As many as one billion people, mostly women and children, are regularly
exposed to levels of indoor air pollution exceeding WHO guidelines by up to 100 times.
This startling statistic was quoted at a WHO strategy meeting on Air Quality and Health
held in Geneva this week.
Air pollution is a major environmental health problem affecting both
developed and developing countries. This is a truly global concern involving ambient air
quality in cities as well as indoor air quality including the workplace, in both rural and
urban areas. The highest air pollution exposures occur in the indoor environment
particularly in developing countries. Cooking and heating with solid fuels, that is wood,
coal, dung, crop residues and charcoal, still occurs for over half the world's
population. A deadly combination of solid fuels, inefficient stoves and poor ventilation
triggers off a complex mix of health damaging pollutants in homes.
In India, where 80% of households use solid fuel, there are estimates
that half a million children die annually from indoor air pollution, especially from acute
respiratory infections. The figure for sub-Saharan Africa is roughly the same. In Latin
American countries, where one quarter of households use solid fuels, an estimated 30 000
people die each year from acute respiratory infections attributable to indoor air quality.
So much about the myth of clean country air. In fact, nearly
three-fifths of the total global exposure to particulate matter, one of the most
ubiquitous air pollutants, occurs in the rural areas of developing countries. Worldwide,
this translates into as many as three million deaths a year.
As always seems to be the case, it is the world's poorest people
who suffer most. As a rule, they face a cocktail of risk factors of which air pollution is
just one; others include malnutrition, unsafe water and poor health care infrastructure.
Malnutrition, unsafe water and use of solid fuels indoors together cause over one quarter
of all deaths in the least developed countries.
Children are of particular concern. They are especially vulnerable to
high levels of air pollution. The Global Burden of Disease study conducted by WHO in 1990,
has clearly shown that 30% of the estimated number of deaths from all diseases occur
before 15 years of age, but for acute respiratory diseases, the figure is twice as high. A
WHO Task Force on the Protection of Children's Environmental Health has been created
to address these problems.
Despite increasing knowledge about harmful health effects of air
pollution, preventive action is often slow to follow. "WHO would like to provide its
191 Member States with irrefutable evidence that air pollution causes disproportionately
heavy burden of disease," explains Dr Michael Repacholi, WHO Coordinator,
Occupational and Environmental Health. "We'd like to provide them with a sound
environmental policy framework and actions applicable to different settings and to
different socio-economic conditions. In short, we'd like to provide them with a
proper strategy to eliminate avoidable air pollutants and thus reduce this disease burden
in a cost-effective way."
This week's meeting in Geneva identified major peaks to be scaled
on the way to creating a WHO strategy on air pollution and health. In public health terms,
air pollution is not an exact science. Often, health effects that may be attributable to
air pollution can also be closely linked to other risk factors. That is why establishing a
health effects database on air pollution is seen by WHO as an important stepping stone
towards achieving these goals. But first, all parties involved should hammer out a unified
methodology for collecting comparable data world wide to support sound, science-based
assessments of health impacts.
The database will help to identify hotspots of health-threatening air
pollution levels and populations of high risk. It will also help keep track of major
sources of pollution and their effect on public health. Economic costs to society and
individuals of health impairment due to air pollution, as well as cost-effective
intervention strategies, will also be addressed by WHO.