Initiative for Environmental-Health Disparities and Medicine
About the Director
The research program of Darryl B. Hood is in the area of Environmental Health and Toxicology with a particular interest in the effects of exposure to environmental toxicants during critical periods of CNS development and the subsequent effects on behavioral learning in the offspring. The specific compounds of interest are polycyclic aromatic hydrocarbons (PAHs). The environmental contaminants of immediate concern to minority communities are released as emission by-products from industrial environmental polluters. Dr. Hood’s laboratory has been investigating and characterizing the health effects of polycyclic aromatic hydrocarbon exposure using various exposure regimens for over a decade. The long-term goal is to determine the mechanistic connection between environmental insults to experience-dependent neural activity and alterations in gene expression during the postnatal period when synapses are forming for the first time (PND7-14). The recent finding by a group at Vanderbilt [Morrow et al., (2008)] has illuminated the fact that deletions of certain genes that are regulated by neuronal activity or that certain regions of these genes are potentially involved in regulation of gene expression in environmental exposure-induced disease. This work has served to spotlight Dr. Hood’s studies where he is testing hypotheses of prenatal toxicant-induced insult to activity-dependent gene expression being causative for behavioral deficits in the neuropathology of at least a subset of environmental exposure-induced behavioral learning disorders.
The studies conducted in his laboratory are appropriately focused on the developing brain realizing that we know very little about the details of how genes and experience interact within the developing central nervous system to create something as complex as a phenotype referred to as behavioral learning. Dr. Hood has anticipated a paradigm shift in the field and realizes that this will be extremely relevant to the future of environmental medicine and toxicology research as the focus on epigenomics (changes in gene expression due to alterations in protein-DNA interactions rather than DNA sequence) takes center stage. It is likely that this will be a critical focus in the field as advances in understanding how experience alters the genome come to fruition.
The impact of ongoing research in Dr. Hood’s laboratory utilizing animal models has contributed to an understanding of the etiology of a number of environmental-exposure influenced disorders such as autism spectrum disorder, male reproductive dysfunction, low birth weight and cognitive deficits in infants and children in communities located near landfills, near environmental polluters, and toxic waste sites. Thus far, studies from Dr. Hood’s laboratory have provided mechanistic data that support associations between specific environmental exposures and central nervous system and reproductive dysfunction. From a cumulative risk-assessment perspective, data from Dr. Hood’s laboratory has contributed to the database that addresses why low income and medically underserved populations that work, reside, attend school, and play in environmentally contaminated neighborhoods have disproportionate adverse cognitive and reproductive health outcomes. Consistent with the Healthy People 2010 initiative, work from Dr. Hood’s laboratory has contributed to the formulation of prevention and intervention strategies and public policy changes that have resulted in the reassessment by the EPA of permissible ambient level emission of PAH’s from industrial emitters. These public policy changes serve to decrease the adverse health effects associated with environmental exposures.
