For Betty Malloy, promoting progressive public health policy is a matter of numbers. "As a statistician, I get to participate in some projects that ask big questions in terms of getting at the health impacts of occupational and/or environmental exposures on individuals," the statistics professor says. "I feel lucky that I can contribute to some underlying body of knowledge regarding these effects."
Malloy is currently developing statistical models for two projects that examine environmental effects on health. In one study, she is working with Ellen Eisen of UC-Berkeley on a disease pattern study that examines the effects of auto plant chemicals on over 46,000 General Motors workers during a span of nearly seven decades. The study is sponsored by GM and the United Auto Workers, with Malloy's work funded by a grant from the National Cancer Institute.
By modeling the relationships between exposure to these chemicals and instances of various cancers, Malloy has demonstrated a connection between high exposure and increased relative risk of these diseases. Findings to date have been published in Occupational and Environmental Medicine, International Journal of Biostatistics and Computational Statistics and Data Analysis.
Malloy is also working with Harvard biostatistician Brent Coull on a study examining the effects of air pollution on heart rate and nitric oxide levels in the blood. Sponsored by the National Institutes of Health and the Environmental Protection Agency, the study involves 45 individuals who went on multiple field trips from a suburban environment into St. Louis. By examining information collected from breath analyses, blood samples, and heart rate variation in each participant, the team is examining associations between increased pollution exposure and increased heart rates and nitric oxide levels.
The information derived from the breath analyses and blood work has been published in the journal Biostatistics. Malloy is currently working on examining the heart rate data—which was taken over the course of the participants' excursions— and its association with pollution exposure.
"The EPA regularly reviews its air pollution standards, and studies like this are one small piece in the puzzle in terms of impact of exposure to traffic pollution," says Malloy. "In terms of regulation, we hope that these studies add to the overall understanding of how pollution impacts the health of the people."