  In a recent series of papers evidence has been presented for correlations
between solar activity and nuclear decay rates. This includes an apparent
correlation between Earth-Sun distance and data taken at Brookhaven National
Laboratory (BNL), and at the Physikalisch-Technische Bundesanstalt (PTB).
Although these correlations could arise from a direct interaction between the
decaying nuclei and some particles or fields emanating from the Sun, they could
also represent an "environmental" effect arising from a seasonal variation of
the sensitivities of the BNL and PTB detectors due to changes in temperature,
relative humidity, background radiation, etc. In this paper, we present a
detailed analysis of the responses of the detectors actually used in the BNL
and PTB experiments, and show that sensitivities to seasonal variations in the
respective detectors are likely too small to produce the observed fluctuations.
