Air Quality Index

The Air Quaility Index (AQI)) was developed by the United States Environmental Protection Agency (USEPA) to generate consistency in reporting air quality throughout the country.

Ohio's Air Quality Index (AQI), was designed to make it easier to understand air quality from state to state and region to region.

The AQI system places maximum emphasis on protecting the public health. Therefore, the numbers and terms describe the health effects of the various air pollution levels. In addition, cautionary statements will be used when the AQI value exceeds 100. See Chart Below.

The AQI is based on a scale of 0 - 500. Readings below 100 mean the air quality is within the standards. Readings above 100 mean the air is above the standard and is potentially unhealthful. At the 200 level, a first stage alert would be issued by the state. At 300, a second stage alert would be called and at 400, the third stage would be declared.

The AQI is designed to include any of the five main pollutants; suspended particulates, sulfur dioxide, photochemical oxidants, nitrogen dioxide and carbon monoxide. As readings are taken for these pollutants, the daily AQI is given as the highest index value of any of the five. For example, if sulfur oxides and particulates were monitored daily, the pollutant having the higher index reading would determine the index for that day.

Approximately 150 media sources throughout Ohio carry the AQI. If your news source does not report the AQI, you can obtain it by calling your local air pollution control office or local Ohio EPA district office.

Below is a list of all the criteria pollutants monitored by the Lake County General Health District. From the data collected, we calculate a Air Quality Index (AQI). On each of the pages, you can also obtain additional information on each instrument that analyzes the criteria.

Health Warnings and Effects

API	Health Category	Warnings	Action
0 -50	Good	None	None
51-100	Moderate	Caution	Caution
101-150	Unhealthy for Certain Groups	Mild aggravation of symptoms in susceptible persons, with irritation symptoms in the healthy population. Persons with existing heart or respiratory ailments should reduce physical exertion and outdoor activity.	Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion
151-200	Unhealthy	Mild aggravation of symptoms in most persons, with irritation symptoms in the healthy population. Persons with existing heart or respiratory ailments should reduce physical exertion and outdoor activity.	Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion.
201-300	Very Unhealthy	Significant aggravation of symptoms and decreased exercise tolerance in persons with heart or lung disease, with widespread symptoms in the healthy population. Elderly and persons with existing heart or lung disease should stay indoors and reduce physical activity.	Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else especially children, should limit outdoor exertion.
301-500	Hazardous	Premature onset of certain diseases in addition to significant aggravation of symptoms and decreased exercise tolerance in healthy persons. Elderly and persons with existing disease should stay indoors and avoid physicalexertion. General population should avoid outdoor activity.	Everyone should avoid all outdoor exertion.