Agricultural pollution may reduce human sperm count

The researchers, from the US organisation Study for Future Families Research Group, investigated semen samples from the male partners of 512 pregnant women in Columbia, Missouri; New York City, Minneapolis, and Los Angeles between September 1999 and November 2001. The study revealed that sperm concentrations in Los Angeles, New York City, and Minneapolis were 38%, 75% and 67% higher than in Columbia, an area surrounded by agricultural land.

Sperm motility was also higher in the urban areas, and particularly higher in New York and Minneapolis, being 74% and 77% higher. The volume and percentage of normal sperm were not found to be reduced in Columbia.

Factors such as abstinence time, semen analysis time, age, race, smoking, history of sexually transmitted disease and recent fever, were taken into account, giving the researchers reason to believe that concentration and motility may be reduced in semi-rural and agricultural areas relative to those that are less agriculturally exposed.

A previous study carried out in Iowa City found sperm concentrations that were 18% lower than those found in Columbia. Johnson County – where Iowa City is located has nearly 290,000 acres of farmland, compared to nearly 250,000 acres in Boone County – where Columbia is located. Agricultural chemicals are applied to all or most of this farmland, according to the researchers.

The group is now examining urinary metabolite levels in relation to semen quality, and hopes to obtain funding to establish biomarkers of pesticide exposure on the entire study population. The study is published in the current edition of the journal, Environmental Health Perspectives.

On the other hand, living in cities is also bad for your health. A separate research project has found that older people living in urban areas in the US are significantly more likely to need medical treatment, particularly for lung problems. The research is published in the latest edition of the journal Health Affairs.