Acid Deposition
A catch-all name for the settling out of acidic compounds onto various surfaces. It can include: 1) wet deposition by means of acid rain, fog, and snow; and 2) dry deposition of acidic particles (aerosols).
Acid Rain
Precipitation that is unusually acidic. It is harmful to plants, aquatic animals and infrastructure through the process of wet deposition. Acid rain is caused by emissions of compounds of ammonium, carbon, nitrogen, and sulphur which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970's to reduce the production of sulphuric oxides into the Earth's atmosphere with positive results.
Acute Exposure
One or a series of short-term exposures generally lasting for a short period of time (e.g. minutes or hours).
Acute Health Effect
A health effect that appears for a brief period of time and, in general, promptly after exposure.
Air Quality Monitoring
Click Passive or Continuous for an explanation.
Alberta Ambient Air Quality Guideline (AAAQG)
Concentration value adopted by the Province of Alberta with the intention of preventing deterioration of air quality. Guidelines for SO2, NO2, O3 and several other pollutants are based on the prevention of adverse human health and vegetation effects. Guidelines may be for one hour, 24 hours, or one year average concentrations.
Ambient Air Quality
The level of pollutants in the air around us. This is usually the concentrations of gases or particles people are exposed to, not the concentration of pollutants emitted by a specific source.
Ammonia (NH3)
is a colourless gas with the well known pungent odour found in household cleaners. NH3 is produced both by natural and human sources including the decay of plant material and animal waste. In Alberta, the fertilizer and commercial feedlots are the main industrial sources of NH3.
Made by or arising from man, not of natural origin.
See Air Quality Monitoring
A type of hydrocarbon, such as benzene or toluene. Some aromatics are toxic.
Average Annual Concentration
The sum of the one hour average concentration measurements for the year divided by the number of hours that measurements were made within that year. It can be compared against the Alberta Ambient Air Quality Guideline for the same period to assess absolute air quality, against data collected at other locations with similar characteristics (sources, population, etc.) for the same period for assessment purposes or against other years' data to assess improvement or degradation of air quality at the same location.
The monitoring of a living organism, plant or animal, to measure its health and document any visible symptoms of coincident air quality effects.
Carbon Dioxide (CO2)
A colorless, odorless gas that occurs naturally in the Earth's atmosphere. Significant quantities are also emitted into the air by fossil fuel combustion.
Carbon Monoxide (CO)
A colourless, odourless gas resulting from the incomplete combustion of hydrocarbon fuels. CO interferes with the blood's ability to carry oxygen to the body's tissues and results in numerous adverse health effects. Over 80% of the CO emitted in urban areas is contributed by motor vehicles.
Clean Air Strategic Alliance (website)
See Methane
Chronic Exposure
Long-term exposure, usually lasting for a relatively long period of time (e.g. months or years).
Chronic Health Effect
A health effect that occurs over a relatively long period of time (e.g. months or years).
See Carbon Monoxide
Data Warehouse
A repository of an organization's electronically stored data. Data warehouses are designed to facilitate reporting and analysis.
Fine Particulate Matter
See Particulate Matter
Global Warming
A controversial subject dealing with an increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Though the topic is controversial, global warming, whether natural or caused by human activity, is having significant effects on our environment. Reducing our impact will likely have some effect on its progress.
Global Warming Potential (GWP)
is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming.
Greenhouse Gases
Atmospheric gases such as carbon dioxide, methane, chlorofluorocarbons, nitrous oxide, ozone, and water vapour that slow the passage of re-radiated heat through the Earth's atmosphere.
See Hydrogen Sulphide
Compounds containing various combinations of hydrogen and carbon atoms. They may be emitted into the air by natural sources (e.g., trees) and as a result of fossil and vegetative fuel combustion, fuel volatilization, and solvent use. Hydrocarbons are a major contributor to smog. Hydrocarbons include aromatics and volatile organic compounds, many of which are toxic.
Hydrogen Sulphide (H2S)
A colorless, flammable, poisonous compound having a characteristic rotten-egg odour. About one third of the gas produced in Alberta contains H2S.
The atmospheric property of temperature increasing with height.
Methane (CH4)
A chemical compound that is the main component of natural gas. Methane is a relatively potent greenhouse gas with a high global warming potential. The abundance of methane in the Earth's atmosphere in 1998 was 1745 parts per billion, up from 700 ppb in 1750. Methane can trap about 20 times the heat of carbon dioxide. Global warming has the potential to trigger the release of large amounts of methane and cause Arctic methane release from permafrost.
Micron (mm)
One one-millionth of a meter (1X 106 m)
Mobile Sources
Sources of air pollution such as automobiles, motorcycles, trucks, off-road vehicles, boats, and airplanes.
Natural Sources
Non-manmade emission sources, including biological and geological sources, wildfires, and windblown dust.
See Ammonia
Nitric Oxide (NO)
Precursor of ozone, NO2, and nitrate; nitric oxide is usually emitted from combustion processes. Nitric oxide is converted to nitrogen dioxide (NO2) in the atmosphere, and then becomes involved in the photochemical processes and/or particulate formation.
Nitrogen Oxides (Oxides of Nitrogen, NOX)
A general term pertaining to compounds of nitric oxide (NO), nitrogen dioxide (NO2), and other oxides of nitrogen. Nitrogen oxides are typically created during combustion processes, and are major contributors to smog formation and acid deposition. NO2 at higher concentrations is associated with numerous adverse health effects.
See Non-Methane Hydrocarbon
See Nitrogen Oxides
Non-Methane Hydrocarbon (NMHC)
The sum of all hydrocarbon air pollutants except methane. NMHCs are significant precursors to ozone formation.
See Nitrogen Oxides
See Ozone
Ozone (O3)
A strong smelling, pale blue, reactive toxic chemical gas consisting of three oxygen atoms. It is a product of the photochemical process involving the sun's energy and ozone precursors, such as hydrocarbons and oxides of nitrogen. Ozone exists in the upper atmosphere ozone layer (stratospheric ozone) as well as at the Earth's surface in the troposphere (ozone). Ozone in the troposphere is associated with numerous adverse health effects. It is a major component of smog.
Particulate Matter (PM)
Any material, except pure water, that exists in the solid or liquid state in the atmosphere. The size of particulate matter can vary from coarse, wind-blown dust particles to fine particle combustion products.
An air pollutant consisting of small particles with an aerodynamic diameter less than or equal to a nominal 10 microns (about 1/7 the diameter of a single human hair). Their small size allows them to be inhaled but they do not reach the lungs.
Includes tiny particles with an aerodynamic diameter less than or equal to a nominal 2.5 microns. Their small size allows them to make their way to the air sacs deep within the lungs where they may be deposited and result in adverse health effects.
Parts per billion by volume or parts per million by volume
See Sulphur Dioxide
The layer of the Earth's atmosphere above the troposphere. It extends between 10 and 50 kilometers above the Earth's surface and contains the ozone layer in its lower portion. The stratospheric layer mixes relatively slowly; pollutants that enter it may remain for long periods of time.
Sulphur Dioxide (SO2)
A strong smelling, colorless gas that is formed by the combustion of fossil fuels. Sour gas processing plants, oil sands processing plants and coal-fired power generating plants are major sources of SO2. SO2 and other sulphur oxides contribute to the problem of acid deposition.
See Total Hydrocarbons
Total Hydrocarbons (THC)
The sum of all hydrocarbon air pollutants.
Total Organic Compounds (TOC)
Gaseous organic compounds, including reactive organic gases and the relatively unreactive organic gases such as methane.
Total Reduced Sulphur Compounds (TRS)
Sulphur-containing family of compounds consisting of hydrogen sulphide, mercaptans and others.
The boundary layer between the troposphere and the stratosphere characterized by its isothermal properties.
The lowest 10 kilometers to 20 kilometers of the Earth's atmosphere characterized by decreasing temperature with height.
See Total Reduced Sulphur Compounds
Urban Smog
Smog (smoke and fog) is a kind of air pollution. It develops from vehicular and industrial emissions that are acted on in the atmosphere by sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
Volatile Organic Compounds (VOCs)
Carbon-containing compounds that evaporate into the air (with a few exceptions). VOCs contribute to the formation of smog and/or may themselves be toxic. VOCs often have an odour, and some examples include gasoline, alcohol, and the solvents used in paints.
Zero Span
Indicates that the sensor was undergoing a routine calibration during the specified time.
Focus Design Group