Environmental pollutant can affect sex chromosomes

An environmental pollutant can alter the ratio of sperm carrying male and female chromosomes, according to a new study. A baby's sex is determined by X and Y chromosomes in the sperm. As the BBC http://www.bbc.co.uk reports, Swedish researchers found exposure to a class of pollutants which are a by-product of industrial and agricultural processes increased the Y chromosome sperms. However, the team, from Lund University http://www.lu.se , which studied 149 fishermen, were unable to predict if the effect would lead to more boys being born.