Air Quality Index How Healthy is the Air You Breathe?

Air Pollution... Definition: The presence of one or more harmful chemicals in the atmosphere

Air Pollution... May cause harm to people, animals, vegetation, or materials, or may alter climate Concentration (quantity) and duration are determinants of level of harm

How Does Air Pollution Affect Us? Humans breathe in 6-10 liters of air per minute Harmful chemicals may be absorbed quickly without us being aware Air pollutants come into contact first with our respiratory systems, so the lungs are most affected by this pollution Air pollution may also affect the Heart Circulatory system Immune system

Who Does Air Pollution Affect? The very young are at risk Lungs are not fully developed until age 18 They have a faster breathing rate The very old are at risk May have undiagnosed lung or heart disease Pollution can exacerbate these conditions Persons with chronic illnesses, especially those with respiratory, circulatory, or cardiac disease, are also at risk

Does Air Pollution Affect Anyone Else? Yes, EVERYONE! Even healthy persons can be affected when they exercise outdoors, or if the concentration of pollutants is very high

How Do We Know When the Air is Polluted and Unsafe? Air pollution may be colorless or odorless, thus hard to detect Air pollution may be obvious, as a brown or yellow haze, or with particulates in the air By the time pollution is obvious, it may be at very unhealthy levels

What Causes Air Pollution? Nature Air pollution may occur due to natural processes volcanoesfires dust pollen & spores This pollution is dispersed over a wide area, and is usually not as hazardous as other pollution

What Else Causes Air Pollution? People! Air pollution may also occur due to human activities Called ‘anthropogenic’ sources Stationary sources, such as power plants or industry Mobile sources, such as vehicles

Because it is Sometimes Difficult to Know... To protect public health, the Environmental Protection Agency (EPA) monitors 5 air pollutants in what is called the ‘Air Quality Index’ (AQI) Ground-level Ozone (O ₃ ) Particulate Matter (Particle Pollution) < 2.5 microns < 10 microns Carbon Monoxide (CO) Sulfur Dioxide (SO ₂ ) Nitrogen Dioxide (NO ₂ )

How Values to Calculate AQI are Generated Monitors record the average concentration for each of the air pollutants The time recorded varies by pollutant In some circumstances, models are used to determine values for AQI

How AQI is Calculated An equation is used with the pollution concentration data and an AQI break-point table See for detailshttp:// AQI is calculated for each pollutant The pollutant with the highest AQI determines the level for the day, and is noted as the responsible pollutant

AQI Values AQI values range from The higher the AQI, the greater the air pollution and health concerns An AQI of 100 corresponds to the national air quality standard for that pollutant A value <100 is generally considered satisfactory and not a health hazard A value >100 indicates air quality may be unhealthy for some groups A value >300 represents very hazardous air quality

What are Common AQI Levels? AQI levels are generally in most U.S. communities AQI >100 may occur only a few times of year, if at all Some U.S. metropolitan areas have greater pollution and thus AQIs >100 AQIs >200 are rare in the U.S. In other countries with dense population areas, uncontrolled sources of pollution, and fewer governmental emission restrictions, AQIs are frequently >250

AQI Categories AQI values are converted to a category for easier understanding by the public Categories consider the public health impacts of the pollution level A color code is used to associate the actions to be taken at that level

AQI Chart

AQI Reporting Metropolitan Statistical Areas (MSAs) with populations >350,000 are required by Federal law to report the AQI daily to the general public

AQI Distribution AQI may be distributed: To media Newspapers Radio Television Provided as a recorded telephone message Published on an Internet site that is accessible to the public

The AQI Report Provides data on current day’s air quality and may include the next’s day’s air quality forecast MUST include: Reporting area Reporting period Critical pollutant AQI

The AQI Report MUST Also Include... Information on specific health concerns for certain populations Descriptor must be used: “Good” through “Hazardous” Color Code must be noted: “Green” through “Maroon” Cautions for sensitive groups for any pollutants with an AQI over 100

Pollutant Specific Sensitive Groups If AQI > Then these sensitive groups must be cautioned: Ozone People with lung disease, children, older adults, and people who are active outdoors PM2.5 People with heart or lung disease, children, and older adults PM10 People with heart or lung disease, children, and older adults CO People with heart disease SO ₂ People with asthma

Action Days ‘Action Days’ are called when the AQI is in the unhealthy range. Individual agencies/cities determine at what level to call ‘Action Days’ Some use ‘Unhealthy for Sensitive Groups’ or Code Orange Sensitive groups should avoid prolonged or heavy outdoor exertion outdoors Other cities use ‘Unhealthy’ or Code Red People should avoid prolonged or heavy outdoor exertion outdoors

Other Preventative Actions High levels of AQI may trigger various restrictions or prohibitions by local governments to protect the public health Officials consider: Current pollutant concentrations Prevailing weather conditions Forecasted weather conditions

Possible High AQI Actions Levels above 200 may cause an “Alert” stage Activities restricted may include incinerator use or open burning of leaves or refuse

Possible High AQI Actions Levels above 200 may cause an “Alert” stage Activities restricted may include incinerator use or open burning of leaves or refuse Levels above 300 may trigger a “Warning” stage Incinerator use may be prohibited, power plant operations cut back, specific manufacturing operations curtailed, and public driving limited with public transportation and carpooling encouraged

AQI Emergency Actions Levels above 400 would be an “Emergency” Would require most industrial and commercial activity to cease, and almost all private vehicle use to cease Death would occur in some very sensitive individuals Sensitive individuals might be hospitalized Healthy persons would probably experience symptoms that would restrict normal activities

Seasonal Variations in AQI Winter CO may be highest level pollutant Vehicle emission control systems do not operate as well in cold weather Levels are generally highest during morning or evening rush hours Summer VOCs and NOx form ozone more rapidly in the presence of heat and sunlight Levels peak in the afternoon

Smog/Ozone ‘Season’ Smog/Ozone ‘Season’ is generally May to September March 1- October 31 in Georgia Ozone may not be reported in other months unless the level is high or the ‘season’ is longer for that area

Ozone Standards EPA strengthened air quality standards for ground-level ozone in March, 2008 Ground-level ozone is a primary component of smog Lower levels of ozone are now reported as unhealthy in AQI and daily smog forecasts

Particle Pollution Maps Available year-round for some cities Some state and local agencies are not yet participating in this program

EPA Proposal for Stronger NO ₂ Air Quality Standards 06/29/2009 Proposal to update standards to reflect newest findings of NO ₂ exposure on public health Propose to monitor NO ₂ levels for a shorter time period Recent research indicates that short-term exposure to high NO ₂ levels, ranging from 30 minutes to 24 hours, may increase respiratory problems, especially in persons with asthma, children, or the elderly. Propose to monitor within 50 meters of major roadways in cities with at least 350,000 residents Often a higher concentration of NO ₂ near major roadways than at monitoring stations Proposal decision on new standard required by Jan. 22, 2010

Other Considerations AQI levels are not the only factors in determining how healthy the air is in a place- other factors include: Transportation patterns Industrial composition Location of monitoring sites Weather patterns, such as inversions

One Last Consideration... Synergism of pollutants has not been fully studied Combinations of pollutants may increase harmful effects Combinations of pollutants may cause harmful effects to occur at lower levels Combinations of pollutants may cause new or currently unknown problems EPA will likely modify the AQI as more research is available in this area

Air Quality Index (AQI) Summary The AQI is: Used to protect public health Used to determine appropriate activities for people, industry, and commerce Calculated from monitored values of 5 major pollutants An effective tool to determine how well Clean Air Act standards are being met by our communities