Air pollution is the fourth greatest overall risk factor for human health worldwide, after high blood pressure, dietary risks and smoking. Latest

estimates attribute 6.5 million premature deaths to air pollution. Among

the major air pollutants, fine particulate matter is the most damaging to

human health, and sulfur oxides, nitrogen oxides and ozone are associated

with a range of illnesses. In addition to human health, air pollution poses

risks to the environment, the economy and food security.

• Air pollutants arising from human activity overwhelmingly derive

from energy production and use, mainly the combustion of fossil fuels and

biomass. Three key pollutants are examined in detail in this report. Almost all

sulfur dioxide and nitrogen oxides emissions to the atmosphere are energyrelated, as are some 85% of emissions of particulate matter. Within the

energy sector, power generation and industry are the main sources of sulfur

dioxide, mostly from coal use. Oil use in vehicles and power generation are

the leading emitters of nitrogen oxides. Consumption of biomass, kerosene

and coal in the buildings sector, along with industrial use, are responsible

for the bulk of the particulate matter reaching the atmosphere.

• The concentration of people, economic activity and energy demand

in the world’s growing cities means that poor air quality is often regarded as

an urban problem. Yet poor air quality also affects many rural communities,

particularly where households continue to rely on solid biomass for cooking

and kerosene for lighting. Moreover, the major pollutants – including

secondary pollutants formed by chemical reactions in the atmosphere – can

be transported large distances from their sources.

• As the predominant source of air pollution, the energy sector

must be at the forefront of action to improve air quality around the world.

A range of proven policies and technologies are available to do so. In the

United States, European Union and Japan, regulations have helped to

achieve a major drop in emissions in some sectors, although challenges

remain. In developing Asia, less stringent regulations relating to fuel

quality, energy efficiency and post-combustion treatment technologies

generally mean that pollutant emissions have risen in line with very rapid

growth in energy demand seen in recent years, though improvements in

air quality are becoming an increasingly urgent policy priority in many

Asian countries. No jurisdiction can claim that the task of tackling air

pollution is complete

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