Air pollution is the largest environmental risk to public health globally. 

Air pollution comes from a wide array of sources, both natural and caused by human activities.  

• Natural sources include:   
  • Volcanic eruption    
  • Soil and desert dust    
  • Wildfires    
  • Lighting      
• Human sources include:    
  • Power generation   
  • Transportation   
  • Industry    
  • Agriculture   

• People with pre-existing health conditions (e.g. cardiorespiratory)   
• Children and pregnant women  
• Elderly  
• Outdoor workers   

For more information on Health Effects of Air Pollutants on Vulnerable Populations, visit 
https://www.epa.gov/air-research/research-health-effects-air-pollution

• Ground-level ozone, the primary ingredient of smog, results from the chemical reactions of reactive organic gases and oxides of nitrogen in the presence of sunlight. The following equation represents smog formation:   
  • Reactive Organic Gases + Oxides of Nitrogen + Sun = Smog (Ozone)   

Air pollution can affect lung development and is implicated in the development of emphysema, asthma, and other respiratory diseases, such as chronic obstructive pulmonary disease (COPD).