According to WHO, 99% of the world’s population lives in areas where the air quality poses a threat to human health. At the same time, a recent United Nations study shows that many countries lack the necessary laws and regulations to combat air pollution. There are also significant differences in how countries monitor and measure air quality and present their data.
Global carbon dioxide emissions from fossil fuels and cement reached a record level of 36.6
billion tonnes in 2022. The consequence of this is that poor air quality continues to have a
highly negative impact on human health.
Laws are better than guidelines
In 2021, WHO published updated Global Air Quality Guidelines in which they state that
six pollutants are the most relevant to monitor:
|
Air Pollutant |
WHO recommended exposure levels |
|
Fine particulate matter (PM2.5) |
5μg/m3 annually or 15μg/m3 24-hour |
|
Coarse particulate matter (PM10) |
15μg/m3 annually or 45μg/m3 24-hour |
|
Ozone (O3) |
60μg/m3 annually or 100μg/m3 8-hour |
|
Nitrogen dioxide (NO2) |
10μg/m3 annually or 25μg/m3 24-hour |
|
Sulfur dioxide (SO2) |
40μg/m3 24-hour |
|
Carbon monoxide (CO) |
4 mg/m3 24-hour |
Recent scientific discoveries have put the threshold of air pollution levels considered harmful to
human health 50% lower today compared to eighteen years ago, when the previous
WHO Air Quality Guidelines were published.
There is, however, one fact that makes the WHO’s Global Air Quality Guidelines insufficient, and
it is not where the exposure thresholds are set - although it is of course very good that the levels
are adjusted according to new scientific findings. What makes the WHO guidelines insufficient is
that they are just that: guidelines and not laws.
No common legal framework
In a recent study, called The First Global Assessment of Air Pollution Legislation, the United Nations
presents an examination of air quality legislation in 194 countries and the European Union.
According to the study, one-third of all the countries in the world completely lack legally mandated
standards for outdoor air quality. It also concludes that there is no common international legal
framework for global Ambient Air Quality Standards (AAQS).
The national air quality laws often differ widely, with a whole variety of adopted metrics, standards
and obligations. One of the most significant disparities between countries is that they don’t use the
same scale when measuring AQI. It is also not possible to convert the data since every air quality
index is calculated in a different way. As an example, India, Singapore and the United States, all
use a scale from 0 to 500, but they have dissimilar ways of doing their calculations, making the
resulting values uncomparable.
In addition, the various countries don’t always give each pollutant the same value, which is often
due to political factors.
Of all the 194 countries in the UN study, only one third have transboundary laws in place to prevent
air pollution from travelling across borders into other countries. And no more than 7 percent have
laws regulating the quality of indoor air.
Variations in Air Quality Indexes
Examples of variations in Air Quality Indexes between some individual countries and the European Union:
|
Country |
Pollutants Considered |
AQI Scale |
Description |
|
United States: Air Quality Index |
TOTAL = 5 Ground-level Ozone (03) Particulate Matter (PM 2.5 & 10) Carbon monoxide (CO) Sulfur dioxide (SO2) Nitrogen dioxide (NO2) |
0-500 |
0-50 Good 51-10 Moderate 101-150Unhealthy for Sensitive Groups 201-300 Very Unhealthy 301-500 Hazardous |
|
Canada: Air Quality Health Index |
TOTAL = 3 Ground-level Ozone Particulate Matter (PM2.5/PM10) Nitrogen dioxide (NO2) |
0-10+ |
1-3 Low Risk 4-6 Moderate Health Risk 10+ Very High Health Risk |
|
United Kingdom: Daily Air Quality Index |
TOTAL = 5 Particulate matter (PM10) Fine particulate matter (PM2.5) Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) |
0-10 |
1-3 Low 4-6 Moderate 7-9 High 10 Very High |
|
European Union: The European AirQuality Index |
TOTAL = 5 Particulate matter (PM10) Fine particulate matter (PM2.5) Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) |
0-1250 |
0-100 Good 10-200 Fair 20-350 Moderate 25-500 Poor 50-750 Very poor 75-1250 Extremely poor |
|
Hong Kong: Air Quality Health Index |
TOTAL = 4 Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) Particulate Matter (PM2.5/PM10) |
0-10+ |
1-3 Low 4-6 Moderate 7 High 8-10 Very High 10+ Serious |
|
China: Air Quality Index |
TOTAL = 6 Sulfur dioxide (SO2) Nitrogen dioxide (NO2) Coarse Particulate Matter (PM10) Fine Particulate Matter (PM2.5) Carbon monoxide (CO) Ozone (O3) |
0-300+ |
0-50 Excellent 51-100 Good 101-150 Lightly Polluted 151-200 Moderately Polluted 201-300 Heavily Polluted 300+ Severely Polluted |
|
India: National Air Quality Index |
TOTAL = 8 Particulate Matter (PM10) Particulate Matter (PM2.5) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) Carbon monoxide (CO) Ozone (O3) Ammonia (NH3) Lead (Pb) |
0-500 |
0-50 Good 51-100 Satisfactory 101-200 Moderately polluted 201-300 Poor 301-400 Very poor 401-500 Severe |
|
Mexico: Metropolitan Index |
TOTAL = 5 Ozone (O3) Sulphur dioxide (SO2) Nitrogen dioxide (NO2) Carbon monoxide (CO) Particulate Matter (PM2.5/PM10) |
0-200+ |
0-50 Good 51-100 Acceptable 101-150 Bad 151-200 Very Bad 200+ Extremely Bad |
|
Singapore: Pollutants Standards Index |
TOTAL = 6 Sulphur dioxide (SO2) Particulate matter (PM10) Fine particulate matter (PM2.5) Nitrogen dioxide (NO2) Carbon monoxide (CO) Ozone (O3) |
0-251 |
0-55 Normal 56-150 Elevated 151-250 High 251- Very High |
Best protection indoors
We may have to wait for sufficient progress until most countries have air pollution laws and regulations
in place that are based on the latest scientific facts and fully enforced. However, in the meantime,
there are ways to protect ourselves. The simplest and most efficient protection against harmful airborne
particles is to have high-quality air filtration solutions in our buildings, especially since most of us spend
about 90% of our time indoors.
We recommend equipping your ventilation system with air filters like Camfil’s City range and investing
in one or several City range air purifiers to deal with the air pollution generated from inside your premises.
With the right filter solution, a significant portion of harmful particles can be stopped before they have
According to WHO, 99% of the world’s population lives in areas where the air quality poses a threat to human health. At the same time, a recent United Nations study shows that many countries lack the necessary laws and regulations to combat air pollution. There are also significant differences in how countries monitor and measure air quality and present their data.
Global carbon dioxide emissions from fossil fuels and cement reached a record level of 36.6
billion tonnes in 2022. The consequence of this is that poor air quality continues to have a
highly negative impact on human health.
Laws are better than guidelines
In 2021, WHO published updated Global Air Quality Guidelines in which they state that
six pollutants are the most relevant to monitor:
|
Air Pollutant |
WHO recommended exposure levels |
|
Fine particulate matter (PM2.5) |
5μg/m3 annually or 15μg/m3 24-hour |
|
Coarse particulate matter (PM10) |
15μg/m3 annually or 45μg/m3 24-hour |
|
Ozone (O3) |
60μg/m3 annually or 100μg/m3 8-hour |
|
Nitrogen dioxide (NO2) |
10μg/m3 annually or 25μg/m3 24-hour |
|
Sulfur dioxide (SO2) |
40μg/m3 24-hour |
|
Carbon monoxide (CO) |
4 mg/m3 24-hour |
Recent scientific discoveries have put the threshold of air pollution levels considered harmful to
human health 50% lower today compared to eighteen years ago, when the previous
WHO Air Quality Guidelines were published.
There is, however, one fact that makes the WHO’s Global Air Quality Guidelines insufficient, and
it is not where the exposure thresholds are set - although it is of course very good that the levels
are adjusted according to new scientific findings. What makes the WHO guidelines insufficient is
that they are just that: guidelines and not laws.
No common legal framework
In a recent study, called The First Global Assessment of Air Pollution Legislation, the United Nations
presents an examination of air quality legislation in 194 countries and the European Union.
According to the study, one-third of all the countries in the world completely lack legally mandated
standards for outdoor air quality. It also concludes that there is no common international legal
framework for global Ambient Air Quality Standards (AAQS).
The national air quality laws often differ widely, with a whole variety of adopted metrics, standards
and obligations. One of the most significant disparities between countries is that they don’t use the
same scale when measuring AQI. It is also not possible to convert the data since every air quality
index is calculated in a different way. As an example, India, Singapore and the United States, all
use a scale from 0 to 500, but they have dissimilar ways of doing their calculations, making the
resulting values uncomparable.
In addition, the various countries don’t always give each pollutant the same value, which is often
due to political factors.
Of all the 194 countries in the UN study, only one third have transboundary laws in place to prevent
air pollution from travelling across borders into other countries. And no more than 7 percent have
laws regulating the quality of indoor air.
Variations in Air Quality Indexes
Examples of variations in Air Quality Indexes between some individual countries and the European Union:
|
Country |
Pollutants Considered |
AQI Scale |
Description |
|
United States: Air Quality Index |
TOTAL = 5 Ground-level Ozone (O3) Particulate Matter (PM2.5 & PM10) Carbon monoxide (CO) Sulfur dioxide (SO2) Nitrogen dioxide (NO2) |
0-500 |
0-50 Good 51-10 Moderate 101-150 Unhealthy for Sensitive Groups 201-300 Very Unhealthy 301-500 Hazardous |
|
Canada: Air Quality Health Index |
TOTAL = 3 Ground-level Ozone Particulate Matter (PM2.5/PM10) Nitrogen dioxide (NO2) |
0-10+ |
1-3 Low Risk 4-6 Moderate Health Risk 10+ Very High Health Risk |
|
United Kingdom: Daily Air Quality Index |
TOTAL = 5 Particulate matter (PM10) Fine particulate matter (PM2.5) Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) |
0-10 |
1-3 Low 4-6 Moderate 7-9 High 10 Very High |
|
European Union: The European AirQuality Index |
TOTAL = 5 Particulate matter (PM10) Fine particulate matter (PM2.5) Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) |
0-1250 |
0-100 Good 10-200 Fair 20-350 Moderate 25-500 Poor 50-750 Very poor 75-1250 Extremely poor |
|
Hong Kong: Air Quality Health Index |
TOTAL = 4 Ozone (O3) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) Particulate Matter (PM2.5/PM10) |
0-10+ |
1-3 Low 4-6 Moderate 7 High 8-10 Very High 10+ Serious |
|
China: Air Quality Index |
TOTAL = 6 Sulfur dioxide (SO2) Nitrogen dioxide (NO2) Coarse Particulate Matter (PM10) Fine Particulate Matter (PM2.5) Carbon monoxide (CO) Ozone (O3) |
0-300+ |
0-50 Excellent 51-100 Good 101-150 Lightly Polluted 151-200 Moderately Polluted 201-300 Heavily Polluted 300+ Severely Polluted |
|
India: National Air Quality Index |
TOTAL = 8 Particulate Matter (PM10) Particulate Matter (PM2.5) Nitrogen dioxide (NO2) Sulphur dioxide (SO2) Carbon monoxide (CO) Ozone (O3) Ammonia (NH3) Lead (Pb) |
0-500 |
0-50 Good 51-100 Satisfactory 101-200 Moderately polluted 201-300 Poor 301-400 Very poor 401-500 Severe |
|
Mexico: Metropolitan Index |
TOTAL = 5 Ozone (O3) Sulphur dioxide (SO2) Nitrogen dioxide (NO2) Carbon monoxide (CO) Particulate Matter (PM2.5/PM10) |
0-200+ |
0-50 Good 51-100 Acceptable 101-150 Bad 151-200 Very Bad 200+ Extremely Bad |
|
Singapore: Pollutants Standards Index |
TOTAL = 6 Sulphur dioxide (SO2) Particulate matter (PM10) Fine particulate matter (PM2.5) Nitrogen dioxide (NO2) Carbon monoxide (CO) Ozone (O3) |
0-251 |
0-55 Normal 56-150 Elevated 151-250 High 251- Very High |
Best protection indoors
We may have to wait for sufficient progress until most countries have air pollution laws and regulations
in place that are based on the latest scientific facts and fully enforced. However, in the meantime,
there are ways to protect ourselves. The simplest and most efficient protection against harmful airborne
particles is to have high-quality air filtration solutions in our buildings, especially since most of us spend
about 90% of our time indoors.
We recommend equipping your ventilation system with air filters like Camfil’s City range and investing
in one or several City range air purifiers to deal with the air pollution generated from inside your premises.
With the right filter solution, a significant portion of harmful particles can be stopped before they have
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