At the present moment, I've been intensively working upon a comparative analysis of air pollution in various places in the world. J'adore voyager, so I've been wondering how's the air around the globe - and why. It is interesting to learn, why does the air quality vary from country to country, and what factors influence this variance.
I absolutely know that traffic is the major contributor to air pollution - this is what the evidence states. Nonetheless, higher mobility implies higher development, and higher development, in its turn, implies concern about health and environment. "Sustainability" and "concern" are two keywords for explaining the issue, no doubt. However, these two factors are latent, and there is no formula to describe them analytically. And they surely have a connection to the quality of the environment.
Not only there is no direct manner to explain why one nations inhale cleaner air than the others, but also there is no common measure for air quality! Various countries have various indices to report on air pollution, and, although there are similarities in the methodology of their construction, these indices are difficult to be narrowed down to one global measure and scale.
The disparity in methods aimed to keep track of air pollution in the world can be caused by the difference in concerns of the societies, as well as by governmental policies. Well-developed countries invest generously in research, and therefore they have their well-developed measures for air pollution, and they would probably not give up willingly on their findings and adopt some coefficient developed by another country. Less-developed countries simply have other issues to care about rather than creation of a global index to encompass and correctly reflect the whole air pollution in one scale. In a nutshell, the reasoning is comprehensible, but it is complicated to directly compare air pollution in the world.
A researcher might have an urge to do so - to analyse the cross-country environmental situation in context of competitiveness or just for some other reasons. "Normal people" might be curious about the condition of breathable air around the world as a factor to consider while changing the place of residence. No justification needed to explain, why is it desirable to be able to straightforwardly compare the air in different places.
It is a good thing that the concentrations of the criteria pollutants are recorded almost everywhere. This measurements are essential yet not sufficient. Those pollutants are tracked that are easier to monitor. Say, the concentrations of particles with the aerodynamic radius of 10 micrometers (PM10) are vastly reported, but the ultrafine matter (PM2.5 and smaller) is not so abundantly captured, because it is technically more complex. However, PM2.5 is a dangerous substance for human health, and its adverse effect is also connected to the ultra fine size of the particles, since they penetrate into tissues of the human body and may get into blood vessels.
Nitrogen dioxide (NO2), PM10 and CO2 concentrations can be mined for almost any country for almost any period of time, and this data is open source. Mean annual (quarterly, monthly) concentrations of any of the three can be used as a reference indicator to compare global air pollution, but, of course, they do not provide a sufficient informative coverage.
As for more sophisticated indicators currently used to depict air quality, quite a bunch of them can be named. The U.S. EPA reports on the Air Quality Index (AQI) - an indicator showing the threat that 5 criteria pollutants pose to public health. The range of the values is broad: 0 to 500. Canada has a similar measure named Air Quality Health Index (AQHI), which is calculated on the basis of the combined impact of three pollutants: groundlevel ozone (O3), particulate matter (PM10/ PM2.5) and nitrogen dioxide (NO2), and the range of its values is from 1 to 10+. In the UK, the use is made of an indicator called Daily Air Quality Index (DAQI), which on the daily basis keeps track of five major pollutants. Similarly to the Canadian index, this one provides values in the 1 to 10 range. In China, the quality of air is reflected by a measure called Air Pollution Index (API), same in Hong Kong. The Chinese API is evaluated by the country's Ministry of Environmental Protection and its values are between 0 and 300+. In Hong Kong, the API index is provided by the HK's Environmental Protection Department. It is calculated on the basis of 5 pollutants and has a scale of 0 to 500, similarly to the U.S. AQI range of values. In Malaysia, the abbreviation "API" is used, too, but it stands for "Air Pollutant Index", and its values range from 0 to 300+. Finally, in Russia a general air quality measure is called Atmosphere Pollution Index (ИЗА, Индекс Загрязнения Атмосферы). It is a complex measure, as well, reflecting cumulative impact of several contaminative substances, and it ranges from 0 to 14+.
The indicators listed above have much in common: all of them are based on the values of one to five criteria pollutants. Once the desired sensitivity (scale) is established, it is feasible to come up with a synthetic criteria that would be common for all countries.
By now, unfortunately, no such measure is known.
I absolutely know that traffic is the major contributor to air pollution - this is what the evidence states. Nonetheless, higher mobility implies higher development, and higher development, in its turn, implies concern about health and environment. "Sustainability" and "concern" are two keywords for explaining the issue, no doubt. However, these two factors are latent, and there is no formula to describe them analytically. And they surely have a connection to the quality of the environment.
Not only there is no direct manner to explain why one nations inhale cleaner air than the others, but also there is no common measure for air quality! Various countries have various indices to report on air pollution, and, although there are similarities in the methodology of their construction, these indices are difficult to be narrowed down to one global measure and scale.
The disparity in methods aimed to keep track of air pollution in the world can be caused by the difference in concerns of the societies, as well as by governmental policies. Well-developed countries invest generously in research, and therefore they have their well-developed measures for air pollution, and they would probably not give up willingly on their findings and adopt some coefficient developed by another country. Less-developed countries simply have other issues to care about rather than creation of a global index to encompass and correctly reflect the whole air pollution in one scale. In a nutshell, the reasoning is comprehensible, but it is complicated to directly compare air pollution in the world.
A researcher might have an urge to do so - to analyse the cross-country environmental situation in context of competitiveness or just for some other reasons. "Normal people" might be curious about the condition of breathable air around the world as a factor to consider while changing the place of residence. No justification needed to explain, why is it desirable to be able to straightforwardly compare the air in different places.
It is a good thing that the concentrations of the criteria pollutants are recorded almost everywhere. This measurements are essential yet not sufficient. Those pollutants are tracked that are easier to monitor. Say, the concentrations of particles with the aerodynamic radius of 10 micrometers (PM10) are vastly reported, but the ultrafine matter (PM2.5 and smaller) is not so abundantly captured, because it is technically more complex. However, PM2.5 is a dangerous substance for human health, and its adverse effect is also connected to the ultra fine size of the particles, since they penetrate into tissues of the human body and may get into blood vessels.
Nitrogen dioxide (NO2), PM10 and CO2 concentrations can be mined for almost any country for almost any period of time, and this data is open source. Mean annual (quarterly, monthly) concentrations of any of the three can be used as a reference indicator to compare global air pollution, but, of course, they do not provide a sufficient informative coverage.
As for more sophisticated indicators currently used to depict air quality, quite a bunch of them can be named. The U.S. EPA reports on the Air Quality Index (AQI) - an indicator showing the threat that 5 criteria pollutants pose to public health. The range of the values is broad: 0 to 500. Canada has a similar measure named Air Quality Health Index (AQHI), which is calculated on the basis of the combined impact of three pollutants: groundlevel ozone (O3), particulate matter (PM10/ PM2.5) and nitrogen dioxide (NO2), and the range of its values is from 1 to 10+. In the UK, the use is made of an indicator called Daily Air Quality Index (DAQI), which on the daily basis keeps track of five major pollutants. Similarly to the Canadian index, this one provides values in the 1 to 10 range. In China, the quality of air is reflected by a measure called Air Pollution Index (API), same in Hong Kong. The Chinese API is evaluated by the country's Ministry of Environmental Protection and its values are between 0 and 300+. In Hong Kong, the API index is provided by the HK's Environmental Protection Department. It is calculated on the basis of 5 pollutants and has a scale of 0 to 500, similarly to the U.S. AQI range of values. In Malaysia, the abbreviation "API" is used, too, but it stands for "Air Pollutant Index", and its values range from 0 to 300+. Finally, in Russia a general air quality measure is called Atmosphere Pollution Index (ИЗА, Индекс Загрязнения Атмосферы). It is a complex measure, as well, reflecting cumulative impact of several contaminative substances, and it ranges from 0 to 14+.
The indicators listed above have much in common: all of them are based on the values of one to five criteria pollutants. Once the desired sensitivity (scale) is established, it is feasible to come up with a synthetic criteria that would be common for all countries.
By now, unfortunately, no such measure is known.
