LOS ALAMOS NATIONAL LABORATORY
The Los Alamos Tip sheet is a monthly service for science journalists and editors 97-105
THIS WON'T HURT A BIT
Despite nationwide remediation efforts, lead poisoning still poses a significant public health problem. Recent data indicates that nearly 1.5 million preschool children have lead in their blood at nearly two times the upper limit recommended by Environmental Protection Agency and the Centers for Disease Control. Children may come in contact with lead in the soil, paint, water and food. Traditional methods are not sensitive enough to allow detection of lead amounts in the blood at new federally mandated levels and major efforts to increase the conventional technology's sensitivity have fallen short of expectations, Los Alamos researchers say. To achieve increased sensitivity in a reliable, economically feasible system, Los Alamos researchers have developed a selective laser technology known as resonant laser ablation and combined it with mass spectrometry to measure lead in environmental and biomedical samples. Laser ablation uses short pulses of high peak power to rapidly h! eat and vaporize a sample. Coupled with a mass spectrometer that measures the resultant molecular ionization, the new technology offers quick, noninvasive sample analysis in the parts per billion range, much more sensitive than the federal agencies require. Kathy DeLucas, (505) 665-9201, [email protected]
TAKING A CALCULATED RISK
There has been a chemical spill and the wind is picking up! The emergency response team needs to calculate a range of risk factors, including how the toxic plume may disperse and what potential dose and toxic concentrations might be expected. A new software program running on a hand-held calculator provides the answers. The program, called GAUS1, analyzes how plumes of gases and particles disperse in the atmosphere, settle on the ground and get lifted back into the air under different weather conditions. GAUS1 includes more parameters for meteorological and source conditions than are available with mainstream computing systems. When physical parameters such as source, the distance down-wind and surface roughness are entered, the program determines dispersion and deposition effects. The Los Alamos program can be used for training and for emergency response operations in the field. The program also can be applied to hazard evaluation, air pollution engineering, environmental imp! act assessment and education. Gary Kliewer, (505) 665-2085, [email protected]
ANOTHER BRIGHT IDEA
Los Alamos researchers have embarked on a project to develop and evaluate a new type of fluorescent light bulb. The new design replaces the cathode and mercury vapor gas present in conventional fluorescent bulbs with a novel carbon-fiber field emitter to produce energetic electrons that strike a special phosphor coating. Without the cathode damage caused by mercury gas, the design Los Alamos is exploring should last longer, offer higher electrical efficiency and be controllable for dimming with conventional circuitry. After the researchers develop and modify the field emitters that provide the energetic electrons in the bulb and produce the appropriate thin-film phosphors, they will combine those into a system to measure the brightness and efficiency of the bulb. John R. Gustafson, (505) 665-9197, [email protected]
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