zero, received an exposure of 15 roentgens. A second tank driver,
also an Army sergeant, received an exposure of 3.3 roentgens. Three
members of the earth-sampling group, all of whom traveled in the tank
to ground zero, received exposures of 10, 7.5, and 5 roentgens. An
Army photographer who entered the test area six times between 23 July
and 20 October received 12.2 roentgens (1).

Four individuals involved with excavating the buried supports of the
TRINITY tower from 8 October to 10 October 1945 received gamma
exposures ranging from 3.4 to 4.7 roentgens. Film badge readings for
this three-day period indicate that the two individuals who operated
mechanical shovels received 3.4 and 4.3 roentgens, while the two who
supervised and monitored the excavation received exposures of 4.2 and
4.7 roentgens. The individual receiving 4.7 roentgens during the
excavation operation had received 1.3 roentgens from a previous
exposure, making his total exposure 6 roentgens (1).

An Army captain who accompanied all test and observer parties into the
ground zero area between 1 September and 11 October 1945 received a
total gamma exposure of 2.6 roentgens (1). The activities and times
of exposure are not known for other personnel with exposures over 2
roentgens.

According to the dosimetry records for 1946, about 115 people visited
the test site that year. No one ventured inside the fence surrounding
ground zero, and no one received an exposure greater than 1 roentgen
(1; 16).