The World Health Organisation (WHO) says millions of children die each year because of environmental hazards and one in five children in the poorest parts of the world will not reach their sixth birthday, mainly because of environment-related diseases.
According to a new WHO report the deaths of 4 million children under the age of five each year can be attributed to such hazards as polluted air or water, or exposure to chemicals.
The report highlights in particular the susceptibility of children to harmful chemical exposure at different periods of their growth and says their age at the time of exposure may be just as important as the magnitude of the exposure.
The report by an advisory group of 24 scientific experts, representing 18 countries says that poisonings, acute respiratory infections, diarrhoeal diseases and malaria carried by mosquitoes which thrive in dirty water are the culprits in the majority of the deaths.
The new study has focused on the child, including the developing embryo, fetus, infant and adolescent, and on the need to have a good understanding of the interactions between exposure, biological susceptibility, and socioeconomic and nutritional factors at each stage of a child's development.
Worst hit are children living in poor and degraded environments where neglect and malnourishment render them particularly vulnerable.
Children living in unhealthy housing, lack clean water and sanitation services, and have limited access to health care and education.
The report reveals that lead is more toxic to children whose diets are deficient in calories, iron and calcium and more than 30% of the global burden of disease in children can be attributed to environmental factors.
Many other environmental threats such as pesticides in food alter the delicate organism of a growing child and may cause or worsen disease and induce developmental problems.