Many atheletes are at risk of getting sprains, strains and scratches, now researches are finding that swimmers may be at risk of teeth stains.

According to a study published in the October issue of the Journal of the American Dental Association (JADA), young athletes who swim more than six hours per week in chemically treated pools may develop brown stains on their teeth.

Researches surveyed active swimmers between the ages of 6 and 18 across the United States and found that 58 percent of those who responded had brown stains on their teeth, "swimmers calculas."

A laboratory analysis of the brown tartar revealed that it differs from normal tartar stains most likely because of the chemicals that are found in swimming pools.

Swimming pools are chemically treated to maintain stringent water quality standards. It's thought that these chemicals combine with the swimmer's saliva to create this unusual brown staining.

The stains can usually be removed with a professional cleaning. But the researchers found that the stains, which usually occur on the front teeth, can return as soon as two months after a professional dental cleaning. The moral of the research is, active swimmers may need more frequent professional tooth cleanings.