The link between air pollution and respiratory diseases is well-established, but the United Nations Children’s Fund, in a report on Tuesday, said there is a growing body of scientific research which shows that air pollution can permanently damage a child’s brain. The findings come at a time when India, particularly in the north, is facing a serious crisis due to rising levels of pollution. Last month, schools in Delhi had to be shut temporarily to reduce children’s exposure to pollutants that had enveloped that national capital.
The Unicef report also said that South Asia has the largest proportion of babies living in areas where air pollution is at least six times higher than international limits (10 micrograms per cubic metre).
The UN body said globally 17 million babies under the age of one live in such highly polluted areas, of which an estimated 12.2 million live in South Asia, which is the highest. East Asia and the Pacific have 4.3 million babies breathing toxic air.
The Unicef report, titled “Danger in the air”, explains that brain damage can happen through several mechanisms. First, it stated, particulate matters can cause neuro-inflammation by damaging the blood-brain barrier — a thin, delicate membrane that protects the brain from toxic substances.
Second, exposure to specific air pollutant particles, such as magnetite, can lead to oxidative stress which is often the cause of neurodegenerative diseases. Quoting multiple studies, the UN body said polycyclic aromatic hydrocarbons commonly found in areas of high automobile traffic contribute to a loss of or damage to white matter in the brain. White matter contains nerve fibres that are critical in helping neurons communicate across different parts of the brain. It is important for continued learning and development.
“Not only do pollutants harm babies’ developing lungs, they can permanently damage their developing brains and, thus, their futures,” Unicef executive director Anthony Lake said.
Exposure to pollutants inhaled during pregnancy is also harmful. The latest analysis of multiple researches states that pollutants can cross the placenta and affect the developing brain of a foetus. Research also shows an association between prenatal exposures to high levels of air pollution and development delay at age three, as well as psychological and behavioural problems later in childhood, including symptoms of attention deficit hyperactivity disorder, anxiety and depression. “One study reports a four-point drop in IQ by the age of five among a sample of children exposed in utero to toxic air pollution,” the report said.
“A young child’s brain is especially vulnerable because it can be damaged by a smaller dose of toxic chemicals compared to an adult’s brain. Children are also highly vulnerable to air pollution because they breathe more rapidly and also because their physical defences and immunities are not fully developed’, Unicef said.
It advised parents to reduce children’s exposure to pollutants by making it feasible for them to travel during times of the day when air pollution is lower; provide appropriately fitting air filtration masks in extreme cases.
“Improve children’s overall health to improve their resilience. This includes the prevention and treatment of pneumonia, as well as the promotion of exclusive breastfeeding and good nutrition,” the UN body said.