What is Ozone?
Ozone is an odourless, colourless gas at ambient concentrations and is one of the main components of smog.
What are the sources of ozone?
Ground-level ozone is not released straight into the atmosphere. It comes from photo-chemical reactions between nitrogen oxide (NOx) and volatile organic carbons in the presence of sunlight. From May to September, between noon and early evening are when high levels of ozone usually occur.
How does ozone affect people and the environment?
O3 causes irritation to the respiratory tract and to eyes. Contact with high levels of ozone can lead to chest tightness, coughing and wheezing. When exposed to ozone people that have respiratory or heart problems are at a higher risk. Ozone has been connected to increased hospital admissions and premature death. Ozone also has an impact on agriculture and crops.
What is Nitrogen Dioxide?
Nitrogen Dioxide is gas that is reddish-brown in colour and has a strong and irritating smell. In the air, nitrogen dioxide converts to form gaseous nitric acid and toxic organic nitrates. NO2 also plays a large part in atmospheric reactions that create ground level ozone, a main part in the makeup of smog. It is also a predecessor to nitrates which add to increased respirable particle levels in the atmosphere.
What are the sources of Nitrogen Dioxide?
All combustion in the air (ie car exhaust) creates oxides of nitrogen (Nox), of which NO2 is a major product. Natural sources of Nox include lightning and the aerobic activity of soil bacteria. However, these natural sources of emission are minor compared to those created by human activity.
How does Nitrogen Dioxide affect people and the environment?
Nitrogen dioxide can aggravate the lungs and reduce resistance to respiratory infection. For people with asthma and bronchitis an increase in sensitivity occurs. NO2 chemically changes into nitric acid and, when deposited contributes to lake acidification. Once chemically changed to nitric acid, nitrogen dioxide can corrode metals, fade fabrics, and degrade rubber. It can damage trees and crops, resulting in great losses.
What are suspended particles?
Suspended particles in the atmosphere are comprised of either solid particles or fine liquid droplets. Included in this group are: aerosols, smoke, fumes, dust, fly ash and pollen. The exact make up varies with both place and season. Particles in the atmosphere have been categorized based on size mostly because of the different health affect from particles of different diameters.
Particles with diameters of less than 100 microns (millionths of a metre) are classified as total suspended particles (TSP). In order to visualize how small a micron is, one micron is approximately the size of a single bacteria. Particles that are less than 10 microns and 2.5 microns are defined as inhalable particles (PM10) and respirable particles (PM2.5), respectively. The tinier the particle size, the further that particle will penetrate into the lungs.
What are the sources of suspended particles?
The bulk of the particle emissions from human activity can be categorized as TSP (total suspended particles).
Particles come from both natural and man made sources. Some of the natural sources include: windblown soil and mineral particles, volcanic ash, sea salt spray, and biological materials such as pollen, spores, bacteria and smoke from forest fires. The man-made sources result in both coarse and fine particles. Coarse particle matter comes from wind blown dust from agricultural soil, roads and construction sites. Smaller particles are created by the combustion of fossil fuel, residential heating and other sources as well. They can be released directly from a given source or formed in the atmosphere through the transformation of gaseous emissions. The composition of the particles varies with place, season, meteorology and daily weather.
How do suspended particles affect people and the environment?
The greatest effect on health comes from particles 10 microns or less in diameter PM10. Particles in this range can irritate bronchitis, asthma and other respiratory diseases. In some cases these small particles have been connected to greater hospital admissions and premature death. Those people that are most susceptible to the effects of particles include: those with asthma, cardiovascular or lung disease, as well as children and the elderly. Particles also cause corrosion, soiling damage to vegetation and visibility reduction.
What are Total Reduced Sulphur compounds?
Total Reduced Sulphur compounds create strong odours reminiscent of cabbage or rotten eggs.
What are the sources of TRS?
Industrial sources such as the steel industry, pulp and paper mills, refineries and sewage treatment facilities are all contributors. Natural sources of TRS include swamps, bogs and marshes.
What effect does TRS have on people and the environment?
Usually TRS compounds are not considered to be a health hazard. TRS compounds are one of the main causes of odours.
What is sulphur dioxide?
Sulphur dioxide is a colourless gas that smells like burnt matches. It can be oxidized to form sulphur trioxide. Which in the company of water vapour is easily changed to sulphuric acid mist. SO2 can be oxidized to form acid aeorsols. Sulphur dioxide is the predecessor to sulphates, which are one of the main components of respirable particles in the atmosphere.
What are the sources of sulphur dioxide?
Industrial sources of this gas include iron and steel mills, petroleum refineries and pulp and paper mills. Small sources include residential, commercial and industrial space heating.
What are the effects of Sulphur Dioxide on people and the environment?
Being exposed to high levels of SO2 can cause breathing problems, respiratory illness, changes in the lung's defences, and worsening respiratory and cardiovascular disease. People that are most sensitive to sulphur dioxide are those with asthma or chronic lung or heart disease. It also causes damage to trees and crops. Sulphur Dioxide, along with Nitrogen Oxides, are the precursors of acid rain. This adds to the acidification of lakes and streams, accelerated corrosion of buildings and a reduction in visibility. Sulphur Dioxide also leads to the formation of microscopic acid aerosols, which has a major impact on health as well as contributing to climate change.
What is Carbon Monoxide?
CO is a colourless, odourless and tasteless but poisonous gas produced primarily by incomplete burning of fossil fuels.
What are the sources of CO?
The transportation sector accounts for 65 per cent of all CO emissions from human activity in Ontario as seen in the table and diagram below. A large part of the remainder comes from primary metal producers (24 per cent) and from fuel combustion in space heating and industrial processes (6 per cent).
What are the effects of CO?
CO enters the blood stream and reduces oxygen delivery to the organs and tissues. People with heart disease are particularly sensitive. Exposure to high levels is linked with impairment of vision, work capacity, learning ability and performance of difficult tasks.
What are toxic air pollutants?
Toxic air pollutants, also known as hazardous air pollutants, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects. EPA is working with state, local, and tribal governments to reduce air toxics releases of 188 pollutants to the environment. Examples of toxic air pollutants include benzene, which is found in gasoline; perchlorethlyene, which is emitted from some dry cleaning facilities; and methylene chloride, which is used as a solvent and paint stripper by a number of industries. Examples of other listed air toxics include dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead compounds.
What are the health and environmental effects of toxic air pollutants?
People exposed to toxic air pollutants at sufficient concentrations and durations may have an increased chance of getting cancer or experiencing other serious health effects. These health effects can include damage to the immune system, as well as neurological, reproductive (e.g., reduced fertility), developmental, respiratory and other health problems. In addition to exposure from breathing air toxics, some toxic air pollutants such as mercury can deposit onto soils or surface waters, where they are taken up by plants and ingested by animals and are eventually magnified up through the food chain. Like humans, animals may experience health problems if exposed to sufficient quantities of air toxics over time.
Where do toxic air pollutants come from?
Most air toxics originate from human-made sources, including mobile sources (e.g., cars, trucks, buses) and stationary sources (e.g., factories, refineries, power plants), as well as indoor sources (e.g., some building materials and cleaning solvents). Some air toxics are also released from natural sources such as volcanic eruptions and forest fires.
How are people exposed to air toxics?
People are exposed to toxic air pollutants in many ways that can pose health risks, such as by:
Breathing contaminated air.
Eating contaminated food products, such as fish from contaminated waters; meat, milk, or eggs from animals that fed on contaminated plants; and fruits and vegetables grown in contaminated soil on which air toxics have been deposited.
Drinking water contaminated by toxic air pollutants.
Ingesting contaminated soil. Young children are especially vulnerable because they often ingest soil from their hands or from objects they place in their mouths.
Touching (making skin contact with) contaminated soil, dust, or water (for example, during recreational use of contaminated water bodies).
Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body tissues. Predators typically accumulate even greater pollutant concentrations than their contaminated prey. As a result, people and other animals at the top of the food chain who eat contaminated fish or meat are exposed to concentrations that are much higher than the concentrations in the water, air, or soil.
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