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Air quality explained.

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Air quality is a measure of how clean or polluted the air is.

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The two main culprits of poor air

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quality are particulate matter and ground-level ozone.

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Particulate matter or airborne particles includes dust, dirt, soot,

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and smoke.

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These particles are so small that they

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can be inhaled causing serious health problems.

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The smallest are a fraction of the size of a human hair,

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even smaller than grains of sand.

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Ground-level ozone, on the other hand, is a gas and the main ingredient in smog.

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It forms when certain pollutants chemically react

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in the presence of heat and sunlight.

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Even low concentrations can trigger a variety of health problems.

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It can cause respiratory issues,

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hospitalization for heart or lung diseases, and even death.

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The EPA estimates that poor air quality causes more than 100,000 deaths in the US annually.

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Seniors, children,

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and those with compromised immune systems are especially at risk.

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How can you protect yourself?

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Outdoor activity and exercise of all kinds can help your heart stay healthy

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and resilient,

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but stay inside when the air quality is poor.

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If you must go out, limit your time outside.

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The air quality index, or AQI, reports the daily air quality.

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It tells you how clean or polluted your air is

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and what associated health effects might be a concern for you.

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See the current AQI for your area at airnow.gov.