Hi Buuuuuula,
The affirmative statement would be -
Il y a de la pollution partout.
The negative would then become-
Il n'y a pas de pollution nulle part.
Take a look at the following lesson which explains how 'de la' becomes 'de' after pas:
https://kwiziq.learnfrenchwithalexa.com/revision/grammar/the-partitive-article-in-negative-sentences
Hope this helps!