Sapporo air quality map

What information is available on the air pollution map for Sapporo?

As soon as the main city page for Sapporo is opened, the Sapporo air pollution map can be seen to the immediate left of the main titles. Once this is opened, the viewer will see the overall colour is greenish/yellow which is an indication of the overall air quality. This colour would indicate that the air quality is “Moderate”. The next thing to notice will be the number of coloured discs there are dotted around the area. These show the positions of the air monitoring stations. The various colours on them are explained in the legend at the foot of the page. Pale green represents “Good” air quality whilst the dark maroon colour shows the air as being “Hazardous”. There is also a number shown on the discs, this is the US AQI reading which is calculated by measuring the levels of up to six of the most commonly occurring air pollutants. It can then be used as a metric when comparing air quality in different cities across the globe. It is endorsed by the World Health Organisation (WHO). Sometimes the discs will almost be on top of each other but when the map is expanded, they will begin to separate and be seen more clearly. If a single disc is chosen, a new page will open which is dedicated to that specific area of the city.

In July 2022, there were three stations in and around Sapporo which are all operated by the government. This information is shown directly beneath the air quality map.

Briefly looking back at the main page, it was seen that in the third quarter of 2022, Sapporo was experiencing a period of “Moderate” quality air with a US AQI reading of 61. The levels of five pollutants were noted but the main one was PM2.5 which had a level of 17 µg/m³. This is almost three and a half times higher than the suggested level of 5 µg/m³ as recommended by the WHO.

Is there any other information available on the air quality map for Sapporo?

Once the air quality map for Sapporo is opened, it needs to be viewed in full-screen mode in order to see all the options available. Over on the left-hand side of the map can be seen four choices. The first one shows the location of the air monitoring stations in and around Sapporo and its environs. The map may need to be expanded further before the discs separate and become easier to see. The majority of the discs over the city are yellow, with the exception of two “Green” ones.

The second option would show the location of any fires which might be burning in the vicinity. Ideally, it should be studied alongside option four which shows the direction of the prevailing winds. This will help to see if the ensuing smoke will affect the city air quality or not.

The third option is possibly the most unexpected because it can change the entire colouration of the map. The overall colour is a reflection of the general state of the air over the area. Once it is deactivated, the colour of the map reverts to normal which some people may find easier to comprehend.

Over on the right-hand side of the screen can be seen a table which shows the ranking of world cities according to the cleanliness of their air. The most polluted cities are shown at the top of the table and the rest descend from there. Sometimes the inclusion of a city may come as a surprise as they are not usually considered to be a heavily polluted city.

Are the areas of higher pollution shown on the air pollution map for Sapporo?

The areas of higher air pollution can easily be identified by searching for the disc with the highest US AQI reading. This indicates an area of poor air quality. Alternatively, immediately below the map will be a list which shows the most polluted stations in descending order. The most polluted one carried the Japanese name of 国設札幌大気環境測定所 and displayed a US AQI reading of 86 which is “Moderate” air quality. This station happens to also be the most popular with over 2,000 followers. The remaining two stations are at Kita 1-jō and Sentā.

Is the source of the polluted air shown on the air quality map for Sapporo?

It is a known fact that some of the polluted air in Sapporo is blown in by prevailing winds from China. PM2.5 from China was recognised as a problem in Japan since it was announced in November 2010 that abnormal values of PM2.5 were observed in the Goto Islands and Tsushima in Nagasaki Prefecture. There are no big factories on these islands and no heavy traffic jams. For that reason, the problem of PM2.5 suddenly came to the attention when it became clear that the cause was yellow sand coming from China on a westerly wind.

Activities of various volcanoes in Japan have become active these days, and PM2.5 associated with the eruption also exists. Furthermore, although it is cleaner than in the past, the exhaust gas from the combustion of fossil fuels such as heavy oil is also a cause of PM2.5.

PM2.5 derived from automobiles cannot be ignored as there is a research paper that PM2.5 decreases by 7 per cent at a distance of 10 m from the main road.

PM2.5 always appears on the air quality map for Sapporo, but what is it?

PM2.5 is a very small particle with a diameter of 2.5 μm (1 μm (micrometre) = 1/1000 of 1 mm) or less floating in the atmosphere. PM is an acronym for "Particulate Matter" and is a cause of air pollution such as soot, dust, and sulphur oxides emitted from factories, automobiles, ships, and aircraft.

Since PM2.5 has a very small particle size, it easily penetrates deep into the lungs and is thought to increase the risk of respiratory and circulatory diseases such as asthma and bronchitis. In particular, people with respiratory and circulatory diseases, the elderly and children are considered to be susceptible, so caution is required.

The annual average concentration of PM2.5 in Japan is declining due to regulations on soot and smoke generation facilities such as factories and business establishments that we have been working on, and automobile emission regulations. However, PM2.5 concentration fluctuates depending on the season, and the concentration tends to increase from March to May every year. There are also differences depending on the region.