In 2015, 5.9 million children under age five died. The major causes of child deaths globally are pneumonia, prematurity, intrapartum-related complications, neonatal sepsis, congenital anomalies, diarrhoea, injuries and malaria. Most of these diseases and conditions are at least partially caused by the environment. It was estimated in 2012 that 26% of childhood deaths and 25% of the total disease burden in children under five could be prevented through the reduction of environmental risks such as air pollution, unsafe water, sanitation and inadequate hygiene or chemicals.
Children are especially vulnerable to environmental threats due to their developing organs and immune systems, smaller bodies and airways. Harmful exposures can start as early as in utero. Furthermore, breastfeeding can be an important source of exposure to certain chemicals in infants; this should, however, not discourage breastfeeding which carries numerous positive health and developmental effects. Proportionate to their size, children ingest more food, drink more water and breathe more air than adults. Additionally, certain modes of behaviour, such as putting hands and objects into the mouth and playing outdoors can increase children’s exposure to environmental contaminants.