Pollution

Ground-Level Ozone | Particulate Matter

Ground-Level Ozone 

Ground-level ozone is the primary component of smog. It is created by a chemical reaction in the presence of sunlight.

Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. In addition, ground-level ozone can damage vegetation and ecosystems.

How Can I Reduce My Contribution to Ground-Level Ozone?

• Avoid idling your motor vehicle excessively (More than three minutes) 
• Conserve energy 
• Do not refuel your vehicle or lawn mower on days when high ozone levels are reported. If you must refuel, do so after sunset and before sunrise—remember that sunlight assists ozone-forming reactions
• Keep your vehicle well tuned
• Use public transportation
• Carpool, walk and ride a bicycle
• Drive efficiently by combining trips
• Do not use lighter fluid to start a charcoal grill

For more information on ground-level ozone visit:

• U.S. EPA’s Ground-Level Ozone Page 
• Montgomery County's Ground-Level Ozone Page   

Particulate Matter
"Particulate Matter," or PM2.5, is the term for a mixture of solid particles and liquid droplets found in the air. These particles come in many sizes and shapes and can be made up of hundreds of different chemicals. PM2.5 includes only fine particles with diameters that are 2.5 micrometers and smaller.

Sources of PM2.5 include power plants, industrial facilities, wood stoves, motor vehicles — especially older model diesel vehicles and equipment with two-stroke engines like some lawn mowers, weed whackers and chainsaws, because they burn oil.

Particle pollution such as PM2.5 can get deep into the lungs and cause serious health problems including:

• Increased respiratory symptoms, such as irritation of the airways, coughing, and difficulty breathing;
• Decreased lung function; 
• Aggravated asthma;
• Development of chronic bronchitis; 
• Irregular heartbeat; 
• Nonfatal heart attacks; and 
• Premature death in people with heart or lung disease.

In addition, particle pollution can have adverse environmental effects when it settles causing acidification of ponds and streams, changes to the nutrient balance in large river basins, depletion of the nutrients in soil and damage to sensitive forests and farm crops.

For more information on PM2.5:

• U.S. EPA’s Particulate Matter Page 
• Montgomery County’s Particulate Matter Factsheet