Air quality is defined as a measure of the condition of air relative to the requirements of one or more biotic species and or to any human need or purpose.[1]
An air quality measurement station in Edinburgh Edinburgh (pronounced /ˈɛdɪnbɹə/ ( listen), ED-in-brə or ED-in-bə-rə) (Scots: Edinburgh/Embra/Emburrie) (Gaelic: Dùn Èideann) is the capital city of Scotland, the second largest city in Scotland after Glasgow and the seventh-most populous in the United Kingdom. The City of Edinburgh Council is one of Scotland's 32 local government, Scotland Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the southwest. In addition to the mainland, ScotlandThe Air Quality Index (AQI) (also known as the Air Pollution Index (API) or Pollutant Standard Index (PSI) is a number used by government agencies to characterize the quality of the air at a given location. As the AQI increases, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects. To compute the AQI requires an air pollutant concentration from a monitor or model. The function used to convert from air pollutant concentration to AQI varies by pollutant, and is different in different countries. Air quality index values are divided into ranges, and each range is assigned a descriptor and a color code. Standardized public health advisories are associated with each AQI range. An agency might also encourage members of the public to take public transportation or work from home when AQI levels are high.
Contents |
Limitations of the AQI
Signboard in Gulfton, Houston Houston is the fourth-largest city in the United States of America and the largest city in the state of Texas. As of the 2009 U.S. Census estimate, the city had a population of 2.3 million within an area of 579 square miles (1,500 km2). Houston is the seat of Harris County and the economic center of the Houston–Sugar Land–Baytown metropolitan indicating an ozone Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2). Ozone in the lower atmosphere is an air pollutant with harmful effects on the respiratory systems of animals and will burn sensitive plants; however, the ozone layer in the upper watch| This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be and removed. (July 2010) |
Most air contaminants do not have an associated AQI. Many countries monitor ground-level ozone Ozone is a constituent of the troposphere (it is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer). Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human, particulates Particulates, alternatively referred to as particulate matter or fine particles and also called soot, are tiny subdivisions of solid or liquid matter suspended in a gas or liquid. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Air pollution and water pollution can take the, sulfur dioxide Sulfur dioxide is the chemical compound with the formula SO2. It is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one, carbon monoxide Carbon monoxide , also called carbonic oxide, is a colorless, odorless and tasteless gas which is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions and nitrogen dioxide Nitrogen dioxide is the chemical compound with the formula NO2. One of several nitrogen oxides, NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent air pollutant. Nitrogen dioxide is a and calculate air quality indices for these pollutants.
Causes of Poor Air Quality
The AQI can worsen (go up) due to lack of dilution of air emissions by fresh air. Stagnant air, often caused by an anticyclone An anticyclone is a weather phenomenon defined by the National Weather Service's glossary as "A large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere". Effects of surface-based anticyclones include clearing skies as well as or temperature inversion In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to a temperature inversion, i.e., an increase in temperature with height, or to the layer within which such an increase occurs, or other lack of winds Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space. Winds are commonly classified by their spatial lets air pollution Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment into the atmosphere remain in a local area.
Indices by location
Canada
The current health classifications used by the Meteorological Service of Canada The Meteorological Service of Canada is a division of Environment Canada, which primarily provides public meteorological information and weather forecasts and warnings of severe weather and other environmental hazards. MSC also monitors and conducts research on climate, atmospheric science, air quality, water quantities, ice and other (MSC) are as follows:
| API | Air Quality Level | Health Implications |
|---|---|---|
| 0 - 25 | Good | In Ontario Ontario is bordered by Manitoba on its west, Hudson Bay on its north, and Quebec on its east, and by five states of the United States to its south : Minnesota, Michigan, Ohio, Pennsylvania (Lake Erie) and New York. All but a small portion of Ontario's 2,700 km (1,677 mi) border with the United States follow inland waterways: from the west at Lake, 31 is the upper limit for good and 32 the lower limit for moderate. Zero to 15 is classified as very good, and is given the color blue. |
| 26 - 50 | Fair | |
| 51 - 100 | Poor | |
| 100 + | Very Poor |
Hong Kong
The Air Pollution Index (API) levels for Hong Kong are related to the measured concentrations of ambient respirable suspended particulate (RSP), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3) and nitrogen dioxide (NO2) over a 24-hour period based on the potential health effects of air pollutants.
An API level at or below 100 means that the pollutant levels are in the satisfactory range over 24 hour period and pose no acute or immediate health effects. However, air pollution consistently at "High" levels (API of 51 to 100) in a year may mean that the annual Hong Kong "Air Quality Objectives" for protecting long-term health effects could be violated. Therefore, chronic health effects may be observed if one is persistently exposed to an API of 51 to 100 for a long time.
"Very High" levels (API in excess of 100) means that levels of one or more pollutant(s) is/are in the unhealthy range. The Hong Kong Environmental Protection Department provides advice to the public regarding precautionary actions to take for such levels.
| API | Air Pollution Level | Health Implications |
|---|---|---|
| 0 - 25 | Low | None expected. |
| 26 - 50 | Medium | None expected for the general population. |
| 51 - 100 | High | Acute health effects are not expected but chronic effects may be observed if one is persistently exposed to such levels. |
| 100 - 200 | Very High | People with existing heart or respiratory illnesses may notice mild aggravation of their health conditions. Generally healthy individuals may also notice some discomfort. |
| 201 - 500 | Severe | People with existing heart or respiratory illnesses may experience significant aggravation of their symptoms. There may also be widespread symptoms in the healthy population (e.g. eye irritation, wheezing, coughing, phlegm and sore throats). |
Mainland China
China's Ministry of Environmental Protection (MEP The Ministry of Environmental Protection of the People's Republic of China , formerly State Environmental Protection Administration (SEPA, simplified Chinese: 国 ) is responsible for measuring the level of air pollution in China. As of 28 August 2008, MEP monitors daily pollution level in 86 of its major cities. The API level is based on the level of 5 atmospheric pollutants, namely sulfur dioxide Sulfur dioxide is the chemical compound with the formula SO2. It is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one (SO2), nitrogen dioxide Nitrogen dioxide is the chemical compound with the formula NO2. One of several nitrogen oxides, NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent air pollutant. Nitrogen dioxide is a (NO2), suspended particulates Particulates, alternatively referred to as particulate matter or fine particles and also called soot, are tiny subdivisions of solid or liquid matter suspended in a gas or liquid. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Air pollution and water pollution can take the (PM10), carbon monoxide Carbon monoxide , also called carbonic oxide, is a colorless, odorless and tasteless gas which is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions (CO), and ozone Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2). Ozone in the lower atmosphere is an air pollutant with harmful effects on the respiratory systems of animals and will burn sensitive plants; however, the ozone layer in the upper (O3) measured at the monitoring stations throughout each city.[2]
API Mechanics An individual score is assigned to the level of each pollutant and the final API is the highest of those 5 scores. The pollutants can be measured quite differently. SO2, NO2 and PM10 concentration are measured as average per day. CO and O3 are more harmful and are measured as average per hour. The final API value is calculated per day.
The scale for each pollutant is non-linear, as is the final API score. Thus an API of 100 does not mean twice the pollution of API at 50, nor does it mean twice as harmful. While an API of 50 from day 1 to 182 and API of 100 from day 183 to 365 does provide an annual average of 75, it does not mean the pollution is acceptable even if the benchmark of 100 is deemed safe. This is because the benchmark is a 24 hour target. The annual average must match against the annual target. It is entirely possible to have safe air every day of the year but still fail the annual pollution benchmark.[2]
API and Health Implications (Daily Targets)[2]
| API | Air Pollution Level | Health Implications |
|---|---|---|
| 0 - 50 | Excellent | No health implications |
| 51 -100 | Good | No health implications |
| 101-150 | Slightly Polluted | Slight irrations may occur, individuals with breathing or heart problems should reduce outdoor exercise. |
| 151-200 | Lightly Polluted | Slight irrations may occur, individuals with breathing or heart problems should reduce outdoor exercise. |
| 201-250 | Moderately Polluted | Healthy people will be noticeably affected. People with breathing or heart problems will experience reduced endurance in activities. These individuals and elders should remain indoors and restrict activities. |
| 251-300 | Heavily Polluted | Healthy people will be noticeably affected. People with breathing or heart problems will experience reduced endurance in activities. These individuals and elders should remain indoors and restrict activities. |
| 300+ | Severely Polluted | Healthy people will experience reduced endurance in activities. There may be strong irritations and symptoms and may trigger other illnesses. Elders and the sick should remain indoors and avoid exercise. Healthy individuals should avoid out door activities. |
Mexico
Main article: Índice Metropolitano de la Calidad del AireThe air quality in Mexico In Pre-Columbian Mesoamerica many cultures matured into advanced civilizations such as the Olmec, the Toltec, the Teotihuacan, the Zapotec, the Maya and the Aztec before the first contact with Europeans. In 1521, Spain conquered and colonized the territory, which was administered as the viceroyalty of New Spain which would eventually become Mexico is reported in IMECAs. The IMECA is calculated using the measurements of average times of the chemicals ozone Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2). Ozone in the lower atmosphere is an air pollutant with harmful effects on the respiratory systems of animals and will burn sensitive plants; however, the ozone layer in the upper (O3), sulphur dioxide Sulfur dioxide is the chemical compound with the formula SO2. It is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one (SO2), nitrogen dioxide Nitrogen dioxide is the chemical compound with the formula NO2. One of several nitrogen oxides, NO2 is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent air pollutant. Nitrogen dioxide is a (NO2), carbon monoxide Carbon monoxide , also called carbonic oxide, is a colorless, odorless and tasteless gas which is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal biological functions (CO) and particles lower than 10 micrometers (PM10).
Singapore
Singapore Singapore, officially the Republic of Singapore, is an island country off the southern tip of the Malay Peninsula, 137 kilometres north of the equator, in the Southeast Asian region of the Asian continent. It is separated from Malaysia by the Straits of Johor to its north, and from Indonesia's Riau Islands by the Singapore Strait to its south. A uses the Pollutant Standards Index The Pollutant Standards Index, or PSI, provides a uniform system of measuring pollution levels for the major air pollutants. It is based on a scale devised by the United States Environmental Protection Agency to provide a way for broadcasts and newspapers to report air quality on a daily basis to report on its air quality.[3] The PSI chart below is grouped by index values and descriptors, according to the National Environment Agency.[4]
| PSI | Descriptor | General Health Effects |
|---|---|---|
| 0 - 50 | Good | None |
| 51 - 100 | Moderate | Few or none for the general population |
| 101 - 200 | Unhealthy | Mild aggravation of symptoms among susceptible persons i.e. those with underlying conditions such as chronic heart or lung ailments; transient symptoms of irritation e.g. eye irritation, sneezing or coughing in some of the healthy population. |
| 201 - 300 | Very Unhealthy | Moderate aggravation of symptoms and decreased tolerance in persons with heart or lung disease; more widespread symptoms of transient irritation in the healthy population. |
| 301 - 400 | Hazardous | Early onset of certain diseases in addition to significant aggravation of symptoms in susceptible persons; and decreased exercise tolerance in healthy persons. |
| Above 400 | Hazardous | PSI levels above 400 may be life-threatening to ill and elderly persons. Healthy people may experience adverse symptoms that affect normal activity. |
South Korea
The Ministry of Environment of South Korea uses the Comprehensice Air-quality Index (CAI) to describe the ambient air quality based on health risk of air pollution. The index aims to help the public easily understand air quality level and protect the health of people from air pollution. - The CAI has values of 0 through 500, which are divided into six categories. The higher the CAI value, the greater the level of air pollution. - Of values of the five air pollutants, the highest is the CAI value.
For more information on the CAI please go here http://eng.airkorea.or.kr/cai/main.jsp
| CAI | Description | Health Implications |
|---|---|---|
| 0-50 | Good | A level that will not impact patients suffering from diseases related to air pollution. |
| 51-100 | Moderate | A level which may have a meager impact on patients in case of chronic exposure. |
| 101-150 | Unhealthy for sensitive groups | A level that may have harmful impacts on patients and members of sensitive groups. |
| 151-250 | Unhealthy | A level that may have harmful impacts on patients and members of sensitive groups (children, aged or weak people), and also cause the general public unpleasant feelings. |
| 251-350 | Very unhealthy | A level which may have a serious impact on patients and members of sensitive groups in case of acute exposure. |
| 351-500 | Hazardous | A level which may need to take emergency measures for patients and members of sensitive groups and have harmful impacts on the general public. |
United Kingdom
AEA Technology issue air quality forecasts for the UK on behalf of DEFRA The Department for Environment, Food and Rural Affairs is the government department responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities in the United Kingdom. Concordats set out agreed frameworks for co-operation between it and the Scottish Government, the Cabinet of the National wherein the level of pollution is described either as an index (ranging from 1 to 10) or as a banding (low, moderate, high or very high). These levels are based on the health effects of each pollutant.
| Index | Banding | Health Effect |
|---|---|---|
| 1 - 3 | Low | Effects are unlikely to be noticed even by individuals who know they are sensitive to air pollutants. |
| 4 - 6 | Moderate | Mild effects, unlikely to require action, may be noticed amongst sensitive individuals. |
| 7 - 9 | High | Significant effects may be noticed by sensitive individuals and action to avoid or reduce these effects may be needed (e.g. reducing exposure by spending less time in polluted areas outdoors). Asthmatics will find that their 'reliever' inhaler is likely to reverse the effects on the lung. |
| 10 | Very High | The effects on sensitive individuals described for 'High' levels of pollution may worsen. |
The forecast is produced for a number of different pollutants and their typical health effects are shown in the following table.
| Pollutant | Health Effects at High Level |
|---|---|
| Nitrogen dioxide Ozone Sulphur dioxide | These gases irritate the airways of the lungs, increasing the symptoms of those suffering from lung diseases. |
| Particulates | Fine particles can be carried deep into the lungs where they can cause inflammation and a worsening of heart and lung diseases |
Thu, 26 Aug 2010 14:54:12 GMT+00:00
takes a costly hit on 110-degree day istockAnalyst.com (press release) It pulls ozone away from the Valley floor and actually improves air quality . Air - quality readings for Wednesday won't be available until today. ... High heat and unhealthy air ; cooling on the way ABC30.com Extreme heat forces some schools to cancel practices ABC30.com
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to nearby residents Such findings might translate into new regulatory standards including discharge location mounting design and discharge height of restaurant ventilation systems Figure Legend The figure depicts modeled annual average PM 2 5 concentrations at the proposed Executive Park mixed use development project site attributable to vehicle traffic on US 101
Elena Craft
Fri, 13 Aug 2010 22:15:02 GM
Cruising iPhone apps (applications) one day, she stumbled upon more than one related to air pollution and . air quality. and wanted me to pass the information along to our Texas readers. One in particular, MyAirQuality, is a great, ...
