Fine particles such as road dust and exhaust fumes may contribute to children developing asthma and suffering from breathing difficulties. This is shown by a new large-scale study from Aarhus University.

2020.08.20 | Helle Horskjær Hansen

Torben Sigsgaard from the Department of Public Health, Aarhus University, is behind the study based on more than 800.000 Danish children.

The study documents that children who are exposed to higher levels of fine particles in the air – such as road dust, exhaust fumes and wood-burning stoves – are more likely to develop asthma and develop breathing difficulties than children who are not exposed.

The results have just been published in British Medical Journal.

Penetrate into the lungs

The fine particles, which are the culprit, can penetrate deep into the lungs, and some can even enter the cardiovascular system.

Torben Sigsgaard from the Department of Public Health, Aarhus University, is behind the study.

"We also found other risk factors that are associated with a higher risk of developing asthma and breathing problems. Having a parent with asthma, a mother who smokes during pregnancy or parents with shorter educations and low income," he explains.

In contrast, the researchers did not find so many children with asthma and breathing difficulties among children of parents with higher education and higher incomes.

Confirms previous studies

Their findings are based on more than 800.000 Danish children born between the years 1997-2014. Of these, almost 123,000 were identified with asthma and breathing difficulties – the average age for this was 1.9 years.

Information on asthma incidence, parental asthma, maternal smoking, air pollution, and parental education and income was derived from nationwide health registries linked with detailed modelled daily air pollution concentrations.

"As this is an observational study, we can’t determine the exact cause," says Torben Sigsgaard, and points to some limitations in the study such as a lack of information about nutrition and physical activity and factors related to the children's indoor environment.

"However, the study’s strengths are that it includes such a large number of children from all social classes and a broad age group," he says.

At the same time, the study confirms that air pollution is a significant factor in asthma when correcting for risk factors identified in previous studies in the area.

"The results suggest that reduced air pollution from fine particles may help to reduce the number of children who develop asthma and have breathing difficulties among vulnerable population groups," says Torben Sigsgaard.

Background for the results

• The study is financed by NordForsk – The Nordic Programme on Health and Welfare, and BERTHA – a Novo Nordisk Foundation  ”Challenge Programme.”
• It is an observational study
• The scientific article is published in BMJ.
  

Contact

Torben Sigsgaard,
Department of Public Health, Research Unit for Environment, Work and Health, Aarhus University
Phone: (+45) 2899 2426
Email: ts@ph.au.dk