Halifax air quality map

Is there much interesting information about air pollution on the air quality map for Halifax?

The air pollution map for Halifax can be easily reached from the main city page. The map icon appears towards the top of this page and by selection will open a new page which is dedicated to air quality in and around the city.

The first thing a viewer will notice is the background colour of the map. This colour reflects the current air quality and is currently pale green which means the air quality is “Good”. The colours can range from pale green to dark maroon with the darker colours indicating worse air quality. These colours are standard throughout the entire IQAir website.

One more thing to note will be the number of coloured discs or circles that appear to be dotted across the map. These mark the positions of the ground-level air monitoring stations and all carry a number in the centre. This number is the United States Air Quality Index reading or US AQI for short. It is calculated by taking the measurements of six of the most commonly occurring pollutants which are usually both sizes of Particulate Matter (PM2.5 and PM10), ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. Once established, it is used as a standard when making comparisons between air quality in different cities across the world. The system is endorsed by the World Health Organisation (WHO). Each disc carries a wealth of information about air quality in that area of the city which can be accessed by selecting the disc of choice.

Briefly looking back at the main city page, it can be seen in the coloured banner at the top of the page that Halifax was enjoying a period of “Good” quality air in November 2022. The US AQI reading was just 12 and the main pollutant was PM2.5 with a recorded level of 3 µg/m³ which is within the target figure of 5 µg/m³ as recommended by the WHO.

Going back to the page showing the air pollution map for Halifax the number of stations and their operators can be seen immediately below the map. Currently, there are 5 stations supplied and operated by four contributors who all wish to remain anonymous.

Can areas of higher air pollution be seen on the air quality map for Halifax?

Areas of higher levels of pollution can be found by looking for the discs with the darkest colour and/or highest number. Alternatively, by scrolling further down the page just below the map can be seen a table which ranks the stations according to their levels of air pollution. Out of the five stations in Halifax, the one showing the highest levels of air pollution was at Johnston Building which displayed a US AQI reading of 22. Even though it displayed the highest reading, the air quality could still be classified as being “Good”.

Following that, the next table shows the stations’ popularity and ranks them according to the number of followers they each have. The current most popular station is also the same as the dirtiest; the Johnston Building.

Is there much more interesting information on the air pollution map for Halifax?

There is more valuable information on the air pollution map for Halifax but in order to see the entire content, the page needs to be viewed at maximum size. The icon to enable this can be found at the top right-hand side of the screen.

Once viewed this way, four options will be seen down the left-hand side of the screen. They can all be deactivated individually which will give the viewer a better idea of how each one affects the map.

The first option shows the location of the ground-level air monitoring stations which may not be directly over the city but still reveal a lot of interesting information about air pollution in that specific area. As already mentioned, each disc can be selected and opened to reveal this extra information.

The next option shows the location of any wildfires which might be burning in the vicinity. In November 2022, there were no reported fires burning in the vicinity. If any had been detected, then option four can add additional information because this option shows the speed and direction of the prevailing winds and can show where the ensuing smoke may drift to.

The third option can be very dramatic because it changes the background colour of the map to reflect the current air quality. The pale green colour seen now tells the viewer that the air quality is “Good”, however, if the colour of the map is too distracting, it can be disabled and the map will revert to a more subtle colour palette.

There is more information over on the right-hand side of the screen where a table will be found which ranks world cities according to their levels of air pollution. By default, only seven cities are shown but the page can be expanded to see the full ranking of all participating cities.

Can the source of the polluted air be seen on the air quality map for Halifax?

The source of the polluted air is not shown directly on the air pollution map for Halifax, however, the majority of these pollutants are released by human activity, including transportation, the use of fuels for electricity and heating, and various industrial activities. Indicators of sulphur oxides, nitrogen oxides, volatile organic compounds (VOC), carbon monoxide, ammonia, fine particles (PM2.5), and black carbon, a component of PM2.5, relate to emissions generated by human activity.

In 2020, the main sources of emissions of the six criteria air pollutants in Canada were from the oil and gas industry, transportation, agriculture, dust and fires (for example, road dust, dust from construction operations and prescribed fires).

Black carbon emissions come from combustion processes in the form of PM2.5. Black carbon is not emitted alone, it is part of PM2.5 with other components, such as organic carbon and inorganic compounds, such as sulphates. PM2.5 emitted by sources other than combustion, such as dust kicked up by vehicles on paved or unpaved roads or by wind and machinery in fields or surface mines, are not considered to be pollutants.