Air pollution may significantly increase the risk of babies dying in their first year of life, a major study has found.
Researchers tracked nearly eight million infants born in England and Wales between 2001 and 2012.
They found babies in the most polluted areas had a 30 to 50 per cent greater risk of dying by any cause by the age of one.
Air pollution may increase the chance of death in babies by up to 50 per cent, a study of 8million children has found
Britain’s worst pollution hotspots was outside Earls Court tube station in London where the annual average of 129.5 micrograms per cubic metre of air. That’s triple that of the World Health Organization’s 40 mcg limit, according to research last month
Experts have long warned air pollution poses a risk to health, but the new research contains some of the starkest findings yet of the extent of that harm.
Scientists say the microscopic particles emitted by cars and industry are breathed deep into the lungs and enter the blood stream.
From there it can trigger heart disease and lung cancer later in life, as well as lung infections such as pneumonia.
The observational study did not offer a reason as to why the children were more likely to die early.
Researchers at the Cardiff University School of Medicine found three separate air pollutants all independently raised the risk of babies dying.
The main culprits were nitrogen dioxide (NO2), sooty smog pumped out by old diesel cars – known as particulate matter (PM10) – and sulphur dioxide (SO2).
NO2 and PM10 are mainly released from traffic, whereas SO2 is produced from the burning of fossil fuels such as coal, oil and gas.
The research team used the UK’s Office for National Statistics to analyse data from 7,984,366 live births and deaths in England and Wales over the 12 years.
They divided the country into approximately 35,000 small areas, each with a similar population size of 1,500 residents or 650 households.
Researchers then used average annual pollution data from the Department for Environment, Food and Rural Affairs.
The team, led by Dr Sarah Kotecha, calculated how much pollution each area was exposed to before linking it to death rates.
There was a 20 to 40 per cent increased risk of death for babies aged up to one in the most polluted areas.
The doctors also found a 20 to 40 per cent increased risk of neonatal deaths – deaths that occur within 28 days of birth – in polluted areas.
And they recorded a 30 to 50 per cent spike in post-neonatal deaths, which occur between 28 days after birth and one year, in the same areas.
After adjusting for factors that could affect the results, such as deprivation, birthweight, maternal age and multiple births, the risks decreased slightly.
The chance of an infant dying was seven per cent greater in areas with high levels of NO2, four per cent for PM10 and 19 per cent for SO2.
They found that neonatal deaths increased by 21 per cent in areas plagued by SO2, but not significantly for NO2 and PM10.
And the risk of post-neonatal deaths increased by 11 per cent, 12 per cent and 15 per cent for areas high in NO2, PM10 and SO2, respectively.
The average level of the pollutants in the mot polluted areas were was 34ug/m3 for NO2, 22ug/m3 for PM10 and 6ug/m3 for SO2.
The World Health Organisation (WHO) says a safe level of NO2 is below 40ug/m3, 20ug/m3 for PM10 and under 5ug/m3 of SO2.
Dr Kotecha said: ‘We found NO2, PM10 and SO2 are each linked in varying degrees to infant deaths from any cause, and to neonatal and post-neonatal deaths.
‘This is an important finding as the pollutants are produced and derived from different sources.
‘Our findings show that although progress has been made, the challenge remains to reduce air pollution in order to reduce the numbers of infant deaths.
‘In the meantime, by understanding how pollution affects babies, either directly or via the mother, we may be able to target appropriate therapies or other interventions, depending on the amount of exposure to the different types of pollutants.’
The findings are to be presented at the European Respiratory Society International Congress on Sunday in Madrid.
Currently 36,000 Britons a year die to air pollution, costing the country £20billion annually in healthcare.
A further 29,000 people die with a range of illnesses linked to air pollution such as cancer, diabetes and chronic lung disease.
The UK is notoriously bad at controlling air pollution, with 37 cities persistently displaying illegal levels and the Government repeatedly being hauled into court over the past few years.
Diesel cars have been promoted since the 1970s as an environmentally-friendly choice because they emit less carbon dioxide.
But in recent years scientists have realised that diesel also produces more of the tiny particles and nitrogen oxides that are damaging to our health.