Special Report: How dirty are the surfaces you touch?

PHILADELPHIA (WPVI) -- Germs are everywhere.

This isn't a story to scare you from touching anything, because in some cases, germs are good for us. They help boost our immunity.

But there are some that can make you sick if you're not careful.

We set out to swab surfaces to find the dirtiest things.

Some things we expected to be dirty, but others surprised us.

Using a Hygiena luminometer, in just 15 seconds, it showed us the number of organisms on everyday surfaces.

Hospitals use Hygiena luminometers to monitor how clean or dirty spaces are.

In a patient's room the number should be under 50.

A nurses' station should read about 100 or less.

Food manufacturing equipment must be under 10.

But what about the keyboard at my desk?

We don't live in a hospital so we expected higher numbers, but what we found was surprising.

My keyboard read 779.

After cleaning it, it dropped to 341.

But that was nowhere near the worst.

We swabbed dozens of different surfaces in the city and the suburbs.

Here are our top four offenders:

#4 - A Bible.

They say cleanliness is next to Godliness, so we went undercover at a local church to test a bible. The reading was 975.

#3 - A parking kiosk.

The reading on the parking kiosk in Center City Philadelphia was 1,409.

#2 ATM

An ATM came in at 1,596.

#1 Playground slide

That's right. The #1 dirtiest thing we found was at a playground. The slide got a score of 2,392.

Here are the Top 10 Dirtiest Readings:

10 - Shopping Cart: 432

9 - Escalator: 482

8 -Walk Sign: 533

7- Restaurant Menu: 623

6- Mailbox: 669

5- Ali's Desk: 779

4- Bible: 975

3- Parking Kiosk: 1409

2- ATM: 1596

1- Playground Slide: 2392

But Dr. Henry Fraimow, an infectious disease expert at Cooper University Hospital, says many germs actually aren't dangerous.

"In fact, our bodies are covered with non-virulent bacteria and they're part of what makes us who we are," Fraimow said.

But that said, some harmful viruses and bacteria can survive on surfaces for at least a few hours.

If you touch one, then touch your mouth, nose or eyes, you could get sick and the risk is greater now.

"Especially as we move into cold and flu season and there's a lot more people with drippy noses and then are wiping their hands," Fraimow said.

To protect yourself, wash your hands, at least before preparing food, after using the restroom, and before and after you eat.

"And also just be aware, you don't want to be touching your face or sticking your hand in your nose or mouth unnecessarily when you've been touching other things outside of the house," Fraimow said.

If your immune system is compromised, then as you know, you can get sick much easier, so you have to be extra careful.

As for the cleanest things we found, we tested a dollar bill. It read 191.

And the #1 cleanest thing we found was a voting booth. Mine tested 91.

The voting officials had hand-sanitizer right outside the polling place.

That was a good idea.