By Jason DeRusha

MINNEAPOLIS (WCCO) — We take a shower and wash our hands because we want to get clean, but then we pick up the week-old crusty hand towel.

And some of us sleep in the same sheets and pillowcases for weeks.

READ MORE: Fabian Valdez Charged In Baseball Bat Attack Outside Burnsville Restaurant

So how often should we wash our towels, washcloths and sheets? And is leaving it unwashed that much of a danger?

“Yes, it is,” said Dr. John Hanlin, Vice President for Public Health at Ecolab, a St. Paul-based company specializing in cleaning products and technologies, among other businesses, in more than 160 countries.

“Towels, washcloths and sheets can become contaminated with bacteria, mold and viruses,” Hanlin said.

He said Ecolab’s clients are always seeking a balance: controlling mold and bacteria, along with prolonging the life of the linens.

“I encourage my family to hang towels and wash clothes properly to let them air-dry,” he said. “That will reduce the chance for bacteria to grow.”

Hanlin said that air drying makes the towel an unfriendly environment for bacteria, but only for so long.

READ MORE: 'I'm Not Mad At Derek Chauvin': George Floyd's Uncle Speaks Ahead Of Trial

One study looked at Turkish hand towels, and found one person using the same towel in the morning and night had a bacteria count of 3,800 on day one, 9,000 on day two, 17,800 by day three, and 83,000 by day four.

“We usually change ours every second or third day,” Hanlin said. “I don’t do it every day. You don’t need to do it every day.”

He said there is some logic to the idea that we are relatively clean when we use these towels, after showering.

But, “You get a combination of skin cells and a little bit of water,” he said. “A food source and water source, and these are all the right conditions for bacteria and mold to grow.”

He said that kitchen towels are even worse, and suggested changing those out every day.

“There’s so many bacteria in average kitchen, the risk of cross-contamination is high,” he said.

MORE NEWS: 'Fun And Memories': Hastings Man Spent Decades Perfecting Luge In His Yard

As for sheets, it’s not as serious of a concern, because sheets are typically in a dry environment. He suggested changing those out every week.

Jason DeRusha