What are the effects on people of Mt Popocatepetl?

None, really. The Popocatepetl volcano has been in a semi-dormant state for the past thousands of years; as such it has thrown incandescent material and pyrochlastic flows from time to time, but very few people have been killed by its eruptions.

Nowadays, more population around the volcano requires more security measures, such as evacuation routes and a contingency plan in case the volcano activity increases.