with the gases showing the strongest associations. In two-pollutant models with PM and one of the gases, the effect of the gases remained stable, while the effect of PM became unstable and insignificant. In Maricopa County, the gases, with the exception of O₃, were weakly associated with hospital admissions for cardiovascular disease, while PM was not. In two-pollutant models with two of CO, SO₂, and NO₂, the pattern of results is heterogeneous in the three counties. In all three counties, only weak evidence of any association between air pollution and cere-brovascular admissions was found.     

Infant Mortality and Air Pollution: A Comprehensive Analysis of U.S. Data for 1990

ABSTRACT

This paper uses U.S. linked birth and death records to explore associations between infant mortality and environmental factors, based on spatial relationships. The analysis considers a range of infant mortality end points, regression models, and environmental and socioeconomic variables. The basic analysis involves logistic regression modeling of individuals; the cohort comprises all infants born in the United States in 1990 for whom the required data are available from the matched birth and death records. These individual data include sex, race, month of birth, and birth weight of the infant, and personal data on the mother, including age, adequacy of prenatal care, and smoking and education in most instances. Ecological variables from Census and other sources are matched on the county of usual residence and include ambient air quality, elevation above sea level, climate, number of physicians per capita, median income, racial and ethnic distribution, unemployment, and population density. The air quality variables considered were 1990 annual averages of PM₁₀, CO, SO₂, SO₄ ^2-, and “non-sulfate PM₁₀” (NSPM₁₀—obtained by subtracting the estimated SO₄ ^2-mass from PM₁₀). Because all variables were not available for all counties (especially maternal smoking), it was necessary to consider various subsets of the total cohort.

We examined all infant deaths and deaths by age (neonatal and postneonatal), by birth weight (normal and low [<2500 g]), and by specific causes within these categories. Special attention was given to sudden infant death syndrome (SIDS). For comparable modeling assumptions, the results for PM₁₀ agreed with previously published estimates; however, the associations with PM₁₀ were not specific to probable exposures or causes of death and were not robust to changes in the model and/or the locations considered. Significant negative mortality associations were found for SO₄ ^2-. There was no indication of a role for outdoor PM_2.5, but possible contributions from indoor air pollution sources cannot be ruled out, given higher SIDS rates in winter, in the north and west, and outside of large cities.     

I. Ragweed Pollen as Air Pollution

By their land use practices the agricultural and construction industries are unwittingly causing an increase in atmospheric pollution by aeroallergens such as ragweed pollen. This public health problem is discussed in the following four papers by an interdisciplinary team. Possible remedies are described.     

Source Apportionment: Findings from the U.S. Supersites Program

Abstract

Receptor models are used to identify and quantify source contributions to particulate matter and volatile organic compounds based on measurements of many chemical components at receptor sites. These components are selected based on their consistent appearance in some source types and their absence in others. UNMIX, positive matrix factorization (PMF), and effective variance are different solutions to the chemical mass balance (CMB) receptor model equations and are implemented on available software. In their more general form, the CMB equations allow spatial, temporal, transport, and particle size profiles to be combined with chemical source profiles for improved source resolution. Although UNMIX and PMF do not use source profiles explicitly as input data, they still require measured profiles to justify their derived source factors. The U.S. Supersites Program provided advanced datasets to apply these CMB solutions in different urban areas. Still lacking are better characterization of source emissions, new methods to estimate profile changes between source and receptor, and systematic sensitivity tests of deviations from receptor model assumptions.     

Source apportionment: findings from the U.S. Supersites Program

Receptor models are used to identify and quantify source contributions to particulate matter and volatile organic compounds based on measurements of many chemical components at receptor sites. These components are selected based on their consistent appearance in some source types and their absence in others. UNMIX, positive matrix factorization (PMF), and effective variance are different solutions to the chemical mass balance (CMB) receptor model equations and are implemented on available software. In their more general form, the CMB equations allow spatial, temporal, transport, and particle size profiles to be combined with chemical source profiles for improved source resolution. Although UNMIX and PMF do not use source profiles explicitly as input data, they still require measured profiles to justify their derived source factors. The U.S. Supersites Program provided advanced datasets to apply these CMB solutions in different urban areas. Still lacking are better characterization of source emissions, new methods to estimate profile changes between source and receptor, and systematic sensitivity tests of deviations from receptor model assumptions.     

Long-Term Wind Speed Variations for Three Midwestern U.S. Cities

Abstract

Long-term wind speed variations were investigated for three midwestern cities including Indianapolis, IN; Cincinnati, OH; and Little Rock, AR in the continental United States. These cities were chosen because their topography is relatively ?at and unaffected by large mountain ranges or other topographical features, they represent important regional economic centers, and they have all undergone major air quality management efforts over the past 35 yr to attempt to meet the National Ambient Air Quality Standards. The hourly data were obtained from the National Climatic Data Center from 1943 to 2008 for Indianapolis and Little Rock and from 1948 to 2008 for Cincinnati. The analysis included calculating the frequency of calms and wind speeds over five different bins for the respective cities. The results indicate a significant increase in the frequency of calms (statistical significance >99.999%) and a decrease in the overall frequency of other wind speeds for all three cities. Increasing trend in calms is more predominant during the ozone season (April through October). The results from regression analysis, significance testing, and spatial correlation analysis support the argument that a common “midwestern” large-scale atmospheric forcing is in?uencing surface wind speed in this area. It was found that for all three cities the Pacific North American (PNA) teleconnection pattern has the highest relative association with the trends in wind speed. The results support large-scale continental effects (like teleconnections) as a hypothesis to be examined more closely along with already established evidence of the influence of the Pacific and Atlantic teleconnection anomalies. Reduced wind speed may have implications on air quality management efforts in the region. Increases in the frequency of calms would affect ozone distribution patterns and may suggest a need to make changes to their ozone mitigation strategy. Weaker winds would ventilate pollutants from these areas less effectively, which could be problematic from a human health point of view, particularly for asthmatics.     

Air Quality Impact of Aircraft at Ten U.S. Air Force Bases

Data on visits to New York City metropolitan area hospital emergency rooms for asthmatic attacks were analyzed to identify asthma “events”: days when the number of such visits was unusually high. In the fall season such days tended to occur simultaneously at all hospitals of the study, and thus can be plausibly associated with some environmental agent acting simultaneously throughout the city. Data on sulfur dioxide and particulate concentrations from the 40-station New York City Aerometric Network were used as pollution measures, and a search for a relationship between asthma “events” and air pollution levels on the same day and on the preceding day was made using standard statistical techniques. No relationship was found.     

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.     

Performance Budgeting for the Public Health Service Air Pollution Program

The Lurgi-MB-Filler collects dust from industrial gases by mechanical means in a dry state. It works in continuous operation at temperatures up to 660°F with high dust collecting efficiencies and a low draft loss. The gas to be cleaned passes through a filter bed consisting of abrasion resisting material such as gravel, etc. The captured dust is removed from the filter bed by a patented vibrating system which shakes the spring supported filter bed containers. Simple design and automatic operation ensure low investment and operating costs and give an economic superiority in the fields of cleaning waste air from clinker coolers, conveyors, crushers, pulverizing mills, driers, and preparation plants.     

Inter-Urban Comparison of Ambient Volatile Organic Compound Concentrations in U.S. Cities

Airborne particulate matter from three ferrous foundries was sampled in granulometric fractions and analyzed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDXA), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) to determine morphology and qualitative bulk and surface chemical compositions. Cluster and principal components analyses (PCA) were used as an aid for interpretation of results. A clear pattern of composition as a function of size emerges; in particular, trace metals accumulate in fine particles and volatile species on the surface of these. Chemical composition changes are also related to daily schedules where applicable: trace metals appear during pouring operations, silicon is generated during mold making and unmolding. Cluster and PCA greatly ease examination of data and offer pictorial representations of results; in particular, the chemical composition versus particle size relationship is very neatly illustrated by PCA graphs.     

Radiological Program of the Los Angeles County Air Pollution Control District

Abstract

One technology Geld tested under the SITE demonstration program was stabilization-solidification. The HAZCON process was one of those tested. It treats hazardous wastes, consisting of both inorganic and organic contaminants, by mixing it with portland cement, water and a proprietary additive called Chloranan in a modified cement mixer to produce a concrete mass. In evaluating the technology during the demonstration, two major criteria were investigated by using existing laboratory tests. These criteria were mobility of the contaminants before and after treatment and the long-term effect on mobility, and durability of the solidified masses. The former criteria was evaluated using various leaching tests, primarily the Toxicity Characteristic Leaching Procedure (TCLP) and permeability. The durability criteria was determined from weathering tests, wet-dry and freezethaw, unconfined compressive strength, microstructural analyses and sampling the prepared blocks from the demonstration twice at 9-month intervals. This paper describes the results of the field sampling performed 9 and 18 months after the initial field demonstration and relates it to the results obtained during the demonstration.

According to the data, little or no change in the chemical and physical properties of the blocks occurred. The technology is capable of immobilizing heavy metals. The organics were not immobilized and the treated material appears quite durable.     

Some Basic Consideration in the Design of an Air Pollution Monitoring System

Quantified air quality and meteorological information provided by an air pollution monitoring system must be geared to the legally prescribed functions of the control agency. The network must be treated as a vital component of the total integrated data system that supports agency activities in air resources management and control. It should be closely interphased with data systems for emission inventory, registration and permits, violations and complaints, fuel use, emission reduction plans, land use, demographic projections, and urban planning. Compatibility with neighboring and statewide or regionwide data systems is essential for coordination of effort, especially under episode conditions.

The network should be planned on three levels, static, semi-automatic, and fully automatic, to provide monthly, daily, and up-to-the-minute measurements, respectively. Optimization of network specifications requires a three-way balance of hardware, control objectives, and agency resources (capital facilities, manpower, funding, etc.), of which the first two are realistically governed by the third.

A monitoring network could serve a wide range of functions, and there are pressures and temptations to cater to all possible users. A number of functions are listed; an order of priority should be determined. Experience shows that far more data tend to be generated than can be analyzed, assimilated, and utilized. Rapid data acquisition and on-line processing capabilities of present-day automatic networks could, without effective planning, result in mountainous backlogs of unassimilated information.

A systems engineering approach to planning will ascertain that preliminary requirements are critically scrutinized, and only genuine requirements that meet the test of constraints (natural environment, economic, legal, social, political constraints, and manpower resources) will be translated into performance specifications. By means of this approach, design characteristics that are extraneous or peripheral to the principal network functions can be identified as low priority luxuries, whereas seemingly expensive items may be justified on the basis of data reliability or long-range savings in operation and maintenance requirements.