The influence of the laboratory air quality on the precision and accuracy of elemental analysis at the lower trace/ultratrace levels has been investigated. Considerable variations were observed in a conventional laboratory for the periodic volt-ammetrlc measurement of standard solutions of selenium, copper, lead, zinc, nickel, and cobalt, owing to the variability of airborne contamination under this condition. However, the results obtained for cadmium were identical under clean room and conventional laboratory conditions. The sensitivity of the cathodic stripping voltammetry of selenium to other metal ions and the absence of analytical blank for this element provide a novel approach for monitoring the variability of airborne contamination in conventional laboratories. The effect of such variability on the precision and accuracy of trace element analysis is demonstrated for some biological and environmental samples.