Some 1.3 million children under the age of five died in developing countries in 2000 from diarrhoea-linked diseases caused by dirty water and lack of hygiene, WHO said in a statement.
And it said some 60 percent of the 2.2 million child deaths caused by acute respiratory infections every year are linked with indoor air pollution, usually generated by fuel burning in confined spaces.
"The lost or compromised ability to be active which children suffer from environmental degradation is vast," it said at the start of the Conference on Environmental Threats to the Health of Children.
"Children are not 'little adults', they are in a dynamic process of growth and development and they are particularly vulnerable to the acute and chronic effects of pollutants in their environments."
More than 300 participants from around the world are expected to attend the conference, which will run until March 7.
They will discuss measures to reduce environmental impact on children, particularly those in Asia-Pacific countries.
WHO said that in Bangladesh and India, arsenic in drinking water is a persistent problem. In other countries, there are concerns about exposure to lead, which is thought to lower intelligence.
Source: AFP
