1 is the sun.
2,3 and 4 are clouds of pollution
5, 6 and 7 are people, unless you are a non-acting director.
Sc1 - sun is out (standing on chair?) people out walking enjoyng sunshine.
Sc2 enter cloud(s) each bearing name - cigarettes, traffic, industry, whatever. Sun blocked from people (gets down from chair) surrounded by clouds, possibly moved off stage.
people start coughing, spluttering, etc. one or all end up dead.
I don't know if it's a wonderful idea, but I hope it helps.