Environmental Factor, March 2009, National Institute of Environmental Health Sciences
NIEHS Grantees Speak at Global Health Symposium
By Eddy Ball
Veteran NIEHS Grantees Peter Thorne, Ph.D., and Joseph Graziano, Ph.D., were among the global health experts giving keynote talks at the Managing Toxic Risks for Global Health symposium February 20 at Duke University. Along with five other experts, Thorne and Graziano explored the goals of clean air, pure water and safe food in preventing disease and improving environmental health at the daylong symposium.
Sponsored by the Duke Integrated Toxicology and Environmental Health Program (http://toxicology.geneimprint.com/) , the NIEHS-funded Duke Superfund Basic Research Center (http://superfund.geneimprint.com/) and the Duke Global Health Institute (http://globalhealth.duke.edu/) , the symposium was chaired by Professor Ed Levin, Ph.D., director of the Training Core of the Duke University Superfund Research Center.
Thorne (http://www.public-health.uiowa.edu/peter-thorne-communicating-the-best-available-science/oehport039/) , a University of Iowa College of Public Health professor and director of the NIEHS-funded Environmental Health Sciences Research Center there, launched his exploration of "Bioaerosol Exposures and Asthma: Effects of a Changing Climate," with an account of his experiences during the "500-year" flood that ravaged Iowa along the Iowa River and Cedar River in the summer of 2008 - the second of its kind since 1993. Along with his work in New Orleans post-Katrina, Thorne said, the Iowa flood strengthened his conviction that "anthropogenic climate change [can] lead to more problems with flooding and indoor moisture levels such that we can expect a significant effect on asthma and allergy."
As Thorne explained, what the floods leave behind - including human sewage, animal waste, chemicals and toxic algae - creates microbial airborne hazards that can impact respiratory health through infectious bacteria and virus, inflammatory agents and mold allergens. Along the Gulf and in Iowa, the after-effects of the floods included an upsurge in asthma, allergy, and persistent chronic cough with flu-like symptoms related to contamination of indoor air with allergens and pathogens.
Models of the climate in the future point to an increase in such events and a friendlier environment for the triggers of respiratory disease. A wetter, warmer world with higher CO2 levels could mean an increase in mold- and pollen-producing biomass and a longer exposure season, as well as a greater vulnerability to extreme weather events that raise moisture levels.
Such weather events, triggering threats to health, happen all too frequently in south Asia, where Graziano (http://www.mailmanschool.org/msphfacdir/profile.asp?uni=jg24) and colleagues performed the fieldwork that underpinned his presentation, "Exposure Consequences and Remediation of Arsenic and Manganese in Bangladesh." Graziano is an associate dean for Research as well as a professor and the interim chair of the Department of Environmental Health Sciences at the Columbia University Mailman School of Public Health.
Graziano heads a binational group that pursued a multi-faceted, decade-long Superfund-supported research agenda in Bangladesh. The investigators studied 12,000 people to establish the extent of arsenic exposure from drinking water in shallow tube wells, the mechanisms of arsenic metabolism, the myriad direct and inter-generational health effects, and measures to protect residents from continued exposures to very high levels of arsenic. Based on the results of mapping wells and testing arsenic levels, the cross-disciplinary group crafted a novel strategy for remediation. The investigators later extended their research to elevated manganese concentrations found in the water from the wells, including those that are arsenic free.
The intervention involved drilling deeper wells to tap cleaner water below the arsenic and manganese reserves nearer the surface - work financed by an anonymous donor - encouraging people to switch wells when they could and launching an aggressive educational outreach campaign to translate study findings into preventive strategies. The team also discovered that folate supplementation facilitates arsenic methylation and elimination, thereby lowering blood arsenic levels.
In addition to Thorne and Graziano, the program (http://globalhealth.duke.edu/media/news/theres-hope-managing-toxic-risks-and-improving-global-health) included talks by Miriam Diamond, Ph.D., of the University of Toronto, Dan Costa, Ph.D., of the U.S. Environmental Protection Agency (EPA), Duke environmental economist Subhrendu Pattanayak, Ph.D., Jason Carver, of the U.S. Department of Agriculture, and Jeff Herndon, Ph.D., of the U.S. EPA.