Air pollution can damage plants in many ways, including:

Leaf damage: Ozone and other pollutants can damage leaf structure and function. Symptoms include stippling, flecking, bleaching, or dead areas. 

Reduced growth: Air pollution can reduce plant growth and crop yields. 

Photosynthesis: Air pollution can damage photosynthetic systems, which can lead to reduced growth. 

Reproductive issues: Air pollution can change reproductive success in plants. 

Stomata damage: Air pollutants can damage stomata, which are microscopic openings in leaves that control water loss and gas exchange. 

Acidification: Air pollutants like ammonia can contribute to acid deposition, which can damage crops, forests, and aquatic ecosystems. 

Heavy metals: Heavy metals can be transported long distances in the atmosphere and accumulate in food chains. 

Ozone: Ozone can obstruct leaf apertures, which can prevent plants from breathing and photosynthesizing. 

Nitrogen dioxide: High levels of nitrogen dioxide can reduce plant growth and crop yield.