My angmoh is not very good but here's my opinions anyhow.
First sentence. In this case, you've used the verb form of epitome
when the correct form is its noun; epitome. Also, don't take it to
heart but this sentence is grammatically unstylish, though it's
essentially correct. "Due to the pollution" can be ommitted because
you've already stated the context(which, in this case is the
pollution). Otherwise, you're being redundant, an error most ppl
even experts make. Don't try to use big and important looking words
if you're not 100% familiar with them, it'll only serve to make you
look amateurish. In fact, good English is often the result of smart
play of grammar, not flowery words. Style is very important in
writing, you should note that.
Second sentence. Your tense is correct so no worries. However, you
can try the above mentioned methods to improve your sentence
structure. Post it here if you'd like to ! 
Cheers and have a nice day.
