Air Quality Alert Issued For Weekend for Kentuckiana

Ozone is expected to return to the moderate range on Monday, though fine particle levels are expected to remain high.

Sensitive groups are defined as active children and adults as well as people with serious health conditions, such as asthma. Prolonged outdoor activity and physical exertion should be limited. Ozone levels generally peak during late afternoon and early evening hours.

The Air Quality Index, called the AQI, is a national standard used to report daily air quality. The AQI translates each pollutant measured into a common index. An index score of 100 equals the federal standard’s limit.

An Air Quality Alert is issued when particle pollution levels are expected to reach Unhealthy for Sensitive Groups range, which is an AQI of 101 or higher. Sensitive Groups include the elderly, children, persons with asthma or other breathing problems, and persons with heart disease. These groups are advised to limit their outdoor activities to reduce their exposure to particle pollution.

Particulate matter, or PM, is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. Particles of special concern to the protection of lung health are those known as fine particles, less than 2.5 microns in diameter. (For comparison, a human hair is about 75 microns in diameter.) Fine particles are easily inhaled deeply into the lungs where they can be absorbed into the bloodstream or remain embedded for long periods of time.

Ozone is a colorless, odorless gas and is the primary ingredient of smog. It is a form of oxygen with three oxygen atoms in every molecule (O3) instead of the two in the normal oxygen (O2) we need to live.

Ground-level ozone and particulate matter share peak months, May through August, as well as similar pollution sources - vehicles and industry. Again, as with ground-level ozone, the populations most vulnerable to particulate pollution include children, the elderly, and individuals with existing cardiovascular or lung diseases such as asthma and emphysema. Both fine particulates and ozone remain in the air for days and can travel hundreds of miles from their origins, spreading over large geographic regions.

Limit prolonged outdoor activity and physical exertion. Plan strenuous activities when particle levels are lower. Reduce the amount of time spent at vigorous activity, or choose a less strenuous activity, such as walking instead of jogging.

When particles are high outdoors, they may also be high indoors. Certain filters are available to help reduce particles indoors. You can reduce indoor particles by eliminating tobacco smoke, and reducing your use of candles, wood-burning stoves or charcoal grills.