Disposable face masks are not meant to be worn for more than a few hours, says Nachman. They get less effective over time, so after wearing one for a while, throw it out and put on a fresh one.

When two partners in a household both work and have no children, it is called "dual income, no kids" (DINK) Learn more about how the financial impact of DINKs.

But, Blaha says, interpreting the data is tricky, since young people change their preferences often, and, when surveyed, may not consider using disposable products such as “puff bars” as vaping. The ...