Pollutants Monitored

Hydrogen Sulphide (H₂S) is a colourless gas with a rotten egg odour. Its presence in natural gas makes the gas “sour.” Some sources include natural gas processing plants, petroleum refining, animal feedlots, and natural emissions from hot springs.

At low concentrations, H₂S can cause irritation of the eyes and the upper respiratory tract. Adults and children with asthma may be especially sensitive to low concentrations of hydrogen sulphide. At higher concentrations, hydrogen sulphide can be immediately life-threatening.

Methane (CH₄) is a colorless, odorless gas primarily emitted from natural gas systems, agriculture, and landfills. While not toxic at typical levels, it is a potent greenhouse gas and can displace oxygen in enclosed spaces. Its environmental impact contributes to climate change, indirectly affecting public health.

Nitrogen oxides (NO_x), mostly in the form of nitric oxide (NO) and nitrogen dioxide (NO₂), are produced by high temperature combustion of fossil fuels. Nitrogen oxide is the predominant pollutant emitted by combustion sources, but it is rapidly changed to nitrogen dioxide in the atmosphere. NO_x contributes to acid rain and plays a major role in atmospheric photochemical reactions and ground-level ozone formation and destruction. Oil and gas activities and transportation account for approximately 85% of the nitrogen emissions in Alberta; however, any combustion source will emit nitrogen dioxide (e.g., power plants, furnaces, space heaters). Some natural sources include volcanoes, lightning, biological decay, and oceans.

NO₂ has been linked to respiratory disease. Short-term exposure to NO₂ can cause airway inflammation. Individuals with pre-existing conditions such as asthma, chronic obstructive pulmonary disorder (COPD), and chronic bronchitis can be more sensitive to exposure.

Non-methane hydrocarbons (NMHCs) are a group of volatile organic compounds (excluding methane) released from vehicle exhaust, fuel evaporation, and industrial activities. They contribute to the formation of ground-level ozone and smog. Some NMHCs, like benzene and toluene, are toxic and may pose long-term health risks such as cancer or respiratory irritation.

Health effects from long-term or chronic exposure to petroleum hydrocarbons are known to cause decreased immune function, breathing problems, and kidney and liver damage.

Ground-level ozone is formed through photochemical reactions in the atmosphere. These reactions occur when sunlight acts on pollutants—primarily nitrogen oxides (NO_x) and volatile organic compounds (VOCs)—released by vehicles and industrial activities in urban areas. Ozone can be a major component of smog during the summer, especially in hot, sunny weather, and tends to be at lower levels in the winter. Ozone (O₃) can travel long distances and contribute to widespread regional air pollution episodes.

People most at risk from exposure to higher levels of O₃ include those with asthma, children, older adults, and those who are active outdoors, especially outdoor workers. Children are at greatest risk because their lungs are still developing. High levels of O₃ can cause the muscles in the airways to constrict, trapping air inside the tiny air sacs within the lungs (alveoli). This can lead to wheezing and shortness of breath, and can be serious in people with lung diseases such as asthma.

Ambient particulate matter consists of a mixture of particles of varying size and chemical composition. Particles that are less than 10 micrometers in diameter (PM₁₀) can include windblown soil, road dust, and particles from industrial activities. Fine particles, less than 2.5 micrometers in diameter (PM_2.5), can reduce visibility and contribute to soil acidification. PM_2.5 particles are formed from gases released to the atmosphere by combustion processes such as those from motor vehicles, power plants, gas processing plants, compressor stations, household heating, and forest fires. Particulate matter can also be comprised of biological material such as mold, bacteria, and pollen fragments.

Fine particles are small enough to enter the lungs and can be a human health concern. PM_2.5 has been linked to many health issues. Long-term exposure has been associated with increased lung and heart problems and even premature death.

Sulphur dioxide is generated both naturally and anthropogenically (human-made), including the processing and combustion of fossil fuels containing sulphur. It is a colourless gas with a pungent odour (like a lit match) and can be detected by taste and odour at concentrations as low as 300 ppb. Sulphur dioxide (SO₂) reacts in the atmosphere to form sulphuric acid and acidic aerosols, which contribute to acid rain. SO₂ combines with other atmospheric gases to produce fine particles, which may reduce visibility.

Brief exposure to high concentrations of sulphur dioxide and its products can produce human health effects, irritating the upper respiratory tract and aggravating existing cardiac and respiratory disease. Long-term exposure may increase the risk of developing chronic respiratory disease. People with asthma may have increased symptoms such as chest tightness and difficulty breathing.

Total hydrocarbons are divided into two broad categories: “non-reactive” and “reactive” hydrocarbons. The major non-reactive hydrocarbon in the atmosphere is methane, which is a naturally occurring colourless, odourless gas recognized as a major contributor to the greenhouse effect. Reactive hydrocarbons consist of many volatile organic compounds, some of which react with oxides of nitrogen in the atmosphere to form ozone. They generally occur at much lower concentrations than methane. Trees and plants are major natural emitters of reactive hydrocarbons, and large amounts of methane are produced naturally through the decay of vegetation and by agricultural feedlots. Other significant sources include motor vehicles, petroleum refineries, petrochemical plants, chemical solvents, and combustion from burning coal, gas, and wood.

Health effects from long-term or chronic exposure to petroleum hydrocarbons are known to cause decreased immune function, breathing problems, severe kidney, and liver damage.

Total reduced sulphur (TRS) includes hydrogen sulphide (H₂S), mercaptans, dimethyl sulphide, dimethyl disulphide and other sulphur compounds. Sources include fugitive emissions from petroleum refineries, tank farms for unrefined petroleum products, natural gas plants, petrochemical plants, oil sands facilities, sewage treatment facilities, pulp and paper operations that use the kraft pulp process, and animal feed lots. Natural sources include swamps, marshes, and bogs.

Health concerns related to exposure to TRS can include respiratory symptoms, decreased pulmonary function test results, and increases in pulmonary disease.

Meteorological parameters measured are wind speed and direction, temperature relative humidity, barometric pressure, and precipitation.