What is the French 'pollution de l'air' in English?

Answer 1

"Air pollution" is an English equivalent of "pollution de l'air."

The feminine noun "pollution" takes as its singular definite article "la" ("the"), and as its singular indefinite article "une" ("a, one"). The preposition "de" means "of, from." The masculine noun "air" takes as its singular definite article "l"* and as its singular indefinite article "un."

The pronunciation is "poh-lyoo-syohn duh lehr."

*The masculine singular definite article actually is "le." But the vowel "e" of "le" drops before a noun that begins with a consonant. The temporary nature of that drop is indicated by an apostrophe.