Saving the environment while becoming radioactive

I had hoped to feature this chart in a more interesting composition but as I was getting ready to do the shot a security man came and told me I couldn't take photographs in the hospital grounds, so I have only this sneak pic of the chart itself on the iPad.
Bradford Royal Infirmary, where I was, has a sign posted walk around the grounds with a chart showing how many calories you can burn. So, while a long queue of cars belched pollutants into the atmosphere as they waited for an opportunity to get out into a busy road, I did the walk. I had two hours to spend while I became radioactive for the impressive Star Wars machine I was to mount later.
So this is my mono Monday blip for 'environment'.
Thanks to davidc for hosting Mono Monday.