Particulate Matter Gets Around
Which particles do you think travel farther, PM10 or PM2.5?
How far do you think PM10 particles can travel: 100 feet, 25 miles or 500 miles?
How far do you think PM2.5 particles can travel?
The smaller particles are lighter and they stay in the air longer and travel farther. PM10 (big) particles can stay in the air for minutes or hours while PM2.5 (small) particles can stay in the air for days or weeks. And travel distance? PM10 particles can travel as little as a hundred yards or as much as 30 miles. PM2.5 particles go even farther; many hundreds of miles.
Particulate Matter and Your Health
Getting into your body.
When you inhale, you breathe in air along with any particles that are in the air. The air and the particles travel into your respiratory system (your lungs and airway). Along the way the particles can stick to the sides of the airway or travel deeper into the lungs.
The farther particles go, the worse the effect. Smaller particles can pass through the smaller airways. Bigger particles are more likely to stick to the sides or get wedged into one of the narrow passages deep in the lung.
Other factors that affect how deep into the lungs particles can go:
- Mouth or nose breathing. Breathing through your mouth allows particles to travel deeper into your lungs.
- Exercise. While exercising, particles can travel deeper.
- Age. Older people breath less deeply so particles may not get as deep.
- Lung disease. If lung diseases block the airway or cause shallow breathing, particles will stay in the upper sections of the airways and lung.
- Weather (temperature).
- Other pollutants in the air.
Your body responds to the particulate invasion!
Your lungs produce mucous to trap the particles, and tiny hairs wiggle to move the mucus and particles out of the lung. You may notice something in the back of your throat (this is the mucous); the mucous leaves the airway by coughing or swallowing. If the particle is small and it gets very far into the lungs, special cells in the lung trap the particles and then they can't get out and this can result in lung disease, emphysema, lung cancer.
Health Effects
Both PM10 (big) and PM2.5 (small) particles can cause health problems; specifically respiratory health (that's the lungs and airway). Because the PM2.5 travels deeper into the lungs AND because the PM2.5 is made up things that are more toxic (like heavy metals and cancer causing organic compounds), PM2.5 can have worse health effects than the bigger PM10.
Exposure to particulate matter leads to increased use of medication and more visits to the doctor or emergency room. Health effects include the following:
- Coughing, wheezing, shortness of breath
- Aggravated asthma
- Lung damage (including decreased lung function and lifelong respiratory disease)
- Premature death in individuals with existing heart or lung diseases
Particulate Matter - Air Quality Index (AQI) and Health Concerns
PM2.5 |
PM10 |
0 - 50 |
Good |
None |
None |
51 - 100** |
Moderate |
None |
None |
101 - 150 |
Unhealthy for Sensitive Groups |
People with respiratory or heart disease, the elderly, and children should limit prolonged exertion. |
People with respiratory disease, such as asthma, should limit outdoor exertion. |
151 - 200 |
Unhealthy |
People with respiratory or heart disease, the elderly, and children should avoid prolonged exertion; everyone else should limit prolonged exertion. |
People with respiratory disease, such as asthma, should avoid outdoor exertion; everyone else, especially the elderly and children, should limit prolonged outdoor exertion. |
* PM has two sets of cautionary statements, which correspond to the two sizes of PM that are measured:
- Particles up to 2.5 micrometers in diameter (PM2.5)
- Particles up to 10 micrometers in diameter (PM10)
** An AQI of 100 for PM2.5 corresponds to a PM2.5 level of 40 micrograms per cubic meter (averaged over 24 hours). While an AQI of 100 for PM10 corresponds to a PM10 level of 150 micrograms per cubic meter (averaged over 24 hours).