Clemente Aguilar of the Medical Research Laboratory of the University Hospital San Cecilio in Granada, Spain, and Marieta Fernandez, Marina Lacasana and Nicolas Olea at the University of Granada say the study involved 280 students ages 18-23 from the University of Almeria.
The study found 18 pesticides in the blood of the study participants -- including some banned in Spain such as DDT and others legal in Spain such as the fungicide vinclozolin, used in vineyards and citrus groves.
All the study participants had at least one pesticide in considerable concentrations. The average number of pesticides detected in the blood tests was 11, the researchers say.
Exposure to some organochlorides proved to increase total spermatic number and total sperm motility levels, while other pesticides were associated with a reduction in sperm levels.
This might be due to the fact that some pesticides are considered to be slightly estrogenic endocrine disruptors -- substances that interfere with natural hormones in the body responsible for reproduction, development and/or behavior, the researchers say.
The study showed a strong correlation between exposure to vinclozolin and malformation rates in spermatozoa, but further experimental tests should be conducted for verification, the researchers say.