This is the 13367th most frequent Turkish word.
kirliliğine
"Of its pollution" or "related to its pollution."
The word 'kirliliğine' refers to a possessive form indicating 'to the pollution' or 'of the pollution', used to specify the subject being paid attention to (in negative).
Endüstri devrimi sırasında hava kirliliğine dikkat edilmedi.
During the industrial revolution, air pollution was not taken into account.
Here, 'kirliliğine' denotes 'to the pollution' specifically pointing towards water pollution, as the matter in need of a solution.
Çevreciler su kirliliğine çözüm arıyor.
Environmentalists are seeking a solution to water pollution.
The usage of 'kirliliğine' signifies focus on 'to the pollution', in this case, of the sea, indicating the topic requiring action.