An air quality measurement station in Edinburgh, Scotland

The Air Quality Index (AQI) is a standardized indicator of the air quality in a given location. Pollution is the introduction of contaminants into an environment that causes instability disorder harm or discomfort to the physical systems or living organisms they are in Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort Acid rain is Rain or any other form of precipitation that is unusually Acidic It has harmful effects on plants aquatic animals and infastructure Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. The haloalkanes (also known as halogenoalkanes or alkyl halides) are a group of Chemical compounds consisting of Alkanes such as Methane Global dimming is the gradual reduction in the amount of global direct Irradiance at the Earth 's surface that was observed for several decades after the start of systematic Global warming is the increase in the average measured temperature of the Haze is traditionally an atmospheric phenomenon where dust smoke and other dry particles obscure the clarity of the sky Indoor Air Quality (IAQ deals with the content of interior air that could affect health and comfort of building occupants Ozone depletion describes two distinct but related observations a slow steady decline of about 4 percent per decade in the total amount of Ozone in Earth's Particulates, alternatively referred to as particulate matter (PM or fine particles, are tiny particles of solid or liquid suspended in a gas Smog is a kind of Air pollution; the word "smog" is a Portmanteau of Smoke and Fog. Water pollution is the contamination of Water bodies such as Lakes Rivers Oceans and Groundwater caused by human activities Eutrophication is an increase in chemical Nutrients -- typically compounds containing Nitrogen or Phosphorus -- in an Ecosystem, and may occur For other uses of the term "hypoxia" see Hypoxia. Hypoxia or oxygen depletion is a phenomenon that occurs in aquatic environments Marine pollution is the harmful effect caused by the entry into the ocean of chemicals particles, or Plastic debris. For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into Ship pollution is the pollution of air and Water by Shipping. Surface runoff is a term used to describe when soil is infiltrated to full capacity and excess Water, from Rain, Snowmelt, or other sources flows Thermal pollution is a Temperature change in natural bodies of water caused by human influence Distinguish from Wastwater (a lake in the Lake District in northwest England Waterborne diseases are caused by Pathogenic Microorganisms which are directly transmitted when contaminated Drinking water is consumed Water quality is the physical chemical and biological characteristics of Water in relationship to a set of standards Water stagnation occurs when Water stops flowing Stagnant water can be a major Environmental hazard. Soil contamination is caused by the presence of man-made chemicals or other alteration in the natural soil environment Bioremediation can be defined as any process that uses Microorganisms Fungi, green plants or their Enzymes to return the natural environment altered A herbicide is used to kill unwanted Plants Selective herbicides kill specific targets while leaving the desired Crop relatively unharmed A pesticide is a substance or mixture of substances used to kill a pest. Radioactive contamination is the uncontrolled distribution of radioactive material in a given environment Actinides in the environment refer to the sources environmental behaviour and effects of Actinides in the environment. Environmental Radioactivity is the study of radioactive materials in the Human environment. Fission products are the atomic fragments left after a large nucleus fissions. Fallout is the residual radiation hazard from a Nuclear explosion, so named because it "falls out" of the atmosphere into which it is spread during the explosion Plutonium in the environment is an article which is part of the Actinides in the environment series Radiation poisoning, also called " radiation sickness " or a " creeping dose " is a form of damage to organ tissue due to excessive exposure to This is a subpage of Environmental radioactivity. Radium Radium in quack medicine See the story of Eben Byers for details of one very nasty case Uranium in the environment, this page is about the Science of Uranium in the environment and in animals (including humans Introduced species|Weed Invasive species is a phrase with several definitions Light pollution, also known as photopollution or luminous pollution, is excess or obtrusive Light created mainly by Humans Among other effects Noise pollution (or environmental noise) is displeasing human- or machine-created sound that disrupts the activity or balance of human or animal life Radio spectrum pollution is the straying of waves in the radio and Electromagnetic spectrums outside their allocations that cause problems for some activities Visual pollution is the term given to unattractive or unnatural (human-made visual elements of a vista a Landscape, or any other thing that a person might not want to For other similarly-named agreements see Montreal Convention (disambiguation. Protocol to the 1979 Convention on Long-Range Transboundary Air Pollution Concerning the Control of Emissions of Nitrogen Oxides or Their Transboundary Fluxes, opened for signature on The Kyoto Protocol is a protocol to the international Framework Convention on Climate Change with the objective of reducing Greenhouse gases in an effort The Convention on Long-Range Transboundary Air Pollution, often abbreviated as Air Pollution or CLRTAP, is intended to protect the human environment against Air This is a list of environmental organizations. See also Environmental organization Intergovernmental organizations International organizations The Department for Environment Food and Rural Affairs ( Defra) is the United Kingdom government department responsible for environmental protection The Global Atmosphere Watch (GAW is a worldwide system established by the World Meteorological Organization a United Nations agency to monitor trends in the Greenpeace, originally known as the Greenpeace Foundation, was founded in Vancouver, British Columbia, Canada in 1972 The National Ambient Air Quality Standards (NAAQS are standards established by the United States Environmental Protection Agency that apply for outdoor Air Environmental science is the study of interactions among physical chemical and biological components of the environment. See also Nature The natural environment, commonly referred to simply as the environment, is a terminology that is comprised of all living and Edinburgh ( ˈɛdɪnb(ərə Dùn Èideann) is the Capital of Scotland and is its second largest city after Glasgow. Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Standardization (or standardisation) is the process of developing and agreeing upon technical standards. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five In the vernacular quality can mean a high degree of excellence (“a quality product” a degree of excellence or the lack of it (“work of average quality” or a property of It measures mainly ground-level ozone and particulates (except the pollen count), but may also include sulfur dioxide, and nitrogen dioxide. Ozone (O3 is a key constituent of the Troposphere (it is also an important constituent of certain regions of the Stratosphere Particulates, alternatively referred to as particulate matter (PM or fine particles, are tiny particles of solid or liquid suspended in a gas Pollen count is the measurement of the number of grains of Pollen in a Cubic meter of Air. Nitrogen dioxide is the Chemical compound with the formula N[[Oxygen O]]2 Various agencies around the world measure such indices, though definitions may change between places.

The United States Environmental Protection Agency (EPA) and the Meteorological Service of Canada (MSC) differ on what AQI structure and health classification is used:

Health classifications used by the EPA:

•   0-50  Good is usually green
•  51-100 Moderate is usually yellow
• 101-150 Unhealthy for sensitive groups is usually orange
• 151-200 Unhealthy is usually red
• 201-300 Very unhealthy is usually purple
• 301-500 Hazardous is usually maroon

The EPA's AQI 100 corresponds to 0. The Meteorological Service of Canada (MSC is a division of Environment Canada, which primarily provides public meteorological information and Weather forecasts 08 ppm ozone, and to other levels for other pollutants. Source: EPA

The AQI standards in Canada are relatively more stringent. The current health classifications used by the Meteorological Service of Canada (MSC) are as follows:

• 0-25*: Good (green)
• 26*-50: Fair (yellow)
• 51-100: Poor (orange)
• 101+: Very poor (red)

In Ontario, 31 is the upper limit for good and 32 the lower limit for moderate. The Meteorological Service of Canada (MSC is a division of Environment Canada, which primarily provides public meteorological information and Weather forecasts Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec Zero to 15 is classified as very good, and is given the color blue.

In June 2007, the EPA proposed a slight possible tightening of the pollution standards associated with smog after an independent EPA scientific board said that the standard “needs to be substantially reduced” and that there is “no scientific justification” for retaining the current, weaker standard. ^[1]

In light of the new scientific findings, one should expect adjustments in the AQI such that pollution currently denoted as "moderate" will in the future be recognized as "unhealthy. "

The AQI can worsen (go up) due to lack of dilution with fresh air. Stagnant air, often caused by an anticyclone or temperature inversion, or other lack of winds lets air pollution remain in a local area. In Meteorology, an anticyclone (that is opposite to a Cyclone) is a Weather phenomenon in which there is a descending movement of the air and In meteorology an inversion is a deviation from the normal change of an atmospheric property with altitude Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort On these days, the news media may ask the public to carpool or use public transport, or take other air pollution prevention measures such as teleworking. The news media refers to the section of the Mass media that focuses on presenting current News to the public Public is of or pertaining to the people relating to or affecting a nation state or community opposed to private; as the public treasury a road or lake Carpooling (also known as car-sharing, ride-sharing, lift-sharing) is the shared use of a car by the driver and one or more passengers usually Telecommuting, e-commuting, e-work, telework, working at home (WAH, or working from home (WFH is a work arrangement in

Other Indices

Hong Kong

Main article: Air Pollution Index

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. The Air Pollution Index (API is a simple and generalized way to describe the air quality in Mainland China, Hong Kong and Malaysia.

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.

Malaysia

Main article: Air Pollution Index

The air quality in Malaysia is reported as the API or Air Pollution Index. The Air Pollution Index (API is a simple and generalized way to describe the air quality in Mainland China, Hong Kong and Malaysia. For the biogeographical region see Malesia Malaysia (məˈleɪʒə or /məˈleɪziə/ is a country that consists of thirteen states and Four of the index's pollutant components (i. e. , carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide) are reported in ppmv but PM₁₀ particulate matter is reported in μg/m³. "Parts-per" notation is used especially in Science and Engineering, to denote Ratios (relative proportions in measured quantities particularly Particulates, alternatively referred to as particulate matter (PM or fine particles, are tiny particles of solid or liquid suspended in a gas

Unlike the American AQI, the index number can exceed 500. Above 500, a state of emergency is declared in the reporting area. A state of emergency is a governmental declaration that may suspend certain normal functions of government alert citizens to alter their normal behaviors or order government agencies Usually, this means that non-essential government services are suspended, and all ports in the affected area closed. There may also be a prohibition on private sector commercial and industrial activities in the reporting area excluding the food sector.

For more information on the API reading please go here http://www.doe.gov.my/index.php?option=com_content&task=view&id=188&Itemid=370&lang=en

Singapore

Singapore uses the Pollutant Standards Index to report on its air quality. Singapore The Pollutant Standards Index, or PSI, provides a uniform system of measuring pollution levels for the major air pollutants [1]

United Kingdom

The Met Office of the United Kingdom (UK) issues air quality forecasts 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). For the UKMET model see Tropical cyclone forecast model. The Met Office (originally an abbreviation for Meteorological Office, The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located These levels are based on the health effects of each pollutant.

The forecast is produced for a number of different pollutants and their typical health effects are shown in the following table.

United States

The United States Environment Protection Agency (USEPA) developed the Pollutant Standards Index (PSI) to provide accurate, timely and easily understandable information about daily levels of air pollution. The Pollutant Standards Index, or PSI, provides a uniform system of measuring pollution levels for the major air pollutants

It is no longer in use, having been replaced by the AQI, which is more sensitive. For example, particulate matter with an aerodynamic diameter less than 2. 5 micrometres (PM2. A micrometre ( American spelling: micrometer; symbol µm) is one millionth of a Metre, or equivalently one thousandth of a Millimetre 5) is a sub index, replacing the less sensitive PM10 component of the PSI.

Notes

In the context of this article about air quality:

• ppmv = parts per million by volume = volume of pollutant gas per million volumes of ambient air
• PM₁₀ = particulate matter smaller than 10 μm in diameter
• μg/m³ = micrograms per cubic metre of ambient air
• μm = micrometre

The air quality in the United States has improved dramatically over 23 years.

Air quality by country or region

• British Columbia
• Hong Kong

See also

• Air pollution
• Air Pollution Index
• Atmospheric dispersion modeling
• Emission standard
• European emission standards
• Haze
• Indoor air quality
• National Ambient Air Quality Standards - U. Air pollution is a concern in British Columbia (BC Canada because of its effects on Health and visibility Air pollution in Hong Kong is considered a serious problem It affects flora and fauna in the area and the health of residents living there Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort The Air Pollution Index (API is a simple and generalized way to describe the air quality in Mainland China, Hong Kong and Malaysia. Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. Emission standards are requirements that set specific limits to the amount of Pollutants that can be released into the environment European emission standards define the acceptable limits for exhaust emissions of new vehicles sold in EU member states Haze is traditionally an atmospheric phenomenon where dust smoke and other dry particles obscure the clarity of the sky Indoor Air Quality (IAQ deals with the content of interior air that could affect health and comfort of building occupants The National Ambient Air Quality Standards (NAAQS are standards established by the United States Environmental Protection Agency that apply for outdoor Air S. standards for EPA intervention
• Pollutant Standards Index
• Smog

References

External links

• AQI at airnow.gov - cross-agency U. The Pollutant Standards Index, or PSI, provides a uniform system of measuring pollution levels for the major air pollutants Smog is a kind of Air pollution; the word "smog" is a Portmanteau of Smoke and Fog. S. Government site
• New Mexico Air Quality and API data - Example of how New Mexico Environment Department publishes their Air Quality and API data.
• AQI at Meteorological Service of Canada
• The pollution index of the UK Met Office
• API at JAS (Malaysian Department of Environment)
• API at Hong Kong - Environmental Protection Department of the Government of the Hong Kong Special Administrative Region
• San Francisco Bay Area Spare-the-Air - AQI explanation
• Malaysia Air Pollution Index