Research Reports

Dr H-Erich Wichmann and colleagues at the National Research Center for Environment and Health in Germany prospectively studied the association of daily mortality data with the number and mass concentrations of ultrafine and fine particles in Erfurt, Germany. Concentrations were measured near a road and a time-series approach was used to look at short-term changes in particle concentration and concurrent deaths due to cardiovascular and respiratory causes over a period of 3.5 years.

Dr Morton Lippmann and colleagues at the New York University School of Medicine attempted to identify and characterize components of PM and other air pollution mixtures that were associated with excess daily deaths and elderly hospital admissions in and around the area of Detroit, Michigan. Using publicly available data from 1985-1990 and 1992-1994, the investigators used statistical models to weigh the strength of one pollutant or two pollutants concurrently.

In an effort to address the uncertainties regarding the association between PM and daily mortality, and to determine the effects of other pollutants on this association, HEI funded the National Morbidity, Mortality, and Air Pollution Study (NMMAPS). Dr Jonathan Samet and his colleagues at Johns Hopkins University, in collaboration with investigators at Harvard University, conducted this time-series study in large cities across the US where levels of PM and gaseous pollutants were varied.

As part of the Health Effects Institute's air toxics research program, five independent studies were designed to advance our understanding of the roles of different metabolites in 1,3-butadiene (BD)-induced carcinogenesis and of the differences in sensitivity among species, and to develop methods for identifying and measuring biomarkers. The investigators focused on two BD metabolites (1,2-epoxy-3-butene [BDO] and 1,2,3,4-diepoxybutane [BDO₂]) that researchers had suspected may play a role in BD carcinogenesis. The studies were conducted by Dr. Rogene Henderson (Lovelace Respiratory Research Institute), Dr. Leslie Recio (CIIT), Dr. Vernon Walker (New York State Department of Health), Dr. Ian Blair (University of Pennsylvania), and Dr. James Swenberg (University of North Carolina at Chapel Hill).

Dr. Pryor and colleagues at Louisiana State University developed methods for measuring ozone reaction products in in vitro models of lung lining fluids exposed to ozone and in lung fluids from rats exposed to ozone. During the study, Dr. Mark Frampton of the University of Rochester provided Pryor with lung fluids from humans exposed to air or ozone under controlled conditions. Frampton and colleagues exposed exercising smokers and nonsmokers to filtered air or to 0.22 parts per million (ppm) ozone for four hours.

In a follow-up study to previous research, Dr. Mercer and colleagues at Duke University exposed three groups of rats continuously for six weeks to 2 or 6 ppm nitric oxide (NO) or to filtered air to learn more about the toxicity of NO so as to compare it with two other important oxidants, ozone and nitrogen dioxide (NO₂). At the end of the exposure period he used an electron microscope to measure the number of holes in the alveolar septa and to observe other structural changes, such as in the surface area and the number and type of other abnormalities in the alveolar septa.

Dr. Navidi and colleagues at the University of Southern California discussed the development of three sophisticated statistical methods that would improve the estimates of the health effects of air pollution obtained from epidemiologic studies. First, they took a standard case-crossover design and introduced a bidirectional element where control data were obtained both before and after the health event of interest.

Dr. Arey and colleagues of the University of California, Riverside, examined the genotoxic potential of two PAHs (naphthalene and phenanthrene) that are common air pollutants, and a subset of their atmospheric transformation products. The investigators evaluated the genotoxicity of these compounds using a variety of human cell lines with a range of metabolic capabilities. They examined the ability of these compounds to produce small-scale (damage to genes) and large-scale (damage to chromosomes) genetic damage.