In the Middle East, dust and sand storms are a persistent problem delivering significant amounts of mineralized particulates via inhalation into the mouth, nasal pharynx, and lungs. Recent reports suggest that this exposure can cause Constrictive Bronchiolitis in veterans.
Chemical composition, mineral content, or microbial flora of Kuwaiti and Iraqi dust was determined. Multiple site samples were collected and chemical and physical characterization including particle size distribution as well as identification of biologic flora to include bacteria, fungi and viruses was conducted.
The mineralized dust is composed of calcium carbonate over a matrix of metallic silicate nanocrystals containing a variety of trace and heavy metals constituting ∼3 % of the PM10 particles by weight, of which ∼1% each of bioaccessible aluminum and reactive iron. Microbial analysis reveals a significant biodiversity of bacteria and known pathogens. Of the microbes identified, several have hemolytic properties and most have significant antibiotic resistance. Viral analysis indicates a tremendous amount of virons with a large percent of RNA viruses. The level of total suspended particle mass at PM10 constitutes an excessive exposure micro-particulates including PM 2.5 (>1000 μg/m3). Cell culture and animal studies indicate a high level of toxicity. Lung biopsies show alveolar sacs filled with mineralized particles.
Taken together, these data suggest that at the level of dust exposure commonly found in the Middle East (i.e., Iraq, Kuwait, and Afghanistan), in addition to the microbial and metal content, mineralized dust constitutes a significant health risk, both acute and chronic, to deployed troops and native inhabitants.
- AAAAI 2015 (71st)