Most of us, it seems, don’t know how to wash our hands. And that might be threatening our health.

A recent study by the U.S. Department of Agriculture found that 97 percent of consumers are failing to adequately wash their hands. That contributes to foodborne illness through cross-contamination of food and kitchen surfaces.

Part of the problem is that most people are in too much of a rush, failing to wash their hands for the necessary minimum of 20 seconds. A quick splash of soap and water just won’t do.

That’s a big deal because an estimated 48 million Americans get sick from foodborne illnesses every year. This leads to 48,000 hospitalizations and 3,000 deaths, particularly among the very young, the very old and those with compromised immune systems.

As USDA officials note, you can’t see, smell or feel bacteria. So, it’s all too easy to fall into bad habits and not realize the dangers posed by the microscopic world.

To see how the average consumer’s hand-washing habits, the USDA studied 400 people in six test kitchen facilities in urban and rural areas of North Carolina. The agency found that participants contaminated spice containers 48 percent of the time while preparing burgers. Refrigerator handles were contaminated 11 percent of the time. And about 5 percent of the time, salads were tainted by cross-contamination.

The solution is thankfully simple. Lather up hands with soap and water, being sure to get the back of the hands and in between fingers. Scrub for at least 20 seconds. Rinse. Then, dry hands with a clean towel.

And don’t skimp on that last step. An unrelated study shows that bacteria like E. coli huddle in wet, dirty towels.