Remote Real-Tiime Monitor for Elemental Speciation of Air Particules

Air particulates have been identified as a source of primary and secondary health risks. Even small, short-term increases in the amount of air particulate contamination in the atmosphere can produce significant increases in both mortality and morbidity from respiratory and cardiovascular diseases. For example, recent studies show that just two hours of breathing fine particles in a city from sources such as vehicle exhaust and smokestacks can increase the risk of heart attack by 44 percent. An example of an indirect health risk can be found in the highly toxic element mercury. It enters the environment principally from the burning of coal; gets dispersed by air particulates; contaminates soil, plants, and bodies of water; concentrates in the food chain; and finally, is ingested by humans. Because of the importance of air particulates, more than 5,000 air-particulate monitoring stations have been established in the United States (with perhaps four times as many internationally). Most measure the total amount (mass) of air particulate per volume of air, and more recently, the size distribution of particulate matter. A smaller network of monitoring stations performs chemical and elemental composition measurements, central to the particulate physical and biological effects. Most of these collect samples on filters that are transported to central laboratories for analysis. This research project is designed to provide near real-time, remotely accessed monitoring of toxic metal and other elemental contamination of air particulates. This will support monitoring for health advisories, research into medical and weather effects, and source attribution for the particulates. This approach is made possible by a novel and powerful new technology that uses proprietary doubly curved crystal x-ray optics developed by X-Ray Optical Systems, Inc. The general analytical technique, x-ray fluorescence (XRF), is the laboratory technique most widely used by U.S. Environmental Protection Agency monitoring stations. Advanced x-ray optics for collecting, concentrating, and improving the spectrum of the beam will enable the technique to be used for continuous monitoring in the field. This improved technique, microfocus monochromatic-excitation energy dispersive XRF, will improve the performance sufficiently that the field units may exceed the sensitivity of the current laboratory units for detecting toxic metal contaminates. The resulting analyzers will be compact, rugged, reliable, and low-cost enough to be widely distributed both in the United States and internationally (perhaps even allowing retrofit of existing air particulate monitors).