SOME ASPECTS OF FALLOUT IN BRAZIL
FRANCISCO X, ROSER and THOMAS L. CULLEN*
Pontiffcia Universidade Catdédlica, Rio de Janeiro, Brazil
ABSTRACT
The Brazilian network of fallout stations ranges from the equator to
approximately 30°S and is composed of 10 ion-exchange column and
pot collection stations. At Rio de Janeiro the surface-air contamination is measured with filters. Three effects are discussedin this
paper: the spring maximum, the ocean—continent effect, and the correlation between filter and ion-exchange column data.
The spring maximum does not occur at equatorial stations where
there are only wet and dry seasons. It emerges slowly with increasing
latitude and is well marked in southern Brazil, but the effect is less
pronounced than in the northern hemisphere. Data from ocean, coastal,
and interior stations do not support the ocean—continent effect hypothesis. Comparison of column andfilter data for Rio de Janeiro shows
a positive correlation, but definite conclusions can be drawn only from
a study of many stations.
FALLOUT IN BRAZIL
The program of radioactivity measurements in Brazil was begun
in 1956 at the suggestion of the United Nations Committee on the Effects of Atomic Radiation. One branch of the work has centered on fall-
out, with rainfall collection samples processed at the AEC Health and
Safety Laboratory (HASL) in New York and with Staplex and Naval Research Laboratory (NRL) filters processed at Pontificia Universidade
Catdlica (Catholic University), Rio de Janeiro. The second branchof
the program concerns itself with the study of the Brazilian areas of
high natural radioactivity. This paper is concerned with three ques*Loyola Seminary, Shrub Oak, N. Y.
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