We love subways, for they are the easiest and cheapest way to get around in big cities. And we hate subways for their urine smell, lurking rats, and pickpockets. But dirty rodents and the risk of losing your wallet are not the only dangers you can find under the ground.
Tons of people using subways every day leave germs that are not always friendly to your health. There is no reason to be afraid of every single germ; most of them live on your body, especially on your hands, and you do not even notice them. But the subway is a place where all the little invisible monsters accumulate and wait for you so they can attack.
So what can you actually catch under the ground apart from the awkward eye contact of a stranger?