Environmental concerns in a Globalized World: Japanese and American Sperm

 The number of boys in Japanese and American populations has declined in recent years, and some believe this is due to chemical polutants’ effects on sperm cells.

In the U.S., the proportion of boys dropped from 105.5 per 100 girls in 1970 to 104.6 in 2001; in Japan, the male-to-female ratio dropped from 106.3 boys for every 100 girls to just fewer than 105 per 100.

As one can see from these statistics, the decline in male versus female births is consistent in both the United States and Japan, therefore it can be hypothesized that this is not a cultural phenomenon. Rather, there most be some other causal factor.

Studies show that environmental pollutants are having a negative affect on the male reproductive system. Environmental toxins may affect the viability of sperm that bear the Y chromosome, which determines sex for male.

Indeed, environmental problems know no political boundaries, and the decline in male births on either side of the Pacific Ocean suggests that there is indeed some environmental toxin hindering the Y chromosome in sperm.

Source: http://news.yahoo.com/s/nm/20070416/hl_nm/male_births_dc_1