|4||Krasnaya Pahra, Moscow|
|8||Saint Petersburg, St.-Petersburg|
|优秀|| 50 美国 AQI||PM2.5|
|PM2.5|| 12 µg/m³|
|Open your windows to bring clean, fresh air indoors|
|Enjoy outdoor activities|
|星期五, 4月 9|
优秀 19 美国 AQI
|星期六, 4月 10|
优秀 29 美国 AQI
|星期日, 4月 11|
优秀 17 美国 AQI
|星期一, 4月 12|
优秀 40 美国 AQI
中等 53 美国 AQI
|星期三, 4月 14|
优秀 14 美国 AQI
|星期四, 4月 15|
优秀 8 美国 AQI
|星期五, 4月 16|
优秀 6 美国 AQI
|星期六, 4月 17|
优秀 6 美国 AQI
|星期日, 4月 18|
优秀 9 美国 AQI
Saint Petersburg is a city located in Russia, formerly known as Petrograd as well as Leningrad. It is the second largest city after the capital, Moscow, being home to some 5.4 million residents. It is also counted as the fourth most populated city in the whole of Europe. Saint Petersburg has a large amount of important recent history, having been the site that birthed the Russian empire as well as having other political and revolutionary movements take place within its limits.
In terms of economy, Saint Petersburg is a major trade and economic hub for Russia, with many different industries such as shipbuilding, military equipment manufacturing, production of pharmaceuticals and chemicals as well as a large variety of wholesale items for exportation and local use. With such a large economy based on the mass production and movement of materials, there would subsequently be pollution issues arising as a result.
Looking at the data taken over the course of 2019, Saint Petersburg (or St. Petersburg for short) came in with a PM2.5 reading of 7.6 μg/m³, placing it inside the World Health Organizations (WHO's) target bracket for the best air quality. This means that despite some pollutive issues, as a yearly average the city came in with a very respectable level of air quality, placing in 3561st place out of all cities ranked worldwide, as well as 9th place out of all cities registered thus far in Russia, making it the cleanest city in the country. So, whilst there are a few months with slightly elevated levels of pollution, overall St. Petersburg has a good quality of air.
Whilst there are many different sources of pollution contributing to overall levels of air pollution in Saint Petersburg, and indeed in many cities and countries across the globe, one of the most prominent factors in air pollution in St. Petersburg seems to be that of vehicular fumes and emissions.
With such a large amount of people living in the city, as well as the extended metropolitan and suburban areas, there is bound to be an enormous amount of traffic causing elevations in pollution levels. It is during periods of time such as rush hours that this would become more apparent, with hundreds of thousands of people making their way across town in their daily commute.
Although there does exist a good amount of public transport infrastructure, it does not seem to be enough to get people to permanently move away from their vehicles. As such, it is the main contributing cause, particularly when vehicles run on fuels such as diesel, putting out far more pollution that a greener alternative would. Other sources of pollution that would also contribute would be from factory and industrial areas, as well as fumes and exhausts from the many cargo ships coming in and out of the city’s ports. Construction sites can also drive up levels of fine particulate matter in the air, as well as releasing other dangerous materials such as heavy metals and microplastics.
Observing the data taken over 2019 as the best indicator as to what normal pollution levels are like (due to covid-19 largely shutting down mass movement across the world in 2020 and thus drastically reducing pollution levels), there is a mild pattern in the pollution readings taken.
Whilst the readings taken were fairly consistent in being within the WHO's target goal for great air quality, there were some slight elevations taken towards the end of the year and the beginning of the year, despite some data being missing at the start of 2019. Around October the pollution levels started to rise somewhat, with a very clean reading of 6.6 μg/m³ in October going up by almost double to 11.4 μg/m³ in November, and then with a reading of 8.1 μg/m³ in December.
These would most likely be correlating with the decrease in temperature, leading to a large scale increase in energy expenditure in both homes and businesses to keep them warm, as well as lower income districts and traditional homes resorting to the burning of materials such as wood for keeping warm. Of note is that extreme cold can trap pollution on the ground level, with thermal inversion taking place that causes a buildup of vehicular fumes and other pollutants to stay at ground level instead of moving into the upper atmosphere and dispersing.
These slightly elevated readings continued into the early months, with PM2.5 readings of 8 μg/m³ in March, and 10.8 μg/m³ in April. Only after May does the pollution level start to drop back down to its lower baseline. So, with November and April being the two months of the year to break out of the WHO's target and enter into the ‘good’ air quality ratings bracket (10 to 12 μg/m³ required), this would make them the most polluted months of the year, with November being the most polluted at 11.4 μg/m³.
Continuing on directly from the aforementioned higher months of pollution, as shown, the month of May is when pollution started to fall again, with a reading of 7.2 μg/m³ in May dropping down further to 6.3 μg/m³ in June, whereby the period of cleanest air quality was seen, with the months of June through to October being the best in their readings.
Air quality during this time was very respectable indeed, free from excessive amounts of contaminants or fine particulate matter in the air, although of note is that any PM2.5 reading above 0 does have a slight chance of causing adverse health effects, increasing of course as the number goes up. The cleanest month of the year was July, with a reading of 5.9 μg/m³, with all its surrounding months also having great air quality readings.
With much of the main pollution sources emanating from vehicles, there would be a subsequent link between the chemical compounds found in vehicle fumes also corresponding with the pollution in the air in St. Petersburg.
These would include ones such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), with nitrogen dioxide being the most prominent in its release from vehicles. Others would include black carbon and volatile organic compounds (VOC's), both of which are released from the incomplete combustion of fossil fuels as well as organic matter, and as such would see their release in engines that run on diesel fuels, as well as from factory emissions. Some examples of VOC's would include dangerous chemicals such as benzene, xylene, toluene and formaldehyde, all of which pose grave health risks and are exceptionally easy to respire, due to their volatile nature putting them in a gaseous state even at lower temperatures.