Acid rain:

Increases the rate of weathering - Damaging buildings made of limestone or marble
Increases the rate of corrosion of metals
Makes soil acidic - Some crops find it hard to grow
Makes lakes acidic - Prevent fish eggs hatching
Kills fish and insects - Especially conifer trees

Nitrous oxides:

Incomplete combustion of fossil fuels:

Releases carbon monoxide - Which reduces the amount of oxygen the blood can carry
Releases particulate carbon - Which settles on objects and makes them dirty