PM2.5
Fine Particulate Matter
What is it?
Particles smaller than 2.5 micrometers in diameter. About 30 times smaller than a human hair.
Sources
Vehicle emissions, industrial processes, wood burning, wildfires
Health Effects
Can penetrate deep into lungs and bloodstream. Linked to heart disease, stroke, and respiratory issues.
PM10
Coarse Particulate Matter
What is it?
Particles smaller than 10 micrometers in diameter. Can be seen with the naked eye as dust or smoke.
Sources
Construction sites, unpaved roads, agriculture, crushing and grinding operations
Health Effects
Irritates airways, causes coughing, difficulty breathing, and aggravates asthma.
O₃
Ground-Level Ozone
What is it?
A gas formed when nitrogen oxides and volatile organic compounds react in sunlight.
Sources
Vehicle emissions, industrial facilities, gasoline vapors, chemical solvents
Health Effects
Triggers asthma, reduces lung function, inflames airways. Worse on hot, sunny days.
NO₂
Nitrogen Dioxide
What is it?
A reddish-brown gas with a sharp, harsh odor that forms from burning fuel.
Sources
Cars, trucks, buses, power plants, industrial boilers
Health Effects
Irritates airways, increases asthma symptoms, susceptibility to respiratory infections.
CO
Carbon Monoxide
What is it?
A colorless, odorless gas produced by incomplete burning of carbon-based fuels.
Sources
Vehicle exhaust, gas stoves, furnaces, generators, cigarette smoke
Health Effects
Reduces oxygen delivery to organs. Can cause dizziness, headaches, and at high levels, death.
SO₂
Sulfur Dioxide
What is it?
A gas with a strong odor produced from burning fossil fuels containing sulfur.
Sources
Coal-fired power plants, oil refineries, metal smelters, volcanoes
Health Effects
Irritates airways, triggers asthma attacks, contributes to acid rain formation.