Air pollution is a problem in Debrecen, Hungary. A study was conducted on four types of Rosa species to determine their air pollution tolerance index (APTI). The study found that all four species had APTI values in the sensitive category. Rosa cherry amorina had the lowest APTI value of 9, followed by Rosa spinnaker amorina and Rosa roland garros amorina with 8, and finally Rosa red amorina with 7. The study concludes that these plants can be used to track air pollution levels and develop effective strategies to mitigate the problem.