# 18.2. Our first data set: Air pollution in the United States¶

This first data set that we’re going to explore is from The Guardian’s data blog. They have a fascinating interactive map of all the cities in the world for which they have pollution data: http://www.theguardian.com/news/datablog/interactive/2014/may/08/exposure-air-pollution-city-map

We will use just the US data. There are three columns separated by colon (‘:’) characters:
• The city and state, separated by a comma.

• The annual mean amounts of particulate pollution that’s 10 micrometers in diameter, measured in terms of micrograms per cubic meter (ug/m3) of air. This is abbreviated as PM 10.

• The annual mean amounts of particulate pollution that’s 2.5 micrometers in diameter (even smaller), measured in the same micrograms per cubic meter of air. This is abbreviated as PM 2.5.

Here are just the first 9 lines of the data.

Aberdeen, SD :13 :8