Air pollution blamed as childhood cancer climbs by 21% in ten years
– Professor Denis Henshaw
Childhood cancers have increased by more than a fifth in 10 years as experts link the rise in cases to air pollution.
As world leaders prepare to gather in Scotland to limit damaging emissions and slow global warming, Scottish figures reveal a 21% increase in childhood cancers between 2010 and 2019.
Professor Denis Henshaw, former scientific director at charity Children with Cancer UK, said research is urgently needed to establish the impact of pollution, particularly exhaust fumes, on children and mothers-to-be. He said scientists must work to establish if children diagnosed with cancer, or their mothers when pregnant, had been exposed to air pollution.
The incidence of leukaemia in young Scots has risen from 27 cases in 2010 to 41 in 2019, an increase of more than 50%, according to a report into childhood cancers released by Public Health Scotland. The figures show a 30% increase in the number of girls diagnosed with cancer compared with a 13% rise among boys.
The report into diagnostic trends in children, aged 14 and under, stated: “The annual number of new cancers in children has generally increased over time. For all children, the increase was almost 21% between 2010 and 2019. The increase in boys at 12.8%, was smaller and may be a chance finding but the increase in girls was 30.1%, larger and unlikely to be due to chance.”
Henshaw said the rise in air pollution is almost certainly a contributory factor. He said: “You have to consider what is changing and it is not our genetics but our environment, in particular air pollution from the increase in the number of cars on our roads during that time.
“It has to be a major contributor
in the rise of cancer in children”. A Scottish Government consultation document on the need for cleaner air last week revealed almost a third of Scotland’s streets have higher levels of toxic particle air pollution, caused mainly by traffic, than they did before the Covid-19 pandemic.
In 2018, Health Protection Scotland estimated that air pollution caused around 1,700 deaths in Scotland every year while the number of vehicles on UK roads increased during that time from 34 million to 38.4 million.
As Cop26 begins next week and world leaders hammer out agreements to curb emissions and the need to speed the change to greener, electric transport, Henshaw said air pollution was a factor in the rising number of childhood cancer diagnoses: “Vehicle exhaust and diesel cars are a major factor, I believe. While we consider the impact on climate change we must examine what it is doing to our health, especially that of our children.
“The rise in cancer in children is worrying and should absolutely be on the agenda of Cop26.
“The highest number of childhood cancers are leukaemias and other blood cancers which together account for 40% and the peak age is very young children, under five. From that we can deduce that they
have been exposed either in the womb or shortly after birth – the children or their mothers. We also have to look at what is in our food.
“The rise in cancer in girls is also of concern and merits investigation. We must examine the origins of the child and its mother during pregnancy and see what part their environment played in the cancer. The placenta is seen as a barrier but pollutants cross it to the baby. Lead is an example.”
Henshaw’s fears over pollution as a cancer driver in children are mirrored by Professor Catherine Metayer, of Berkeley School of Public Health in the US. Cases of childhood cancers have also risen there.
She studied environment and diet factors in the rise of childhood leukaemia and stated that populationbased studies have provided enough evidence to start prevention by reducing exposure to multiple harmful chemicals from various sources. Her studies cite the contribution of pollution to cancer in children.
She also advocates an increase in healthy diet during pregnancy, and breastfeeding.
She believes that chemicals pass the placenta and damage the foetus’s blood cells and also that germ cells in sperm before conception may play a role. Dr Robert Hughes, a clinical research fellow into early childhood development at the London School of Hygiene and Tropical Medicine and an adviser to the Clean Air Fund, agreed more research was needed on air pollution and cancer.
He said: “There is certainly a growing awareness of the way in which air pollution affects us all from cradle to grave. This rise in childhood cancer and the suggestion that air pollution
‘Rise in child cancers should be on Cop26 agenda
plays a part certainly merits more investigation.
“That said, we do not need any more reasons to act now to reduce the levels of air pollution in our towns and cities, as we already have good evidence that cleaner air can make us – and our children – healthier in several ways. For example, cleaner air will result in lower risk of babies being born too small or prematurely, healthier lung growth, and lower risk of asthma and other childhood illnesses. Pollution levels also seem to affect brain development and learning in children too.”
The Scottish Government said it last month published its first cancer care strategy for young people, backed by an investment of £6m.
It said: “We are committed to making sure the necessary support for physical and mental health is available to all who need it, when they need it.”
On the issue of air quality, it said: “Improving air quality and in turn the health of our people and planet is an urgent priority for this Government and we are taking action across the board. We work closely with local authorities to tackle air pollution issues and fund measures outlined in their Air Quality Action Plans.”