This is shocking!!

Just randomly checked the aqi air quality but this shocked me!! tbh idk very much about the air quality stuff and recently was going through these things... is this numbers very much normalised ? Cause 154 is quite high imo. What's your take on this?! Also what do you think might be the reasons for this poor air quality inspite of having good no of trees. I agree in mangalore city the trees are low in numbers but talking about overall dakshin kannada it's quite okayish not bad. And I checked same of new delhi and it was 136, again shocking!!