~ ™, s Page GB RRaS ALSO: a sS =e SOSA Te ws ~ * . =e ms . se at * ~ . - s tenMy New Haven Dustfai’. The Fe: coas of Exavbronmental Sanitation of the New Haven Department of Health collects monthly dust-fall samples at several stations in and around the city. The collectors are standard 1500 ml beakers, and duplicate samples are analyzed for dust content, one by evaporation of any rainfall and the other by filtration. The samples supplied to HASL were measured for total MFP activity and Sr-90, and the results are shown in Table 4. While the data are not as complete as desired, there are several interesting points, l. Filtration or evaporation are equally effective for dust-fall by weight. Be Filtration loses both MFP and Sr-90 by solubility. 30 the agreement in activity values between stations | is fairly good, and is independent of the dust-fall. A comparison of the mean Sr-90 values from the evaporated samples and the corresponding gummed film estimates (New Haven Airport) is shown in Teble k. It appears. that the gummed film rather than current tests, to give better agreement. cet ne tecoi Se! BIRRAR OR activity should have been attri buted to an early test-series,