Monday, February 23, 2009

Clean air, safe food, and pure water

Clean air, safe food, and pure water were the focus of Friday’s symposium, entitled Managing Toxic Risks for Global Health. Presented by the Global Health Institute, the Superfund Basic Research Center and the Integrated Toxicology and Environmental Health program, the event drew attendees from across the region.

Following an introduction by Dr. Edward Levin and Dr. Michael Merson, scientists and researchers from a variety of areas addressed issues pertaining to the three major themes. Dr. Miriam Diamond began the symposium with a discussion of the interactions between science, policy, and politics in managing toxic material.

Clean air: The issues associated with air quality and human health were addressed by Dr. Daniel Costa of the US-EPA and Dr. Peter Thorne of the University of Iowa. Costa commented on the emergence of human-caused particulate matter in the air, while Thorne explained how bioaerosol exposure can lead to asthma.

Safe food: Jason Carver from the USDA-Foreign Agricultural Service discussed the global agricultural trade, and its implications for food safety. Dr. Jeff Herndon of the US-EPA spoke about how different countries can share information about the application of various pesticides, saving time and money.

Pure water: Duke’s own Dr. Subhrendu K. Pattanayak emphasized the relationship between adequate sanitation and drinking water quality. Improvements in sanitation can significantly reduce the incidence of waterborne disease, he said. In addition, he noted that “it’s absolutely imperative to pay attention to behavior change.” Simple measures such as boiling water and washing hands can go a long way in lowering a person’s risk of disease.

Developing countries carry most of the disease burden. Worldwide, 1.1 billion lack access to improved water supplies. Furthermore, 2.6 billion lack access to improved sanitation. There is certainly much room for improvement.

Why mobilize for sanitation? Pattanayak’s answer: Because children’s health will improve. Because women will achieve greater equality. Because if some people change their behavior, their peers might as well. Because a disease that exists in one country can always spread to another.

Also dealing with clean water, Dr. Joseph H. Graziano shared his research about exposure to naturally-occurring arsenic in well water, and how it can be remediated. The areas that are primarily affected are deltas that frequently flood. Graziano spent time in Bangladesh to research arsenic exposure there.

“140 million are chronically exposed [to arsenic] across many countries,” Graziano said. High levels of arsenic in the body are associated with painful skin lesions, diabetes, edemas, cancers, and cardiovascular problems.

People are affected to varying degrees, based on their ability to methylate arsenic into less-toxic dimethyl. According to Graziano, some people are just “better methylators,” and don’t get as sick. As for the rest? Graziano’s team found that people given 400 micrograms of folate every day became better methylators, and were able to flush much of the most toxic form of arsenic out of their systems.

Graziano’s team tested thousands of wells within a certain region of Bangladesh, and they found that deeper wells were much less likely to contain arsenic. The team labeled wells containing high levels of arsenic with signs to discourage their use, and made an effort to inform people about using alternate sources, such as deep wells and surface water.

“We know that we’ve helped these people,” Graziano said.

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