Research Reports

Research Report 191 describes a study by Allison Fryer and colleagues that addressed how exposure to ozone affects the immune and physiological responses in guinea pigs. In her study, Dr. Fryer focused on eosinophils, white blood cells that play an important role in inflammation, allergies, and allergic asthma, and can modify the airway response to ozone inhalation. This study tested a novel hypothesis: that allergic guinea pigs react differently to ozone than normal animals because of newly formed eosinophils that migrate from bone marrow to the lungs.

HEI Research Report 189 describes a study by Dr. Zhengmin Qian conducted in Wuhan, the capital city of Hubei province in China. Wuhan experiences temperature extremes and generally has higher air pollution levels than those seen in the United States and Europe. Dr. Qian examined whether increased exposures to air pollutants (particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) during vulnerable pregnancy periods were associated with increased rates of preterm birth, low birth weight, or intrauterine growth retardation, using both a cohort and nested case-control design.

HEI Research Report 187 was funded as part of HEI’s Accountability research program, aimed at understanding whether actions to improve air quality have resulted in improved health outcomes. Corwin M. Zigler and his colleagues used existing and newly developed statistical methods to assess whether an intervention was causally related to changes in pollutant levels or health outcomes, and applied their methods in two well-developed case studies: effects of air quality interventions to reduce PM₁₀ concentrations in nonattainment areas and the impact of installation of scrubber technologies on emissions from coal-fired power plants.

This report is Part 3 of HEI Research Report 183, Development of Statistical Methods for Multipollutant Research. It describes a study to develop and apply statistical methods to analyze the effects of multipollutant exposures on health, expanding beyond the two-pollutant approaches used in many studies to date. HEI funded three innovative studies in recent years to improve the tools for analyzing complex multipollutant exposures. In this last report from these studies, John Molitor and colleagues describe a Bayesian framework to identify spatial clusters of air pollution exposures — and other covariates such as socioeconomic status — and estimated pregnancy outcomes associated with those clusters, using a data set for Los Angeles county.