Environmental Health 2013, 12:63
doi:10.1186/1476-069X-12-63
Published: 15 August 2013
Published: 15 August 2013
Abstract
Background
The ratio of male to female offspring at birth may be a simple and non-invasive way
to monitor the reproductive health of a population. Except in societies where selective
abortion skews the sex ratio, approximately 105 boys are born for every 100 girls.
Generally, the human sex ratio at birth is remarkably constant in large populations.
After the Chernobyl nuclear power plant accident in April 1986, a long lasting significant
elevation in the sex ratio has been found in Russia, i.e. more boys or fewer girls
compared to expectation were born. Recently, also for Cuba an escalated sex ratio
from 1987 onward has been documented and discussed in the scientific literature.
Presentation of the hypothesis
By the end of the eighties of the last century in Cuba as much as about 60% of the
food imports were provided by the former Soviet Union. Due to its difficult economic
situation, Cuba had neither the necessary insight nor the political strength to circumvent
the detrimental genetic effects of imported radioactively contaminated foodstuffs
after Chernobyl. We propose that the long term stable sex ratio increase in Cuba is
essentially due to ionizing radiation.
Testing of the hypothesis
A synoptic trend analysis of Russian and Cuban annual sex ratios discloses upward
jumps in 1987. The estimated jump height from 1986 to 1987 in Russia measures 0.51%
with a 95% confidence interval (0.28, 0.75), p value < 0.0001. In Cuba the estimated
jump height measures 2.99% (2.39, 3.60), p value < 0.0001. The hypothesis may be tested
by reconstruction of imports from the world markets to Cuba and by radiological analyses
of remains in Cuba for Cs-137 and Sr-90.
Implications of the hypothesis
If the evidence for the hypothesis is strengthened, there is potential to learn about
genetic radiation risks and to prevent similar effects in present and future exposure
situations.
