Air pollution biggest threat for children, 6 lakh died in 2016 by inhaling polluted air, says WHO report

Air pollution is one of the leading threats to child health, accounting for almost 1 in 10 deaths in children under five years of age. In 2016, approximately 6 lakh children died due to acute lower respiratory infections caused by polluted air, as per a report by the World Health Organisation. WHO in its report states that on a daily basis, around 93 per cent of the world’s children under the age of 15 years breathe air that is so polluted that it puts their health and development at serious risk. 

In its report on air pollution and child health, the WHO examines the heavy price that children have to pay due to pollution both inside and outside the homes. The report reveals that when pregnant women are exposed to polluted air, they are more likely to give birth prematurely, and have small, low birth-weight children. 

Air pollution also has a negative impact on the neurodevelopment and cognitive ability which can trigger asthma, and childhood cancer. Children who have been exposed to high levels of air pollution may be at greater risk for chronic diseases such as cardiovascular disease later in life.

The researchers recruited 1285 women in the first trimester of pregnancy in primary health care centres and urban health posts and followed them until the birth of their child to collect data on maternal health, prenatal care, exposure to air pollution during pregnancy and the birthweight of the child.

It was found that a 10 μg/m3 increase in exposure to particulate matter (PM2.5) levels during pregnancy was associated with a decrease in birth weight of 4g and a 2% increase in the prevalence of low birth weight. 

In India, infants born to women who used biomass fuels such as wood and/or dung as the primary cooking fuel in the home during pregnancy were more likely to be small for gestational age
. Most of the research on household air pollution
 has been on the effects of ambient air pollutants, although infants spend most of their time indoors. In a study in rural India, the risk of infant mortality was 21% higher in households with indoor burning of biomass fuels (wood or dung) than in those in which kerosene or biogas was used.

A population-based cohort study of exposure to indoor biomass fuel and tobacco smoke and the risks of various adverse health outcomes in newborn infants in south India found that infants exposed to household air pollution were at a 30% higher risk of being stunted at 6 months of age. The research suggests that switching from polluting to clean fuels could substantially reduce the risk of child stunting and other adverse health outcomes.

The association between exposure to household air pollution from solid fuel combustion and TB has also been evaluated in a few studies. Exposure to biomass fuel combustion exhaust was found to prevent macrophages in the lung from functioning correctly. As macrophages have a key role in the immune response to infection, these changes may increase the vulnerability of individuals to TB and other respiratory infections.

Several studies have also found that indoor cooking with polluting fuels leads to the development of asthma in children. Studies in India and Nepal found a statistically significant increase in the risk of asthma with indoor use of biomass fuel stoves, especially in the absence of appropriate ventilation. In contrast, a study in Malaysia found no association between exposure to household wood stoves and a first hospitalization for asthma of children aged 1 month to 5 years. 

"Polluted air is poisoning millions of children and ruining their lives. This is inexcusable. Every child should be able to breathe clean air so they can grow and fulfil their full potential," Dr Tedros Adhanom Ghebreyesus, WHO Director-General said.

One reason why children are particularly vulnerable to the effects of air pollution is that they breathe more rapidly than adults and so absorb more pollutants. They also live closer to the ground, where some pollutants reach peak concentrations – at a time when their brains and bodies are still developing.