Kresge Center for Environmental HealthDouglas Dockery, Ph.D. Project DescriptionThe Kresge Center for Environmental Health fosters active collaborations among three Research Cores: 1) Metals, 2) Urban and Occupational Particles, and 3) Organic Pollutants. The work of the Research Cores is greatly enhanced by three Facility Cores: 1) Biological Analyses, 2) Exposures and Environmental Analyses, and 3) Environmental Statistics. Finally, the investigators' ability to make their research and knowledge available to the public is greatly enhanced by the Community Outreach and Education Program (COEP). Other Center activities, such as pilot projects, new investigators, and program enrichment are catalytic mechanisms to achieve integration, interaction, productive, and innovative science. The objectives of this Core Center are to generate new knowledge relating to the physiology, pharmacology, pathology, cell biology, molecular biology, genetics, and epidemiology of environmental disease, and to apply this knowledge to new modalities of prevention, diagnosis, and therapy. The investigators achieve these objectives through a variety of approaches, which range from studies of molecules and cells to those of whole animals and human populations. Through the organizational structure and financial support provided by the NIEHS Center Grant, the investigators' increase the impact of their research and teaching in environmental health. The Harvard NIEHS Center for Environmental Health continues to be a major focal point for environmental research and training in Boston. Project HighlightsHealth Effects of Ambient Particulate Matter (PM)Community-based particulate air pollution epidemiological analyses focus on understanding the pathways of the observed associations between particulate air pollution and acute mortality and morbidity and on identifying the susceptible portions of the population. An adjacent objective is to characterize the mechanisms responsible for these health effects. Pooled analyses from multiple cities continue to provide new insights. Particles were associated with admissions for heart failure (Wellenius et al 2006), respiratory disease (Medina-Ramon et al 2006), and heart disease (Barnett et al 2006). Case-crossover methodology was used to examine individual modifiers of the effect of particles on mortality (Zeka et al 2006). The association between PM2.5 and both all-cause and specific-cause mortality using over 1.3 million deaths in 27 US communities between 1997 and 2002 was examined (Franklin et al 2006). A two-stage approach was used. First, the association between PM2.5 and mortality in each community was quantified using a case-crossover design. Second, meta-analysis was used to estimate a summary effect over all 27 communities. Effect modification of age and gender was examined using interaction terms in the case-crossover model, while effect modification of community-specific characteristics including geographic location, annual PM2.5 concentration above 15 mug/m3 and central air conditioning prevalence was examined using meta-regression. A 1.21% (95% CI 0.29, 2.14%) increase in all-cause mortality, a 1.78% (95% CI 0.20, 3.36%) increase in respiratory related mortality and a 1.03% (95% CI 0.02, 2.04%) increase in stroke related mortality with a 10 mug/m3 increase in previous day’s PM2.5 were observed. The magnitude of these associations is more than triple that recently reported for PM10, suggesting that combustion and traffic related particles are more toxic than larger sized particles. Effect modification occurred in all-cause and specific-cause deaths with greater effects in subjects >/=75 years of age. There was suggestive evidence that women may be more susceptible to PM2.5 effects than men. Increased prevalence of central air conditioning was associated with a decreased effect of PM2.5. These findings suggest that PM2.5 may pose a public health risk even at or below current ambient levels. Medina-Ramon et al (2006) conducted a case-crossover study in 36 US cities to evaluate the effect of ozone and particulate matter (PM10) on respiratory hospital admissions. The study confirmed that exposure to ozone and PM10 is associated with respiratory hospital admissions, and provided evidence that the effect of air pollution is modified by certain city characteristics, such as the likelihood of central air conditioning and the variability of summer temperatures. Zeka et al (2006) examined individual modifiers in a case-crossover study of 20 US cities. PM10 mortality was influenced by gender and age and the level of education was inversely related to the risk of PM10 associated mortality. A diagnosis of diabetes modified the effect of PM10 for respiratory and stroke mortality. These findings suggest that more attention must be paid to population characteristics to better understand susceptibility. Dubowsky SD, Suh H, Schwartz J, Coull BA, and Gold DR. Diabetes, obesity, and hypertension may enhance associations between air pollution and markers of systemic inflammation. Environ Health Perspect. 2006; 114(7):992-8. Organic Pollutants, Children’s Health, and Reproductive HealthEnvironmental PCB and Phthalate Reproductive Health Study Organophosphate Exposure and Semen Quality Study Organochlorines and Reproductive Health among Women Hauser R, Meeker JD, Singh NP, Silva MJ, Ryan L, Duty S, Calafat AM. DNA damage in human sperm is related to urinary levels of phthalate monoester and oxidative metabolites. Human Reprod. 2007; 22:688-95. |
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