LITHIUM ALUMINUM-ALLOYS - A PROBLEM MATERIAL FOR BIOLOGICAL MONITORING

Investigations on aqueous and nonaqueous media have shown that the dust particles of lithium/aluminium alloy are readily soluble in blood serum. Concentration of 10 mg AI and 3 mg Li in 11 serum constitute the saturation values in human blood serum at 20-degrees-C. Further observations are intended to clarify the danger at the workplace. With a short-term exposure, the change in concentration of Li and AI was followed in the working environment and in the staff. Both elements (Li and AI) were determined in the working air, in the urine, the blood serum and on human skin with electrothermal AAS. On human skin, microerosions arise owing to hydrolytic destruction of the epidermis after long-term contact. The intensive irritant action of Li/AI dust is most relevant for preventive measures. It must also be considered that the AI values in the blood serum are raised by up to 50% in the presence of Li. The resorption and/or the bioavailability of AI is altered by Li. In the presence of Li up to a Li content of 2,5% in AI dust, a MAK (biological tolerance value, threshold limit value) of 1 mg AI/m3 room air (for the total dust) is recommended.