SIOUX CITY, Iowa (KCAU) – In Monday’s Classroom 9 lesson, I will explain how snow becomes dirty when it falls through the air.

I’m sure most of you have made snow cream or grabbed a handful of snow and taken a bite of it, but have you ever thought about what’s in that snow?

As snow falls, it collects tiny particles in the air such as pollutants from factories and cars as well as dust floating around from farm fields.

The structure of snow acts almost like a net catching these particles as it falls.

The first snowflakes are the ones that catch the most particles since they’re the first ones to encounter the dirty air.

These first snowflakes are the dirtiest of the bunch before they hit the ground.

At the ground level, the wind will blow around the snow as well as dirt and different things at the ground.

The snow will then mix with different pollutants and particles at the ground making the snow even dirtier.

Urban areas with more factories and cars will also have dirtier snow than a rural area with less pollution.

Usually the last snowflakes that fall are the cleanest because they fall through the air that’s a bit cleaner compared to the first snowflakes.

So if you’re going to take a bite out of some snow, the best snow to eat would be the snow on top.

If it’s windy though, the snow on top could be mixed with dirty snow from the bottom.

You should be fairly safe eating snow, but just be mindful that chances are you’ll be eating some pollution as well!