The World Health Organization (WHO) on Thursday urged governments around the world to improve air quality in cities in order to protect people's health.

Air pollution is estimated to cause 2 million premature deaths worldwide per year, and more than half of this burden is borne by people in developing countries, the UN health agency said as it unveiled its new Air Quality Guidelines.

The new 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 quarters, the WHO said.

The WHO said it believes that reducing levels of one particular type of pollutant, known as PM10, could reduce deaths in polluted cities by as much as 15 percent every year.

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 pur cubic meter.

The new guidelines say that, to prevent ill health, those levels should be lower than 20 micrograms, the WHO said.

The new guidelines also substantially lower the level of recommended permissible limits of ozone and sulfur dioxide.

"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," said Dr. Maria Neira, head of the WHO's public health and environment division.

"Moreover, action to reduce the direct impact of air pollution will also cut emissions of gases which contribute to climate change and provide other health benefits," she said.

Many countries lack regulations on air pollution, making control of this important risk factor for health virtually impossible, according to the WHO.

"The national standards which do exist vary substantially, and do not ensure sufficient protection for human health," it said.

The agency said that it accepted the need for governments to set national standards according to their own particular circumstances, but noted that the new guidelines indicate levels of pollution at which the risk to health is minimal.

Source: Xinhua