Biomedical Engineering

Distinguished Seminar Series: Mark Lyles

Dr. Mark Lyles, Chair, Medical Sciences and Biotechnology Center for Naval Warfare Studies Naval War College, Newport, Rhode Island Adj. Professor, Division of Biomaterials, Dept of Restorative Dentistry, Univ. of Texas Health Science Center at San Antonio, TX

“Medical Geology: Dust Exposure and Potential Health Risks in the Middle East”

In the Middle East, dust & sand storms are a persistent problem and can deliver significant amounts of micro-particulates via inhalation into the mouth, nasal pharynx, & lungs due to the fine size and abundance of these micro-particulates. The chronic and acute health risks of this dust inhalation have not been well studied nor has the dust been effectively characterized as to its chemical composition, mineral content, or microbial flora. Scientific experiments were designed to study the Kuwaiti & Iraqi dust as to its physical, chemical, and biological characteristics and for its potential to cause adverse health effects. First, dust samples from different locations were collected & processed & exposure data collected. Initial chemical & physical characterization of each sample including particle size distribution & inorganic analysis was conducted, followed by characterization of biologic flora of the dust, including bacteria, fungi and viruses.  Initial data indicates that the mineralized dust is composed of CaCO3 in a coating over a matrix of metallic silica crystals containing a variety of trace metals constituting ~1% of the PM10 by weight. The particles also consist of ~1% bioavailable Aluminum and reactive Iron each. Microbial analysis reveals a significant biodiversity of bacterial, fungi, and viruses of which ~30% are known pathogens. The level of total suspended particle mass along with environmental & physiological conditions present constitute an excessive exposure to micro-particulates including PM2.5 & the potential for long-term adverse health effects. These data suggest that the level of dust exposure coupled with the microbial & metal content could constitute a significant health risk. When taken with other existing work suggest that further immediate research is warranted to provide insight into potential human health risks both acute and chronic. Dr. Lyles will discuss the ongoing work in this area as well as the potential social, financial, and political ramifications emanating from such exposures.