Does nuclear radiation cause more boys to be born than girls? According to a new study, it certainly looks that way.

The study, published in the journal Environmental Science and Pollution Research, looked at the global dispersal of nuclear radiation in relation to the gender of babies born in certain locations throughout the world. Scientists analyzed population data for several decades for 39 European countries and the United States.

Under normal circumstances, male births outnumber female births by a ratio of 105 to 100. Nobody knows why, but that just seems to be the case. However, when researchers looked closely, they found an increase in the number of male births relative to female births in all of the countries from the period of 1964 to 1975 — and in many eastern European countries for several years after 1986. This increase was noted in all countries investigated and can be linked to the global dispersal of radioactive atoms from open-air atmospheric atomic bomb tests that were conducted until the early '60s.  

Another spike in male births was noted in relation to the 1986 Chernobyl disaster, but in this case, the effect was more localized. The closer the country was to Chernobyl, the stronger the effect. According to the study, more males were born relative to females in Belarus (near Chernobyl) than in France, and the effect was not noted at all in the United States.

So why would nuclear radiation cause more males to be born than females? Nobody really knows, but according to the study's authors, previous radiation experiments on animals suggest the boost in males may be due to damage to X chromosomes in sperm. 

Now all eyes are focused on Japan to determine whether or not the Fukushima Daiichi disaster will cause a similar effect in Japan or possibly even on the West Coast of the United States.

Nuclear radiation influences boy-to-girl ratio
New study finds that nuclear radiation from bomb tests and power plant accidents leads to the birth of more boys than girls.