Damian Carrington Environment editor
Tuesday 5 December 2017 23.30 GMT
Air pollution significantly increases the risk of low birth weight in babies, leading to lifelong damage to health, according to a large new study.
The research was conducted in London, UK, but its implications for many millions of women in cities around the world with far worse air pollution are “something approaching a public health catastrophe”, the doctors involved said.
Globally, two billion children – 90% of all children – are exposed to air pollution above World Health Organization guidelines. A Unicef study also published on Wednesday found that 17 million babies suffer air six times more toxic than the guidelines.
The team said that there are no reliable ways for women in cities to avoid chronic exposure to air pollution during pregnancy and called for urgent action from governments to cut pollution from vehicles and other sources.
“It is an unacceptable situation that there are factors a woman cannot control that adversely affect her unborn baby,” said Mireille Toledano, at Imperial College London, and who led the new research published in the British Medical Journal (BMJ).
The study analysed all live births in Greater London over four years – over 540,000 in total – and determined the link between the air pollution experienced by the mother and low birth weight, defined as less than 2.5kg (5.5lbs). The scientists found a 15% increase in risk of low birth weight for every additional 5 micrograms per cubic metre (µg/m3) of fine particle pollution.
The average exposure of pregnant women in London to fine particle pollution is 15µg/m3, well below UK legal limits but 5µg/m3 higher than the WHO guideline. Cutting pollution to that guideline would prevent 300-350 babies a year being born with low weight, the researchers estimated. “The UK legal limit is not safe and is not protecting our pregnant women and their babies,” said Toledano.
“We know that low birthweight is absolutely crucial,” she said. “It not only increases the risk of the baby dying in infancy, but it predicts lifelong risk of diabetes, cardiovascular disease etc. You are setting in stone the whole trajectory of lifelong chronic illness.”