"The towels we dry ourselves with get a lot of use and pick up a lot of microbes along the way. But how long should you wait before throwing them into the laundry?
The topic of towel washing might seem trivial, but Elizabeth Scott, a professor of biology and co-director of the Simmons University Center for Hygiene and Health in Home and Community in Boston, the US, is interested in what it can reveal about the way microbes spread around the home.
"They're not just naturally sitting around on towels," she says. "Anything that causes us harm on a towel is likely to have come from a human."
Jean-Yves Maillard, professor of pharmaceutical microbiology at Cardiff University, says practices like regular towel washing can help to reduce bacterial infections and in turn reduce the use of antibiotics. "Home hygiene is all to do with prevention, and prevention is better than treatment," says Maillard.
So, how often should we be washing our towels?
Scott suggests laundering towels once a week. However, this recommendation is not a set rule.
"It doesn't make a whole lot of sense because if someone is sick, they've got vomiting and diarrhoea," she says. "They need to have their own towel and those towels need to be laundered on a daily basis. That's what we call targeted hygiene, you deal with the risk as it occurs."
Scott refers to home hygiene as a form of altruism, much like vaccination. Each small practice you undertake to protect yourself, you also do to protect the people around you.
"We call it the Swiss cheese model," she says. "We think of all of these components as being slices of hygiene, like slices of Swiss cheese and every slice of hygiene covers up one of those holes and reduces the risk of pathogens being able to move through.
"Towels are a relatively small component, but there are definite risks with towels and it's easy to deal with that."