Environmental Factor, June 2011, National Institute of Environmental Health Sciences
NIEHS leaders set the tone at Health Affairs briefing
By Eddy Ball
"Efforts to protect health by stimulating health behaviors and improving environmental conditions represent the best and perhaps only strategy for slowing the growth of disease prevalence," Dentzer maintained in her opening remarks. "[Otherwise] the direct and indirect cost of [chronic disease] could easily overwhelm any other efforts to bend the cost curve of health care." (Photo courtesy of Health Affairs)
Birnbaum's introduction to the wide range of factors that constitute the environment set the tone for overview panel presentations and introduced themes that the daylong program of speakers would explore in their talks. (Photo courtesy of Health Affairs)
"The environment plays a major role in reprogramming the epigenome," Olden explained, seated with Morello-Frosch. "We believe there will be neighborhood-specific epigenetic signatures and possibly disease-specific epigenetic signatures." (Photo courtesy of Health Affairs)
"We cannot just regulate one chemical at a time," Morello-Frosch insisted, as she called for regulatory reform, a better understanding of cumulative impacts, and environmental parity. "Place matters. Our neighborhoods matter." (Photo courtesy of Health Affairs)
A diverse audience engaged the speakers, following the panel presentation. (Photo courtesy of Health Affairs)
NIEHS/NTP Director Linda Birnbaum, Ph.D., and Director Emeritus Ken Olden, Ph.D., led off an impressive list of speakers at a briefing May 4 in Washington, D.C. The groundbreaking event, hosted by the journal Health Affairs made possible by a grant from the Kresge Foundation (see related story (http://www.niehs.nih.gov/news/newsletter/2011/june/science-health/index.cfm)), launched the first thematic issue devoted exclusively to environmental health during the publication's 30-year history.
Moderated by Editor-in-Chief Susan Dentzer, thewas designed to educate Health Affairs readers and supporters about an area of health that Dentzer described as long-neglected, underappreciated, and incompletely understood by many people. "There's plenty that we already know," she told the audience, "but there's a lot more to know, as this issue makes clear." Dentzer pointed to estimates that the environment is involved in as much as 85 percent of disease at a cost of nearly $77 billion per year, to underscore the magnitude of the public health challenge ahead.
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Getting basic about the challenges of environmental health
Following her introductory remarks and comments from David Fukuzawa, director of The Kresge Foundation's Health Program(http://www.kresge.org/index.php/what/health_program/) , Dentzer turned to the overview panel, featuring Birnbaum, Olden, and Rachel Morrello-Frosh, Ph.D. (http://ecnr.berkeley.edu/facPage/dispFP.php?I=1554) The keynote speakers introduced important concepts in environmental health and proposed changes in policy to better safeguard the public from environmental factors that cause disease, such as reforming the Toxic Substances Control Act and striving to achieve environmental justice for all.
As the first panelist to speak, Birnbaum opened her presentation by describing the broad and complex range of factors that constitute the environment and introduced an important conceptual shift now driving health research through the paradigm of "many genes, many diseases, many exposures." Describing factors such as industrial chemicals, diet, drugs, the microbiome, psychosocial stress, and climate change, as well as their interactions and their effects on gene expression, she argued, "We've got to move beyond looking at one exposure at a time and think cumulatively."
"Chronic diseases in general have extremely complex etiologies and we need to remember that," Birnbaum continued. She also discussed the concept of windows of susceptibility and why timing makes a major difference in the effects of exposures.
Epigenetic changes that lead to disease
Olden followed Birnbaum with his talk on epigenetic changes that impose another layer of control superimposed on the genetic code. "Genetics is not the only risk factor," Olden said. "Enough emphasis has not been placed on identifying the risk factors in the other areas."
As Olden explained, "The epigenome is all the chemical tags that are added to chromatin or to histones, creating a physical structure that influences translation of genes." He compared the epigenome to the punch cards once used in computer programming, and to the role of a choreographer of a ballet troupe who decides which of the many routines in its repertoire is performed at a given venue. Olden predicted that understanding the collaboration of the genome and epigenome will be the central challenge in medical research over the next fifteen years.
The quest for environmental justice
Toward the end of his talk, Olden made a statement about the epigenetic effects of social exposures that served as a transition to the final speaker of the day, toxicologist and environmental justice advocate Morello-Frosch, who outlined the role of psychosocial stress in amplifying the effects of other exposures to trigger disease.
"[The] cumulative impacts [approach] really talks about a triple jeopardy," Morello-Frosch said, "of the ways in which social inequalities create health disparities through environmental exposures and social stressors .... We know enough now to start screening and to take precautionary action to reduce exposures and to ameliorate some of these social factors that are definitely fixable."