Two-thirds of the affected infants - over 12 million - live in South Asia and are exposed to pollution six times higher than recommended limits. Delhi's air pollution is now discussed at worldwide level as the air pollution in the capital is worst in the world and in during winters its impact is severe.
The UNICEF report notes that breathing in particular air pollution can damage brain tissue and undermine cognitive development which he said can set children back and have a lasting effect on their progress in life.
It explains that ultrafine pollution particles are so small that they can enter the blood stream, travel to the brain, and damage the blood-brain barrier, which can cause neuro-inflammation.
Research has also proven that there is a link between prenatal exposures to high levels of air pollution and even delays the development of kids, as well as affect the psychological and behavioural problems later during their childhood, which include symptoms of attention that deficit hyperactivity disorder, anxiety and depression.
"The brains of babies and young children are constructed by a complex interplay of rapid neural connections that begin before birth", said Pia Rebello Britto, the UNICEF chief of early childhood development. "It also benefits their societies - realized in reduced health care costs, increased productivity and a safer, cleaner environment for everyone", he stressed.More news: Quake hits Uttarakhand, tremors felt in Delhi, Haryana
The paper outlined steps for parents to take at home, focusing on monitoring children's respiratory health and reducing their exposure to fumes produced by cooking or heating fires or smoking tobacco.
UNICEF warns that as more countries grow into modern, urban societies, governments have failed to provide "adequate protection and pollution reduction measures" to protect young children.
Rees believes that smart urban planning - including affordable access to public transport, parks and green spaces for children, and better waste management to prevent open-air burning - will help bring pollution levels down. Breastfeeding and good nutrition to improve the immunity would also contribute towards healthier future for children.
The findings come at the time when India is facing the serious issue of air pollution.
Stating the obvious yet ignored, he added: "Protecting children from air pollution not only benefits children". The result of same has deteriorated lungs of many children in Delhi and the pollution levels are affecting fetuses too.