What are they?
There are two categories that make up mobile sources and they are the on-road vehicles and nonroad vehicles. Mobile sources is a term that describes a wide range of vehicles, engines, and equipment that generate air pollution which then travels from place to place.
On-road vehicles include:
Passenger Cars Buses
Pickup Trucks Delivery Trucks
Minivans Recreational Vehicles
Sport-Utility Vehicles Semi Trucks
Nonroad sources include:
Recreational Vehicles Ships
Construction Equipment Airport Service Equipment
Industrial Equipment Railway Maintenance Equipment
Lawn and Garden Equipment Recreational Marine Boats
Farm Equipment Aircrafts
Commercial Equipment Locomotives
How do mobile sources decrease air quality?
Once emitted, air pollution from mobile sources enters the atmospheric processes and reacts chemically with the light from the sun. The chemical reaction between air pollutants and the sun lead to a decrease in air quality. An illustration of atmospheric processes:
Source: United States Climate Change Science Program
What are the common mobile source air pollutants and how do mobile sources impact human health?
Common air pollutants emitted from mobile sources include:
Carbon Monoxide Particulate Matter
Hydrocarbons Air Toxics
Carbon Monoxide forms from incomplete fuel combustion mainly from vehicles. Carbon Monoxide reduces oxygen delivery to organs and tissues.
Hydrocarbons form from incomplete fuel combustion mainly in vehicles and also come from fuel evaporating. Hydrocarbons react with nitrous oxides to form ground-level ozone. Ground-level ozone is aggravates the respiratory system. Breathing becomes more difficult; ground-level ozone causes lung damage, and reduces cardiovascular functions.
Nitrous Oxides form when fuel burns at high temperatures in vehicles. Nitrous oxides chemically react with hydrocarbons, and light from the sun to form ground-level ozone.
Particulate Matter is a term used for liquid or solid particles that are found in the air. There are two categories of particulate matter: PM10 and PM2.5. PM10 has a diameter of 10 micrometers and PM2.5 has a diameter of 2.5 micrometers. Diameters of both particulate matters are able to penetrate the body’s natural filtering system. Once in the lungs, PM10 and PM2.5 may cause asthma, difficulty in breathing and chronic bronchitis especially in younger and older children. Particulate matter comes from both mobile and stationary sources.
Air Toxics are emitted from vehicles and there are several different forms of air toxics. Air toxics are known to cause cancer, and have reproductive and development side effects in newborns.
According to the EPA, “Today’s motor vehicles are still responsible for up to half of all the emissions released into the air.”
Metro East Community Air Project
1 Regency Plaza
Collinsville, IL 62234