This is the 17330th most frequent Polish word.
zanieczyszczeń
"Pollution" or "contaminants."
'Zanieczyszczeń' refers to the pollution or contamination that has increased, and it is in the genitive plural form to indicate its measurement or consideration.
W mieście zauważono wzrost zanieczyszczeń powietrza.
In the city, an increase in air pollution was noticed.
'Zanieczyszczeń' here specifies types of pollutants or contaminations being analyzed, appearing in the genitive plural due to the prepositional phrase.
Dokonywana jest analiza zanieczyszczeń wody w laboratorium.
An analysis of water pollution is performed in the laboratory.
'Zanieczyszczeń' functions to discuss the necessity of reducing pollutants, and again, it's used in the genitive plural to show relation to the action of reduction.