The studies, published online today (Thursday 28 April) in Europe's leading reproductive medicine journal Human Reproduction, suggest that environmental pollutants could be changing the ratio of sperm carrying the X or Y (sex determining) chromosomes and that they could be contributing towards male reproductive disorders.
A study by Swedish researchers is the first to show that exposure to persistent organochlorine pollutants (POPs) can affect the distribution of sex chromosomes in sperm, leading to a slight increase in the number of sperm bearing the Y chromosome
Aleksander Giwercman, professor of andrology at the Scanian Andrology Centre, Fertility Centre, Malmö University Hospital, Lund University, Sweden, and his colleagues looked at the effect of two POPs (CB-153 and DDE) on semen in 149 Swedish fishermen, aged between 27 and 67, some of whom fished off the east coast in the contaminated Baltic Sea, while others fished off the west coast.
Prof Giwercman explained: "Closed aquatic ecosystems, such as the Baltic Sea, have become heavily polluted by POPs. In spite of decreases since the 1970s, this contamination has resulted in higher levels of POPs in humans, such as fishermen, who consume large quantities of local fatty fish."
POPs enter the environment in a number of ways. Tarmo Tiido, co-author and PhD student at the Fertility Centre, said: "The sources of contamination for POPs are closely related to human activities such as domestic and industrial discharge, automobile exhausts, street run-off, slum sewage and agricultural chemicals. POPs from polluted soils are washed off the land into the sea. Additionally, the atmosphere plays an important role in their transport over long distances. POPs have a strong tendency to bioaccumulate in marine and terrestrial food webs. Humans, being at the to
Source:European Society for Human Reproduction and Embryology