Technology is on the rise, and with that comes industries. With industries, comes factories. With factories comes some pollution.
Factories, however, are necessary for cities to strive.
Science is not too advanced, but I'll say that as of now, Eizon is in a new era of industries. Industries provide jobs and power for cities. In fact, I'd say Eizon would be in the later 1800's - early 1900's in terms of technology.
Make use of the knowledge.