hol2 Monthly Sr?° Levels in Liquid Milk from New York City
Beginning in June 1954, a quart of liquid milk was purchased

five days a week from a store near HASL.

The labeled brands were varied

to avoid sampling milk from particular farms.

The daily samples were

combined, evaporated to dryness, ashed and analyzed as a weekly sample.
Since January 1957, the daily samples have been combined to
form a monthly composite.
Table 12 summarizes data in ye Sr90/g Ca.
graphed in Figure 8.

The data are

The values through May 1956 represent monthly

averages of weekly analyses.

Since January 1957, the values represent

averages of replicate analyses made on monthly composites.

In both

cases, the error term represents one standard deviation from the meane
From June through December 1956, no liquid milk samples were

analyzed.

This program was resumed after it was recognized that the

powdered milk samples from Perry, New York did not represent the New
York City milkshed.

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