apart on the same ship, YAG 40-A (2 samplers) and YAG 40-B-7, collected. samples differing by a factor of 3. The evaluation of these collection biases is under study at this laboratory. Obviously, measures of total activity per unit area and perhaps of particle size are influenced by instrument and location biases. However, analyses for particle chloride content, water content, solids volume and activity values are of reasonable precision, These are parameters of individual particles and are not influenced by instrument biases, Applications The analytical techniques used here are directly applicable to a study of atmospheric sea salts, The similarity between the environmental interactions of naturally occurring particles and of slurry fallout is very striking. <A study of the former would yield useful information on environmental reactions of slurry fallout, Approved by: E, (R , q f, Svs “fk Roavy. J E.R. TOMPKINS Head, Chemical Technology Division For the Scientific Director -14- EEF £F rc inrikei*yr s: K EEEER fe UNCLASSIFIED