Air Quality 

Index

Who Needs to Be 

Concerned? What Should I Do?

Good

(0-50)

No one. Air quality is good 

for everyone.

It’s a great day to be active outside!

Moderate

(51-100)

Some people may be 

unusually sensitive to 

particle pollution and may 

need to take precautions.

Unusually sensitive people: Consider reducing 

prolonged or heavy exertion. Watch for symptoms 

such as coughing or shortness of breath. These are 

signs to take it a little easier.

Everyone else: It’s a good day to be active outside!

Unhealthy for 

Sensitive Groups

(101-150)

Sensitive groups include 

people with heart or lung 

disease, older adults, 

children and teenagers.

Sensitive groups: Reduce prolonged or heavy 

exertion. It’s OK to be active outside, but take more 

breaks and do less intense activities. Watch for 

symptoms such as coughing or shortness of breath. 

People with asthma should follow their asthma 

action plans and keep quick relief medicine handy.

If you have heart disease: Symptoms such as 

palpitations, shortness of breath, or unusual fatigue 

may indicate a serious problem. If you have any of 

these, contact your heath care provider.

Unhealthy

(151-200)

Everyone can be affected. Sensitive groups: Avoid prolonged or heavy exertion. 

Consider moving activities indoors or rescheduling. 

Everyone else: Reduce prolonged or heavy exertion. 

Take more breaks during all outdoor activities. 

Very Unhealthy 

(201-300)

Everyone Sensitive groups: Avoid all physical activity outdoors. 

Move activities indoors or reschedule to a time when 

air quality is better. 

Everyone else: Avoid prolonged or heavy exertion. 

Consider moving activities indoors or rescheduling to 

a time when air quality is better.

Hazardous 

(301-500)

Everyone Everyone: Avoid all physical activity outdoors. 

Sensitive groups: Remain indoors and keep activity 

levels low. Follow tips for keeping particle levels low 

indoors. 

Air Quality Guide for Particle Pollution

Harmful particle pollution is one of our nation’s most common air pollutants. Use the chart below to help 

reduce your exposure and protect your health. For your local air quality forecast, visit www.airnow.gov
What is particle pollution?

Particle pollution comes from many different 

types of sources. Fine particles (2.5 micrometers in 

diameter and smaller) include power plants, industrial 

processes, vehicle tailpipes, woodstoves, and wildfires. 

Coarse particles (between 2.5 and 10 micrometers) 

come from crushing and grinding operations, road 

dust, and some agricultural operations.

Why is particle pollution a problem?

Particle pollution is linked to a number of health 

problems, including coughing, wheezing, reduced 

lung function, asthma attacks, heart attacks and 

strokes. It also is linked to early death.

Do I need to be concerned?

While it’s always smart to pay attention to air quality 

where you live, some people may be at greater risk 

from particle pollution. They include: 

•	 People with cardiovascular disease (diseases of 

the heart and blood vessels)

•	 People with lung disease, including asthma and 

COPD

•	 Children and teenagers

•	 Older adults 

•	 Research indicates that obesity or diabetes may 

increase risk.

•	 New or expectant mothers may also want to take 

precautions to protect the health of their babies. 

How can I protect myself?

Use AQI forecasts to plan outdoor activities. On 

days when the AQI forecast is unhealthy, take simple 

steps to reduce your exposure:

•	 Choose a less-strenuous activity

•	 Shorten your outdoor activities

•	 Reschedule activities

•	 Spend less time near busy roads

When particle levels are high outdoors, they can 

be high indoors – unless the building has a good 

filtration system. 

Keep particles lower indoors: 

•	 Eliminate tobacco smoke

•	 Reduce your use of wood stoves and fireplaces

•	 Use HEPA air filters and air cleaners designed to 

reduce particles 

•	 Don’t burn candles

Can I help reduce particle pollution? 

Yes! Here are a few tips. 

•	 Drive less: carpool, use public transportation, bike 

or walk 

•	 Choose ENERGY STAR appliances

•	 Set thermostats higher in summer and lower in 

winter

•	 Don’t burn leaves, garbage, plastic or rubber 

•	 Keep car, boat and other engines tuned 

Key Facts to Know About Particle Pollution:

•	 Particle pollution can cause serious health problems – including asthma attacks, heart attacks, strokes 

and early death. 

•	 Particle pollution can be a problem at any time of the year, depending on where you live.

•	 You can reduce your exposure to pollution and still get exercise! Use daily Air Quality Index (AQI) 

forecasts at www.airnow.gov to plan your activity.

Office of Air Quality and Radiation (6301A)

EPA-456/F-13-005

www.airnow.gov

November, 2013