Wearing the same raw denim jeans for 15 months without washing seems to pose no health risks for healthy people, an Edmonton student and his professor have found.

Josh Le, who attends the University of Alberta, wore the skin-tight jeans from September 2009 to December 2010 to see how dirty raw denim jeans could get without washing.

Raw denim jeans have no chemicals traditionally used to treat materials.

At the end of the 15 months, Le and his human ecology professor Rachel McQueen swabbed the jeans for bacteria. They put the pants through a washing machine, after which Le wore the jeans another two weeks before re-testing.

The results surprised Le and McQueen. They found that the bacteria count on the freshly washed jeans was similar to the levels found in the prewashed sample.

In all, there were five kinds of skin bacteria in the jeans, and mostly in the crotch area, where between 8,500 and 10,000 bacterial units per square centimetre were found. However, McQueen said because Le was healthy, with no skin problems or cuts, there was no health concern.

Controlling odour was a different concern, Le said, admitting the jeans began to smell after a few months.

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(This survey is not scientific. It is based on readers' responses.)