1 people follow this city
|1||118 Risebrough Circuit|
|1||118 Risebrough Circuit|
Get an AirVisual Outdoor and contribute to collecting millions of data points for the Markham map to track local air pollution
The air pollution map for Markham is very easy to find on the main city page. At the top of this page is a map icon which when selected will open another page which is dedicated to air quality in and around the city.
Once the map is open, the first thing a viewer will notice is the background colour of the map which reflects the current air quality. In October 2022, it was green in colour which represents “Good” air quality. The viewer will also notice several coloured circles dotted across the page. These show the location of the ground-level air monitoring stations. If an area is of special importance, clicking on the disc will prompt another page to open with more details about that specific area of the city.
These discs carry the same set of colours as the map does so they each indicate the quality of air found in that location. They also display a number which is the United States Air Quality Index number or US AQI for short. This figure is calculated by measuring six of the most commonly found pollutants in city air. They usually include Particulate Matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. Once calculated the number is then used as a metric when comparing air quality in other locations across the globe. It is both encouraged and endorsed by the World Health Organisation (WHO).
Looking back at the main city page, the US AQI number is prominently displayed at the top of the page inside a coloured banner. Together it makes it easy to see the cleanliness of the air at a glance. The main pollutant measured was PM2.5 with a recorded level of 2.8 µg/m³ which falls nicely below the target figure of 5 µg/m³ as recommended by the WHO.
Immediately below the air pollution map for Markham is shown the number of ground-level air monitoring stations there are that provide all the necessary data. Currently, there is just one station which does this and it is supplied and operated by an entity that wished to remain anonymous.
There is more information on this page, but in order to access all of it, the page needs to be viewed in full-screen mode, otherwise, some tables and charts could remain obscured.
On the far left-hand side of the screen will be a drop-down box showing four options. All of these can be turned on or off as required in order to make it clearer what each choice does.
The first choice shows the location of the ground-level air monitoring stations both in Markham and also the immediate vicinity. They use the same colours as the rest of the IQAir site, the meaning of which is explained in the legend at the foot of the page. If some of the discs appear to overlap, slightly enlarging the map will allow them to separate.
The second option shows the position of any wildfires that might be burning in the area. Towards the end of 2022, there was one fire burning around Burlington but it seems to be a safe distance away from Markham. By checking option four which shows the wind speed and direction, the viewer will get a good idea as to where the smoke from the fire will blow.
Option three can be very dramatic as it changes the background colour of the map to reflect the current state of the air. Some viewers may find this complete saturation of colour to be a little overwhelming, in which case, deactivating the option will make the map revert to a more standard set of colours which could be easier to understand.
There is more information on the right-hand side of the screen. Here is a table which ranks world cities according to their levels of air pollution. By default, only seven are shown but more information about the rest of the world cities is available by selecting the box which is shown on the screen.
More information about the stations can be seen beneath the map. It lists the most polluted station and also the station with the most followers. This is perhaps not very significant when there is only one station!
The source of the air pollution is not directly shown on the air pollution map for Markham, however, a large number of pollutants are emitted near road infrastructures, and come not only from vehicle tailpipe emissions but also from other sources such as tyre and brake wear, vehicle air conditioning technologies, wear of roads and maintenance of their surroundings (use of phytosanitary products, etc.). To these so-called "primary" pollutants because emitted directly by pollution sources, are added so-called "secondary" pollutants, such as particles, resulting from chemical reactions between pollutants occurring in the atmosphere.
In a report, the WHO indicates that residential heating with wood or coal is a significant source of air pollution both outside and inside buildings (except in the case of efficient heating appliances in terms of reducing polluting emissions).
According to the WHO, particles from wood combustion are associated with an exacerbation of respiratory pathologies, in particular asthma and chronic obstructive pulmonary disease (COPD), bronchitis and otitis media. According to the literature, there is no reason to consider the particles resulting from the combustion of biomass as less harmful to health than those from other sources of urban pollution, but there are however few studies on the effects cardiovascular effects of these particles. On the other hand, there is evidence linking wood burning to certain respiratory symptoms.
Particles in suspension include microscopic matter in suspension in the air or in water. Particles suspended in the air are called aerosols. PM10 includes particles with a diameter of less than 10 microns, PM2.5 those less than 2.5 microns.
The toxicity of suspended particles is essentially due to particles with a diameter of less than 10 microns. They can be emitted directly into the air by anthropogenic activities (industry, residential, agriculture, transport) and by natural sources (forest fires, volcanic eruptions, etc.). Particles can also form directly in the atmosphere by physico-chemical reactions between pollutants already present in the atmosphere.
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