Vapor intrusion

Hi there! You know how sometimes when you make popcorn, you can smell it all over the house? That's because little tiny pieces of popcorn (called "popcorn vapors") float up into the air and go into your nose.

Well, buildings can also have vapors floating around inside them, but they're not from popcorn - they're from chemicals! These chemicals can be in the ground outside the building, like if there used to be a gas station or factory nearby.

If the building isn't sealed up tightly, these vapors can sneak inside through little cracks and things in the floor or walls. This can be bad because some of these chemicals are not good for people to breathe in - they could make people sick or cause problems with their brains or organs.

So, scientists and engineers try to figure out if there are vapors coming into a building and how to stop them. They might drill holes in the ground to test the air, or use special machines to suction the vapors out of the ground. They also make sure buildings are sealed up well to keep any vapors out.

And just like you might open a window to let the popcorn smell out of your house, sometimes buildings need to be vented to get rid of any vapors that might be inside.

So, that's what vapor intrusion is - it's when chemicals in the ground sneak into a building and scientists work to figure out how to keep people from breathing them in.