By Stephanie Stahl

PHILADELPHIA (CBS) — One of the best ways to guard against COVID-19 is to wear a face mask. Now, new research identifies the best kind and what’s most important about wearing a mask.

Any kind of facial covering in public is better than nothing. One of the studies says making sure your nose is covered is critical and the other says layers of material provide the best protection.

Carolyn Lyles was celebrating her 50th birthday at the Love statue with her mask was off only briefly for some photos. Otherwise?

“I cover up at all times,” Lyles said.

Research has shown cloth masks can stop up to 90% of droplets carrying the coronavirus. A new study says layers help.

Researchers used a light system and a high-speed camera for the study, where you can see the airborne droplets from people speaking, coughing, and sneezing while wearing no mask, a one-layer covering, two layers and a three-ply surgical mask.

“They showed that two layers is much better than one layer, and one layer is much better than nothing,” Professor Kimberly Prather, distinguished chair of atmospheric chemistry at the University of California San Diego, said.

Another study shows issues linked to not covering your nose and mouth. Yes, it’s hot in Philadelphia and breathing in a mask can be difficult, but they need to be worn correctly.

“If you don’t have it fitting to your face, things will just leak out and then they start to not be as effective,” Prather said.

This new research says COVID-19 is most likely to be spread from the nose. It found cells that line the nose were significantly more likely to become infected and shed the virus compared to the throat or lungs.

That’s why not wearing a mask correctly can be dangerous, demonstrated with a graphic from the Philadelphia Health Department.

“It may seem like a small difference to have it over your nose or not, but it can make a big difference in terms of the risk of spread of this virus,” Philadelphia Health Commissioner Dr. Thomas Farley said.

The health commissioner is reminding people about Philly’s mask-up campaign.

“Just to be a good neighbor, you know, just kind of to look out for people and also to protect my family and my kids,” Philadelphian Kate Barton said.

Research has also shown masks do not interfere with oxygen levels and that they’re safe for healthy people to wear.

But it’s also important to practice other safety measures, like social distancing and washing your hands.

Stephanie Stahl