Data from more than 300,000 UK Biobank participants show that air pollution can raise older people’s risk of a condition causing unbearably itchy skin.
Summary
UK Biobank participants living in areas with high air pollution are more likely to develop atopic eczema late in life. Almost 16% of late-life eczema cases could be prevented by cutting air pollution in the worst-affected areas, the researchers estimate. They suggest that studies such as this one should be a wake-up call for politicians and policymakers to push for cleaner air solutions.
People living in areas with high air pollution are more likely to develop atopic eczema late in life than people who live with less air pollution, data from more than 300,000 UK Biobank participants have revealed.
I think the only way to reduce the risk for eczema and many other diseases is to use clean energy and to reduce the emission of pollutants.
Professor Minxue Shen, Central South University, China
“I think the only way to reduce the risk for eczema and many other diseases is to use clean energy and to reduce the emission of pollutants,” says Minxue Shen, one of the study’s co-leaders from China’s Central South University.
Studies such as this one should be a wake-up call for politicians and policymakers, agrees Megan Park from the University of Toronto, Canada, who independently studies the link between pollution and eczema.
Not just a childhood disease
Atopic eczema (also called atopic dermatitis) is a skin condition that can cause inflammation and itching so severe that it affects daily life and sleep. Getting a diagnosis is often harder for older people because their cases don’t fit with the idea of eczema as a childhood disease. Treatment is also more difficult because some common eczema medications suppress the immune system, which can be dangerous for people who might already have other health conditions.
How likely someone is to develop eczema later in life is, at least in part, inherited. But for older people, air pollution seems to play an even larger role, Shen found when his team looked at information from nearly 338,000 UK Biobank participants.
The role of air pollution
The researchers estimate that almost 16% of late-life eczema cases could be prevented by cutting air pollution in the worst-affected areas. Only around 6% of similar cases could be prevented by decreasing someone’s inherited risk – something that’s not possible in practice.
The team found that black carbon – tiny airborne particles from things such as diesel cars, wood-burning stoves and forest fires – were particularly concerning. “We think there’s no safety threshold of air pollutants in the prevention of eczema,” Shen says.
Park says that the results are a huge step towards understanding how the condition develops later in life because the study specifically looked at older adults. “It also had data on environmental factors, socioeconomic status, lifestyle, medical history, genetic risk, all of which are quite difficult to find in population-based studies,” she adds.
A call for action
The more we publish data on how environmental factors affect our diseases, the more it will encourage a change in health policies.
Megan Park, University of Toronto, Canada
While it’s not yet possible to say that air pollutants cause eczema – only that there’s a strong link between the two – tests on mice suggest that black carbon doesn’t affect the skin when it’s applied directly. “Our hypothesis is that air pollutants may induce skin inflammation through the respiratory system,” Shen explains.
Air purifiers at home and wearing masks when outside in highly polluted areas could be short-term solutions for people who are worried about their risk, Shen suggests. But long-term change is ultimately needed, he adds. “The more we publish data on how environmental factors affect our diseases, the more it will encourage a change in health policies,” Park says.
