WHO challenges world to improve air quality
Manila , 5 October 2006―The World Health Organization (WHO) today issued a challenge to governments around the world to
improve air quality in their cities in order to protect people's health. The call comes as WHO unveils its new Air
Quality Guidelines with dramatically stricter standards for emission levels of pollutants. WHO believes that reducing
levels of one particular type of pollutant (known as PM10) could save as many as 300 000 lives every year. The
guidelines also substantially lower the recommended limits of ozone and sulphur dioxide.
The Air Quality Guidelines for the first time address all regions of the world and provide uniform targets for air
quality. These targets are far tougher than the national standards currently applied in many parts of the world – and in
some cities would mean reducing current pollution levels by more than three-fold.
Air pollution is estimated to cause approximately 2 million premature deaths worldwide per year. More than half of this
burden is borne by people in developing countries. In many cities, the average annual levels of PM10 (the main source of
which is the burning of fossil and other types of fuels) exceed 70 micrograms per cubic metre. The new guidelines say
that, to prevent ill health, those levels should be lower than 20 micrograms per cubic metre.
“By reducing particulate matter pollution from 70 to 20 micrograms per cubic metre as set out in the new guidelines, we
estimate that we can cut deaths from air pollution by around 15%," said Dr Maria Neira, WHO Director of Public Health
and the Environment. "By reducing air pollution levels, we can help countries to reduce the global burden of disease
from respiratory infections, heart disease, and lung cancer which they otherwise would be facing. Moreover, action to
reduce the direct impact of air pollution will also cut emissions of gases which contribute to climate and provide other
health benefits."
Given the increasing evidence of the health impact of air pollution, WHO revised its existing Air Quality Guidelines
(AQGs) for Europe and expanded them to produce the first guidelines which are applicable worldwide. These global
guidelines are based on the latest scientific evidence and set targets for air quality which would protect the large
majority of individuals from the effects of air pollution on health.
“These new guidelines have been established after a worldwide consultation with more than 80 leading scientists and are
based on review of thousands of recent studies from all regions of the world. As such, they present the most widely
agreed and up-to-date assessment of health effects of air pollution, recommending targets for air quality at which the
health risks are significantly reduced. We look forward to working with all countries to ensure these Guidelines become
part of national law,” says Dr. Roberto Bertollini, Director of the Special Programme for Health and Environment of
WHO's Regional Office for Europe.
Many countries around the world do not have regulations on air pollution, which makes the control of this important risk
factor for health virtually impossible. The national standards which do exist vary substantially, and do not ensure
sufficient protection for human health. While the World Health Organization accepts the need for governments to set
national standards according to their own particular circumstances, these guidelines indicate levels of pollution at
which the risk to health is minimal. As such, the new WHO guidelines provide the basis for all countries to build their
own air quality standards and policies supporting health with solid, scientific evidence.
Air pollution, in the form of particulate matter or sulfur dioxide, ozone or nitrogen dioxide, has a serious impact on
health. For example, in the European Union, the smallest particulate matter alone (PM2.5) causes an estimated loss of
statistical life expectancy of 8.6 months for the average European. While particulate matter is considered to be the
main air pollution risk factor for human health, the new Guidelines also recommend a lower daily limit for ozone,
reduced from 120 down to 100 micrograms per cubic metre. Achievement of such levels will be a challenge for many cities,
especially in developing countries, and particularly those with numerous sunny days when ozone concentrations reach the
highest levels, causing respiratory problems and asthma attacks.
For sulfur dioxide, the guideline level was reduced from 125 to 20 micrograms per cubic metre: experience has
demonstrated that relatively simple actions can rapidly lower sulfur dioxide levels and directly result in lower rates
of childhood death and disease. The guideline level for nitrogen dioxide remains unchanged; however, meeting these
limits, which are essential to prevent the health consequences of exposure such as bronchitis, remains a great challenge
in many areas where car traffic is intensive.
The guidelines propose progressive interim targets and provide milestones in achieving better air quality. “Building
upon the work carried out for several years on air pollution, WHO has now set new targets which Member States can refer
to in setting policy. The countries can measure their distance to these objectives, estimate the health impact of
current pollution levels and benefit from health gains by reducing them,” says Dr. Michal Krzyzanowski, Regional Adviser
for Air Quality, of the WHO Regional Office for Europe, coordinating the process of the Guidelines’ update from the WHO
office in Bonn.
The report, “WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide - summary of
risk assessment”, can be found on http://www.who.int/phe/health_topics/outdoorair_aqg
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