Ron Wyzga

The Aerosol Research and Inhalation Epidemiology Study (ARIES): PM2.5 mass and aerosol component concentrations and sampler intercomparisons.

ABSTRACT The Aerosol Research and Inhalation Epidemiology Study (ARIES) was designed to provide high-quality measurements of PM25, its components, and co-varying pollutants for an air pollution epidemiology study in Atlanta, GA. Air pollution epidemiology studies have typically relied on available data on particle mass often collected using filter-based methods. Filter-based PM2.5 sampling is susceptible to both positive and negative errors in the measurement of aerosol mass and particle-phase component concentrations in the undisturbed atmosphere. These biases are introduced by collection of gas-phase aerosol components on the filter media or by volatilization of particle phase components from collected particles. As part of the ARIES, we collected daily 24-hr PM2.5 mass and speciation samples and continuous PM2.5 data at a mixed residential-light industrial site in Atlanta. These data facilitate analysis of the effects of a wide variety of factors on sampler performance. We assess the relative importance of PM2.5 components and consider associations and potential mechanistic linkages of PM2.5 mass concentrations with several PM2.5 components. For the 12 months of validated data collected to date (August 1, 1998-July 31, 1999), the monthly average Federal Reference Method (FRM) PM2 5 mass always exceeded the proposed annual average standard (12-month average = 20.3 ± 9.5 ug/m3). The particulate SO4 2- fraction (as (NH4)2SO4) was largest in the summer and exceeded 50% of the FRM mass. The contribution of (NH4)2SO4 to FRM PM2.5 mass dropped to less than 30% in winter. Particu-late NO3 - collected on a denuded nylon filter averaged 1.1 ± 0.9 ug/m3. Particle-phase organic compounds (as organic carbon × 1.4) measured on a denuded quartz filter sampler averaged 6.4 ± 3.1 ug/m3 (32% of FRM PM2 5 mass) with less seasonal variability than SO4 2-.

A Two-Time-Period Comparison of the Effects of Ambient Air Pollution on Outpatient Visits for Acute Respiratory Illnesses

Abstract Concentrations of numerous ambient air pollutants have declined in recent years across the United States. Although it can be expected that reductions in air pollutants are associated with reductions in health effects, it is unclear whether this is actually the case. The purpose of this analysis was to compare the levels of and relationships between air pollutants and acute respiratory outpatient visits for two consecutive time periods totaling 53 mo. Air pollution data were collected at a centrally located monitor in Atlanta, GA, and include 24-hr averages of particulate matter (PM) less than 2.5 μm in aerodynamic diameter (PM2.5) and its components; coarse PM (PM10-2.5); PM less than 10 μm in aerodynamic diameter (PM10); oxygenated volatile organic compounds (OVOCs); 8-hr maximum ozone (O3); and 1-hr maximum nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2). In addition, several metals and fractions of elemental carbon (EC) and organic carbon (OC) were investigated. Daily outpatient visit data were obtained from the electronic data warehouse of the Atlanta-based region of a nonprofit managed care organization. Poisson general linear modeling determined associations between daily levels of acute visits for four diagnosis groups (adult and child asthma, upper and lower respiratory infection) and air pollution measurements. Overall declining trends were observed in air pollutants and acute visits over the study period. Childhood asthma had the greatest number of significant associations with air pollutants, namely zinc and EC. The significant lag time between pollutant measurement and visit occurrence changed from 3-5 days in the first time period to 6-8 days in the later time period, but there was general consistency in several childhood asthma and pollutant associations over both time periods. The greatest evidence for a reduction in pollution being associated with an improvement in health response was for lower respiratory disease visits, but even in this case changes in other factors that influence health responses make it difficult to demonstrate that changes in pollutant levels influence health outcomes.

Health Assessment Aspects of Risk- and Results-Based Multipollutant Air Quality Management

Knowledge of the health impacts of air contaminants is key to both the development of risk-based multipollutant air quality management strategies and the evaluation of their success in reducing the health burden of air pollution. This chapter summarizes the present ability of health sciences researchers to produce evidence useful for informing the development of multipollutant air quality management and assessing the resulting health benefits, the advances in knowledge and research strategies that will be required to substantially advance that ability, and the progress we can reasonably expect over the next decade. The chapter deals with key elements of the risk assessment framework described in Chap. 4, especially assessing exposure, identifying causal pollutants and combinations, and determining exposure-response relationships (potency factors). It concludes that continued progress toward supporting multipollutant air quality management will occur in incremental steps as we become able to integrate increasing numbers of individual pollutants, pollutant groupings, and sources, and their corresponding health risks. Progress towards developing multipollutant air quality management strategies and accounting for their success will depend upon how well we understand the links between various pollutants and health, and how confidently we can measure pollutant-related changes in the health impacts we seek to reduce.

Childhood Asthma Acute Primary Care Visits, Traffic, and Traffic-Related Pollutants

UNLABELLED Previous studies have found associations between traffic-related air pollution and asthma exacerbation in children, where exacerbations were measured according to emergency department visits and hospital admissions. Fewer studies have been undertaken that look at asthma exacerbations in a less severe primary care setting. Therefore, the authors sought to examine the associations between childhood asthma exacerbations, measured as acute visits to a primary care setting, and vehicular-traffic measures in a population of children aged 18 and under in the metropolitan Atlanta area. Statistical tests for differences of mean monthly visits for members with traffic measures above the median compared with below the median and for the upper quartile compared with the lower quartile were conducted. We also compared the odds of having one or more visits in a month for those who lived closer to a major roadway were compared with those who lived farther (greater than 300 m) from a major roadway. Poisson general linear modeling was used to determine associations between daily levels of acute visits for childhood asthma and traffic-related pollutants (zinc, EC [elemental carbon], and PM10 and PM2.5 [particulate matter with an aerodynamic diameter of < or = 10 and < or = 2.5 microm, respectively]) for different levels of traffic and distance measures. This analysis found that both larger traffic volumes and smaller distances to the nearest major roadway were positively and significantly associated with larger numbers of childhood asthma visits, when compared with less traffic and larger distances. Our findings point to motor vehicle traffic as an important contributor to childhood asthma exacerbations. IMPLICATIONS Previous studies have found associations between traffic-related air pollution and asthma exacerbation in children. However, these studies were mainly conducted in emergency department or hospital admission settings; little is known regarding less acute health effects. This analysis of the association between vehicular traffic measures and childhood asthma in a primary care setting suggests that motor vehicle traffic is a contributor to less acute asthma episodes in children. The present analysis of traffic-related air pollutants and childhood asthma were less conclusive, likely due to methods limitations outlined in the paper. The implication is that further evidence of adverse respiratory health effects in children due to motor vehicle traffic can be found in a primary care setting and similar studies should be considered.

A Comparison of the Effects of Ambient Air Pollution on Outpatient Visits for Acute Respiratory Illnesses Over Two Time Periods

Abstracts published in EPIDEMIOLOGY have been reviewed by the organizations of EPIDEMIOLOGY. Affliate Societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of EPIDEMIOLOGY.s published in EPIDEMIOLOGY have been reviewed by the organizations of EPIDEMIOLOGY. Affliate Societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of EPIDEMIOLOGY. ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009