Three of the first-year Mendenhall Fellows, Thomas L. Ziegler (Denver, CO), Christina A. Kellogg (St. Petersburg, FL), and Joseph E. Bunnell (Reston, VA), gave talks during the USGS Conference "Natural Science and Public HealthPrescription for a Better Environment" held in Reston from April 1 to 3. The meeting, which focused on the intersection of environmental research and human health, was a perfect showcase for their research.
While all three Mendenhall Fellows work in the Geologic Discipline, not one is a geologist! Thomas is a toxicologist by training, Chris is a molecular microbiologist, and Joe is a public-health biologist.
Joe presented his research first, in a talk titled "Environmental Predictors for Tick-Borne Disease Risk in the Middle Atlantic Region, USA." Lyme disease, the most common vector-borne disease in the United States, and ehrlichiosis, an emerging deadly disease, are both bacterial infections that are spread by ticks.
Chris discussed the long-distance transport of microbes in dust from the Sahara/Sahel region of Africa in her presentation titled "Out of Africa: Characterization of Microbial Communities Associated with Desert Dust and Their Implications for Human and Ecosystem Health."
Each year, millions of tons of desert soil dust blow off the west African coast and ride the trade winds across the Atlantic Ocean, routinely affecting the Caribbean and Southeast United States. This dust has been shown to carry living microorganisms, including a wide variety of bacteria and fungi, some of which are capable of causing disease in plants, animals, and humans with weakened immune systems. It is important to characterize and quantify these airborne microbes to assess what effects they may have on downwind ecosystems.
In his talk titled "Mineralogical, Geochemical, and Toxicological Variations of Asbestos Toxicological Standards and Amphibole Samples from Libby, MT," Thomas described how asbestos standards are not as uniform as one would expect.
In fact, the chemical analyses of a series of asbestos standards (amosites, anthophyllites, chrysotiles, crocidolites, and tremolites) indicated that elemental content varied within standards of the same mineral. Furthermore, each asbestos mineral, even those labeled as the same mineral, has its own profile of accessory minerals, which may play a role in the wide range of toxicity seen in the cell-line toxicity data presented and may possibly explain some of the conflicting reports for asbestos toxicity found in the literature. In addition, toxicity data were presented for the Libby, MT, amphibole that was revealed to be significantly more toxic than the asbestos standards.
In addition to the 20-minute talks given during the conference, both of the "out-of-towners" gave hour-long lectures about their Mendenhall research in the USGS Visitors Center: Thomas spoke the Monday before the conference, and Chris followed on the Friday after.
For more information on the Mendenhall program, including profiles of the Fellows and their research projects, please visit the Mendenhall Postdoctoral Research Fellowship Program Web site or contact Rama Kotra (firstname.lastname@example.org).
in this issue:
Mendenhall Fellows Lecture in Reston, VA