World Health Day

Healthy environments for children: WHO backgrounder N°3, April 2003

A major threat to children’s health and lives needs action now

Over five million children per year ages 0-14 years old die from illnesses and other conditions caused by the environments in which they live, learn and play. Yet the linkages between children’s environments and their chances of good health are often poorly understood. World Health Day this year is about galvanizing action and raising awareness about the linkages between children’s environments and their health. The issues are clear.


Children have a unique vulnerability. As they grow and develop, there are “windows of susceptibility”: periods when their organs and systems may be particularly sensitive to the effect of certain environmental threats.

Children are particularly vulnerable to environmental hazards because they are constantly growing, and consume more food, air and water than adults do in proportion to their weight. Their immune, reproductive, digestive and central nervous systems are still developing and they spend their time closer to the ground where most dust and chemicals accumulate.

Children can also be exposed to harmful environmental hazards before birth, for instance through maternal addiction to tobacco and other substances. Exposure to environmental risks at early stages of development can lead to irreversible damage


Of the global total burden of disease, a substantial proportion (perhaps up to one third) is caused by environmental risk factors, and 40% of this falls on children under five (who constitute only 10% of the world's population). Some of the most telling statistics are:

Household Water Security

  • In 2000, it was estimated that 1.1 billion people lacked access to an improved water source .
  • The most important disease related to inadequate access to safe drinking water is diarrhoea - the second biggest child-killer in the world after acute respiratory infections. Diarrhoea is estimated to cause 1.3 million child deaths per year - about 12% of total deaths of children under five in developing countries.
  • Other infectious diseases with similar patterns of transmission affecting children include hepatitis A and E.
  • Lack of household water security is also associated with skin and eye infections including trachoma, and with schistosomiasis, which may be acquired whilst collecting water from infested sources.

Hygiene and Sanitation

  • Globally, 2.4 billion people, most of them living in peri-urban (transition between rural and urban) or rural areas in developing countries, do not have access to any type of improved sanitation facilities (access to facilities likely to be sanitary.
  • The lowest levels of facility coverage are found in Asia and Africa where 31% and 48% of the rural populations, respectively, do not have access to improved sanitation facilities.
  • Even if improved sanitation facilities are available, they are not always enough to improve people’s health: children and adults must be encouraged to wash their hands with soap or ash before meals and after defecating.
  • Inadequate hygiene contributes to diarrhoeal diseases, which may result from contaminated water and food. Contaminated food, especially complementary food (foods given to infants to complement mother’s milk) is one of the leading causes of infant diarrhoea leading to illness and death, particularly in developing countries.

Air Pollution

  • Air pollution is a risk factor for both acute and chronic respiratory disease as well as other diseases: around two million children under five die every year from acute respiratory infections. Many of these deaths are aggravated by environmental hazards.
  • Both indoor air pollution (from, for example, the combustion of biomass fuel and coal, and environmental tobacco smoke) and outdoor air pollution, mainly from traffic and industrial processes, are serious problems. It is estimated that a quarter of the world’s population is exposed to unhealthy concentrations of air pollutants such as particulate matter, sulphur dioxide, and other chemicals.

Disease Vectors

  • In principle, all vector-borne diseases are a serious threat to children's health. The presence of vectors (including mosquitoes and worms) is often the result of insufficient water resource management (for example, stagnant pools of water). Some vector-borne diseases pose a specific threat to children, because a child’s immune system is unable to cope with the assault by the infectious agent, or because of the way a child behaves may increase vulnerability to disease.
  • Malaria alone is responsible for around one million deaths per year of children, many of them under five and most in Africa.
  • Schistosomiasis, Japanese encephalitis, leishmaniasis and dengue fever are also particular threats to children and cause large burdens of mortality and morbidity among them.

Chemical Hazards

  • About 50,000 children, aged 0-14 years old, die every year as a result of unintentional poisoning.
  • Chemical pollutants are released into the environment by unregulated industries or are emitted from heavy traffic or toxic waste sites.
  • Pesticides unsafely used, stored and disposed of may harm children and their environment. Household cleaners, kerosene, solvents, pharmaceuticals and other chemical products become dangerous if they are kept in inappropriate containers and in places that are accessible to children.

Unintentional Injuries

  • In 2001, an estimated 685,000 children under the age of 15 were killed by unintentional injuries
  • Unintentional injuries include road traffic injuries, poisonings, falls, burns and drowning.
  • The vast majority of unintentional injuries among children occur in low and middle-income countries: children in the African, South-East Asian and Western Pacific regions account for 80% of all children’s deaths from unintentional injuries.
  • Approximately 20% of all deaths from unintentional injuries world-wide occur in children under 15 years old and they are among the ten leading causes of death for this age group.
  • World-wide, the leading causes of death from unintentional injury among children are road traffic injuries (21% of such for this age group) and drowning (19%).


There are a number of simple, low-cost, effective and sustainable measures to combat the environmental risks to our children. These can be undertaken at home or in schools.

Household Water Security

  • Safe water storage at home – and treatment of water in the home when its quality is in doubt - reduces water contamination and leads to proven health benefits.

Hygiene and Sanitation

  • Washing hands with soap before food preparation, before meals and after defecating significantly reduces the risk of diarrhoeal disease.
  • Follow the WHO Five Keys to Safer Food to reduce the risk of foodborne disease: keep clean; separate raw and cooked; cook thoroughly; keep food at safe temperatures; and use safe water and raw materials.

Air Pollution

  • Good ventilation in the home, clean fuels and improved cooking stoves decrease indoor air pollution and the exacerbation and development of acute respiratory infections.

Disease Vectors

  • As children usually go to bed earlier than adults at the time mosquitoes become active, the use of insecticide-treated mosquito nets and the screening of windows, doors and eaves provide a very effective means of protecting them against malaria.

Chemical Hazards

  • Ensure safe storage, packaging and clear labelling of cleaners, fuels, solvents, pesticides and other chemicals used at home and in schools.

Unintentional Injuries

  • Advocate for safer roads and organized traffic.


In 2002, at the World Summit on Sustainable Development, WHO and its partners launched a new initiative – an alliance on Healthy Environments for Children. The Alliance has adopted a new framework both for highlighting environmental risks – grouping them into six priority areas – and for orienting prevention and response activities to the places where children spend their time – the home, the school and their community.

Since the Alliance’s launch, activities have centred on the formation of a broad-based movement encompassing organizations ranging from the global to the local and including governments, intergovernmental organizations, nongovernmental organizations, academic institutions and private sector groupings.


7 April 2003 is a springboard to encourage the Alliance and all other parties with an interest in improving children’s health to implement these and other measures in their countries and communities. Those who participate in the Alliance will work – together - to shape the future: to make sure that our children grow up safe, healthy and happy. They will then be best able to become the future guardians of our planet.