Air Quality

Greater Philadelphia area residents and businesses are being asked to help efforts to reduce ground-level ozone on announced unhealthy air quality days.

What is Ozone?

Ozone is a noxious form of oxygen. Unlike ozone in the stratosphere which protects us from ultraviolet radiation, ground-level ozone can cause lung damage. Remember: Ozone is good up high but bad nearby! Elderly individuals, people with existing respiratory ailments such as asthma and emphysema, and young children should avoid strenuous activity on unhealthy air quality days. Even healthy adults exercising or working outdoors may experience lung problems on those days.

But ground level ozone is not the only way that pollution gets into the air.  There also is particule pollution.  Particle pollution — also called particulate matter (PM) — is made up of particles (tiny pieces) of solids or liquids that are in the air. These particles may include:

  • Dust
  • Dirt
  • Soot
  • Smoke
  • Drops of liquid

Some particles are big enough (or appear dark enough) to see — for example, you can often see smoke in the air. Others are so small that you can’t see them in the air.

Where does particle pollution come from? Particle pollution can come from two different kinds of sources — primary or secondary. Primary sources cause particle pollution on their own. For example, wood stoves and forest fires are primary sources. Secondary sources let off gases that can form particles. Power plants and coal fires are examples of secondary sources. Some other common sources of particle pollution can be either primary or secondary — for example, factories, cars and trucks, and construction sites.Smoke from fires and emissions (releases) from power plants, industrial facilities, and cars and trucks contain PM2.5.

Particle Pollution and Your Health

Breathing in particle pollution can be harmful to your health. Coarse (bigger) particles, called PM10, can irritate your eyes, nose, and throat. Dust from roads, farms, dry riverbeds, construction sites, and mines are types of PM10.  Fine (smaller) particles, called PM2.5, are more dangerous because they can get into the deep parts of your lungs — or even into your blood.


The objective of the Air Quality Partnership is to decrease the formulation of ground-level ozone during the summer. Ground-level ozone forms when pollutants from vehicles, paints and solvents, unburned fuel, and industrial sources "bake" in hot, sunny weather.  The program warns the public about forecasted high ozone days, and asks for voluntary actions to reduce emissions of ozone-forming pollutants. The Air Quality Partnership program is entirely voluntary and depends on everyone to share the responsibility. The program is cost-effective and does not require new regulations or mandatory actions.

There are a variety of easy ways people can participate, such as these:

  • Limit daytime driving and combine errands
  • When you must drive, try to avoid congested periods
  • Ride public transportation or carpool to work
  • Maintain your vehicle's emission control equipment
  • Walk or ride a bicycle for short trips
  • Postpone the use of gasoline-powered mowers until evening
  • Refuel your car in the evening and don't top off your tank
  • Avoid lighting your barbecue with starter fluid
  • Avoid prolonged idling and jackrabbit starts
  • Use latex rather than oil-based paints



The program is sponsored by a variety of business, environmental and government partners and is managed by the Delaware Valley Regional Planning Commission (DVRPC).

For more information about the program, please contact The Partnership TMA 215-997-9100 or DVRPC 215.592.1800.

A Special Thanks to Our Sponsors

SEPTA   |   PennDOT   |   DVRPC   |   Montgomery County