Extramural Research
Research Centers
Grantee Research Project Results
Petros Koutrakis, Director
Harvard University, Boston, MA
EPA Grant Number: R827353
2003
Progress Reports
Center
sub-projects
The objective of the EPA/Harvard PM Center is to address key scientific issues regarding the health effects of ambient particles. To address these aims, our Center focuses upon three research themes: (I) Expo-sure, (II) Susceptibility, and (III) Biological Mechanisms/Dosimetry. Each theme encompasses a series of highly integrated and interdisciplinary research projects. Theme I has investigated human exposures to parti-cles and gaseous co-pollutants in order to differentiate the health effects of particles from outdoor and indoor sources. Considerable research has been conducted at the Harvard PM Center validating the use of ambient PM2.5 concentrations as personal exposure surrogates in epidemiological studies and examining the role of ventilation as a factor influencing personal-ambient PM associations. These results have led researchers to investigate whether ventilation may explain some of the heterogeneity in hospital admission rates for individuals with CVD and COPD. The results of this analysis provided initial evidence that home characteristics influenced the impact of ambient PM on human health. Due, in part, to our efforts new research proposals both within and outside of Harvard are designed to account for variability in ventilation across exposed populations. Theme II has focused on identifying individuals who are sensitive to the effects of PM air pollution assess, whether these individuals are “harvested” by air pollution episodes, and measures the effect of chronic air pollution exposure on the development of chronic diseases. Our recent acute epidemiological studies have also shed light on identifying susceptible populations such as individuals with cardiopulmonary disease. Recently, these findings have also indicated that diabetics constitute an additional high-risk population. These results are important for designing future acute and chronic epidemiological studies. Theme III has targeted the identification of par ticulate characteristics and gaseous air pollutants that trigger adverse health effects and define the biological mechanisms that may lead to fatal outcomes. Results from our controlled exposure studies have provided new information concerning the toxicity of ambient as well as specific components of ambient particulate matter including re-suspended road dust. These results have highlighted the potential health risks for individuals living or working near busy roads. Another important finding to emerge from our Theme III research comes from inhalation studies using concentrated ambient particles along with carbon monoxide in a rat model. No synergism was found between CAPs and carbon monoxide in incidence of arrhythmias, providing initial evidence concerning the potential for interaction effects between particles and its gaseous co-pollutants.
The interdisciplinary nature of the Harvard PM Center has enabled us
to integrate findings from a variety of studies as they emerge and, combined
with structured methods to evaluate research needs and priorities, allowing
the Center to remain flexible and at the forefront of the health effects
research on particles. In turn, the scientific information generated by
Harvard and other Centers has served as a basis for the EPA to establish
new public health policies and to redefine particle research needs.