New WHO report tackles children's environmental health

27 JULY 2007 GENEVA -- The World Health Organization (WHO) is today releasing the first ever report highlighting children's special susceptibility to harmful chemical exposures at different periods of their growth.

This new volume of the Environmental Health Criteria series, Principles for Evaluating Health Risks in Children Associated with Exposure to Chemicals, is the most comprehensive work yet undertaken on the scientific principles to be considered in assessing health risks in children. It highlights the fact that in children, the stage in their development when exposure occurs may be just as important as the magnitude of the exposure.

The scientific principles proposed in the document for evaluating environmental health risks in children will help the health sector, researchers and policy makers to protect children of all ages through improved risk assessments, appropriate interventions and focused research to become healthy adults.

"Children are not just small adults" said Dr Terri Damstra, WHO’s team leader for the Interregional Research Unit. "Children are especially vulnerable and respond differently from adults when exposed to environmental factors, and this response may differ according to the different periods of development they are going through. For example, their lungs are not fully developed at birth, or even at the age of eight, and lung maturation may be altered by air pollutants that induce acute respiratory effects in childhood and may be the origin of chronic respiratory disease later in life."

Air and water contaminants, pesticides in food, lead in soil, as well many other environmental threats which alter the delicate organism of a growing child may cause or worsen disease and induce developmental problems. Over 30% of the global burden of disease in children can be attributed to environmental factors.

Children have different susceptibilities during different life stages, due to their dynamic growth and developmental processes. Some examples of health effects resulting from developmental exposures prenatally and at birth include miscarriage, still birth, low birth weight and birth defects; in young children, infant mortality, asthma, neurobehavioural and immune impairment; and in adolescents, precocious or delayed puberty. Emerging evidence suggests that an increased risk of certain diseases in adults such as cancer and heart disease can result in part from exposures to certain environmental chemicals during childhood.

The vulnerability of children is increased in degraded and poor environments. Neglected and malnourished children suffer the most. These children often live in unhealthy housing, lack clean water and sanitation services, and have limited access to health care and education. For example, lead is known to be more toxic to children whose diets are deficient in calories, iron and calcium. One in five children in the poorest parts of the world will not live longer than their fifth birthday, mainly because of environment-related diseases.

This central focus of this new study is on the child including 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.

The work was undertaken by an Advisory group of 24 scientific experts, representing 18 countries, and convened to provide insight, expertise, and guidance, and to ensure scientific accuracy and objectivity. Once the text was finalized, it was then sent to over 100 contact points throughout the world for review and comment, and also made available on WHO's International Programme of Chemical Safety (IPCS) web site for external review and comment for a period of 2 months.

For further information contact:
Ms. Nada Osseiran
Communications and Advocacy officer
Public Health and the Environment
WHO, GenevaTel.: +41 22 791 4475Fax: +41 22 791 4127
E-mail: osseirann@who.int

Gregory Hartl
Communications AdvisorHealth and Sustainable Development
WHO, GenevaMobile: +41 79 20 36 715
E-mail: hartlg@who.int