The Air We Breathe
- Clean dry air is a mixture of 4 main gasses:
- 78.08% is Nitrogen
- 20.95% is Oxygen
- 0.934 is Argon
- 0.035% is Carbon Dioxide
- Water vapour, Neon, Helium, Methane, Krypton, Hydrogen, Carbon Monoxide, Xenon, Ozone, Nitrogen Oxides, Sulfur Oxides and Hydrogen Sulfide are found in trace amounts
- An imbalance in the ratio of normal air gases causes polluted air
- An air pollutant is any substance which changes the physical or chemical properties of clean air and causes measurable effects on humans, animals, vegetation or materials.
- Air pollution can be caused by natural or anthropogenic effects (volcano eruptions vs burning fossil fuels)
- Air pollutants can be classified as either particulate or gaseous
Particulate Air Pollution
- Also known as aerosols
- The most visible of air pollutants
- These are small particles of solid matter and liquid drops suspended in the air.
- Mists, smoke, fumes and dust are all ways that these pollutants enter into the air
- Natural Sources Include: Forest Fires and Volcanic Eruptions
- Anthropogenic Sources include: coal and oil burning power plants, petroleum refineries, steel manufacturing and agricultural burning.
Effects of Aerosol Pollution
- Particulates first and foremost reduce visibility by creating smog
- Solid particulates interfere with a plants ability to absorb carbon dioxide by coating plant leaves
- Inhalation of particulates in humans and animals causes respiratory effects (lung disease, lung cancer, asthma, emphysema
- Influence weather patterns through cloud formation
Gaseous Air Pollution
- Carbon Monoxide, Nitrogen Oxides, Sulfur Oxides and Hydrocarbons are all examples of gaseous air pollution
- The enter the air through high temperature industrial processes and through engine combustion.
- These chemicals can act either as gasses or will dissolve in water.
Effects of Gaseous Pollution
- Carbon Monoxide and Nitrogen Oxides are both added to the air through the combustion of fossil fuels
- Both of these chemicals are extremely toxic to humans and animals
- If they are inhaled directly, they can be fetal
- Sulfur Oxides are added to the atmosphere through the burning of fossil fuels
- Sulfur Oxides react with water vapor to form acid precipitation
- If inhaled Sulfur Oxides cause respiratory tract illnesses
Air Quality Index
- The Air Quality Index (AQI) is an indicator of air quality, based on air pollutants that have adverse effects on human health and the environment
- The monitored pollutants are: ozone, fine particulate matter, nitrogen dioxide, carbon monoxide, sulphur dioxide and total reduced sulphur compounds
- To measure AQI the concentration of each pollutant, is measured hourly
- This is converted into a number ranging from zero upwards, using a common scale, or index.
- The calculated number for each pollutant is referred to as a sub-index.
- At a given site, the highest sub-index for any given hour becomes the AQI reading for that hour.
- The index is a relative scale, in that, the lower the index, the better the air quality.
- If the AQI reading is below 16, the air quality is in the very good category.
- If the AQI reading is in the range of 16 to 31, the air quality is in the good category.
- If the AQI reading is in the range of 32 to 49, the air quality is in the moderate category, and there may be some adverse effects for very sensitive people.
- If the AQI reading is in the range of 50 to 99, the air quality is in the poor category, and may have adverse effects for sensitive members of human and animal populations, and may cause significant damage to vegetation and property.
- If the AQI reading is above 99, the air quality is in the very poor category, and may have adverse effects for a large proportion of those exposed
Air Pollution Distribution
- Ontario’s air pollution is generally from the US Eastern seaboard
- Worldwide, air pollution is mainly noted in in and around industrialized areas,