ESE student’s practicum project aims to improve human health assessment

October 31, 2012
How do plasticizers, such as diethylhexyl phthalate (DEHP), cause cancer?
Mary Kushman, MD, a Master of Public Health candidate in environmental sciences and engineering at UNC Gillings School of Global Public Health, asked the question in her role as a fellow with the U.S. Environmental Protection Agency’s (EPA) Human Health Risk Assessment (HHRA) research program.
The question is critical when interpreting the large and complex database of more than 3,000 peer-reviewed publications on the topic.
Kushman’s public health practicum fellowship, supported by the Oak Ridge Institute for Science and Education, enables her to work with HHRA in Washington, D.C., and Research Triangle Park, N.C., from June to December 2012.
The HHRA program evaluates evidence, identifies potential health hazards and establishes quantitative values indicative of potential risks from exposures. In recent years, the National Research Council and other stakeholders have emphasized the need for improved evidence capture and reporting for risk assessments, using systematic and transparent literature review.
Given the extensive literature on DEHP, Kushman saw potential to turn an otherwise formidable task into an opportunity to improve the literature review process, which is an essential step in conducting human health assessments of environmental chemicals.
Click for larger image

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In developing her strategy, Kushman drew on expertise from HHRA staff engaged in human health risk assessments, EPA’s Health and Environmental Research Online (HERO) database librarians, and her adviser, Ivan Rusyn, MD, PhD, professor of environmental sciences and engineering at UNC’s public health school.

Kushman sought to pilot innovative solutions for capturing and reporting evidence in a stepwise, clear, succinct process. Her project involved defining how to search the literature, collect and screen evidence according to tiered criteria, and develop graphic aids such that information can be presented more clearly. She captured and structured primary literature in the HERO database so that it could be retrieved in a more organized way. The result was clear documentation of literature search strategies and analysis methodologies, as well as insight into how specific evidence supports conclusions about DEHP’s mechanism of action.
A mechanism of action is a biochemical interaction through which a substance produces a given effect.
Kushman’s approach effectively manages large databases, improves appraisal and synthesis of information, and enables researchers to analyze DEHP’s mechanism of action across studies.
According to Rusyn, Kushman’s approach could be useful for other human health assessment activities, enhancing the quality of the literature review process while reducing the inherent burden of the process.
“This project demonstrates the success of applying a systematic review solution to a well-formulated question of critical importance to public health decision-making,” added Kate Guyton, PhD, acting director of EPA’s HHRA program.


UNC Gillings School of Global Public Health contact: David Pesci, director of communications.