Fine Particulate Matter
PM2.5 · Measured in μg/m³
About PM2.5
Tiny particles less than 2.5 micrometers in diameter — about 30 times smaller than a human hair. They penetrate deep into the lungs and can enter the bloodstream. The most dangerous common air pollutant.
Sources
Vehicle exhaust, power plants, wildfires, industrial processes, wood burning
Health Effects
Heart attacks, irregular heartbeat, aggravated asthma, decreased lung function, premature death
EPA Standards
| Annual Standard | 12 μg/m³ |
| 24-Hour (Daily) Standard | 35 μg/m³ |
Frequently Asked Questions
What is Fine Particulate Matter?
Tiny particles less than 2.5 micrometers in diameter — about 30 times smaller than a human hair. They penetrate deep into the lungs and can enter the bloodstream. The most dangerous common air pollutant.
Where does PM2.5 come from?
The main sources of Fine Particulate Matter include: Vehicle exhaust, power plants, wildfires, industrial processes, wood burning.
What are the health effects of PM2.5?
Exposure to Fine Particulate Matter can cause: Heart attacks, irregular heartbeat, aggravated asthma, decreased lung function, premature death.
What is the EPA standard for PM2.5?
The EPA has set an annual standard of 12 μg/m³ and a 24-hour (daily) standard of 35 μg/m³ for Fine Particulate Matter.