Systematic monitoring experiments of radon and gamma dose rate in air
were conducted at the site of the Nuclear Center of Mexico. The data w
ere obtained over a time period of 9 months during which a total solar
eclipse took place on 11 July 1991. The outdoor radon concentration w
as recorded with a continuous electronic radon monitor and with track
detectors. The gamma dose rate was measured with an ionization chamber
. The results show that the fluctuations of radon in air are influence
d by meteorological seasonal changes. Long-term variations in atmosphe
ric radon are correlated accordingly with those of the external temper
ature, while short-term radon determinations show an inverse correlati
on with temperature. The latter results are also discussed with respec
t to drastic short-term seasonal atmospheric changes and to the mild c
hanges resulting from the total solar eclipse. The observed gamma dose
rate shows geographic and temporal stability.