Can air pollution be caused by natural sources that are not man made?

Natural air pollution sources include:

• volcanoes (SO2, CO2, ash)
• forest fires (CO2)
• Pine forests (turpenes)
• dust storms (particlate)
• anaerobic decomposition (methane)
• lightning (ozone, NOx)
• ozone downwashing (ozone)
• natural gas leakage from underground formations (methane)
• carbon dioxide from underground formation (carbon dioxide)
• cattle (ruminant) burps and flatualnce