Mass transit and swine flu

"I'm conscious about when people do sneeze if they're not covering their face," commuter Valerie Vargas said.

"Obviously in places where there's a lot of people, crowding, poor ventilation, your chances of exposure is much greater," Dr. Peter Wenger of University Hospital said.

Viruses can go airborne, settle on the poles, the handrails and the buttons you push.

"Then, the virus doesn't go thru your skin. What you do is essentially touch your face, your lips, your eyes, you do things like that," Wenger said.

That exposes you to the flu.

Click here to view the complete special, Swine Flu: A Dose of Reality

On Washington D.C.'s metro transit system, workers are sanitizing trains, buses, machines and stations more often right now.

But Dr. Wenger says the first line of defense for commuters should be both flu shots, seasonal and H1N1.

"By far, that's your best protection, whether you're on a bus or a train, whatever you're on," he said.

Millions of commuters live in the tri-state area. Many who won't get flu shots are riding systems that may not get the extra disinfection, so good hygiene is more important, like clean hands.

"I just wash my hands regularly and try not to have my hands all over everything," Tim Barbera said.

Dr. Wenger says hand sanitizers like convenient wipes are good to have in your pocket. They contain alcohol, which can actually kill viruses. If you're really concerned about airborne exposure, N-95 or painter's grade masks can give you more protection.

Wenger says a healthy lifestyle is an added benefit - eat well and sleep well, because exhaustion can suppress your immune system making it easier for the virus to attack.

"In addition, you're not as careful when you're sleepy. You're much more (rubbing your mouth and eyes) when you're sleepy," he said.

Taking preventive steps can keep your commute more healthy and fearless.