The report notes that breathing in particulate air pollution can damage brain tissue and undermine cognitive development - with lifelong implications and setbacks. Previously Centre for Science and Environment (CES) study revealed the same could possibly cause premature deaths among young children.

Severe air pollution can also lead to other neurological disorders like Attention Deficit Hyperactivity Disorder (ADHD).

Satellite imagery reveals that South Asia has the largest proportion of babies under the age of one living in the worst-affected areas, with 12.2 million babies residing where outdoor air pollution exceeds six times global limits set by the World Health Organization (WHO).

"The numbers are very concerning for public health", said Rachel B. Smith, a research associate in the School of Public Health at Imperial College London who was not involved in the UNICEF report. This once entered into the brains causes neuroinflammation, which have been linked to causing Alzheimer's and Parkinson's diseases in elderly people.

After a lot of researches, it has been found that the pollutants can even cross the placenta and adversely affect the developing brain of a foetus permanently. "Children also breathe more rapidly and are more likely to breathe through their mouths, which increase the number of pollutants they inhale".

The United Nations report was titled as "Danger in the air", that states that brain damage can happen through several mechanisms.

Likewise, another major air pollutant is the magnetite nanoparticles similar to ultrafine PM.

Some pollution particles can cause neurodegenerative diseases while others can damage brain areas for learning and development. Unfortunately, these chemicals are now in abundance in the nation's capital New Delhi.

Lake called on countries exceeding global limits to step up efforts to reduce air pollution.

"No child should have to breathe dangerously polluted air - and no society can afford to ignore air pollution", said Lake.

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.

The Unicef elaborates the effects says the risk begins in the womb.

The report finds a possible link between prenatal exposures and delayed development of an infant's brain, along with psychological and behavioural problems that may occur later in childhood.