Rising asthma numbers: is particulate matter a cause?
Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001. In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.
More posts by Christiane Fux All content is checked by medical journalists.The number of children suffering from asthma has been increasing for years. Danish researchers have found a possible cause: particulate matter.
Researchers led by Gitte J. Horst from Aarhus University have found that the risk of asthma for children increases by 5 percent for every 5 micrograms (μg) of additional fine dust per square meter. The scientist and her colleagues analyzed the health data of all Danish children born between 1997 and 2014. In total, that was almost 800,000.
It was determined whether the children between their 1st and 15thThey were diagnosed with asthma or had been prescribed asthma medication at least twice on their birthday. That applied to around 123,000 children.
The researchers also examined the influence of various factors that are known to promote asthma. These included:
- Home air pollution twelve months before diagnosis
- diagnosed asthma illness in parents
- Mother tobacco use during pregnancy
- Parents' income and education
Horst's team compared each asthma child with 25 children of the same sex and the same week of birth who did not suffer from asthma.
Particulate matter is an asthma driver
For the period from 1997 to 2014, the researchers calculated the air pollution at the place where the children lived using models. Fine dusts with different particle sizes, but also nitrogen dioxide, sulfur dioxide and ozone were taken into account.
In fact, fine dust with a diameter of less than 2.5 μm turned out to be a particularly relevant asthma driver. In Europe, the approved concentration is 20 μg. But that is obviously not enough: Even in the permitted range, the risk of asthma increased by five percent for every 5 μg. Sources of fine dust such as traffic proved to be particularly critical.
"The combination of fine dust with allergens led to a higher level of aggressiveness of the allergens, which then lead to greater damage and a higher rate of sensitization in the lungs and respiratory tract," says Horst. This can also be shown in animal models. "The data is on a fairly secure footing."
Influence of genes and education
The study also confirmed other risk factors: If both parents suffered from asthma, the child had a 2.29 times higher risk of developing the disease themselves. If only the mother was sick, the risk was 1.71. If the father was asthmatic, the risk for the child increased to 1.51.
Smoking during pregnancy increased the risk 1.2-fold.
The overall risk of asthma was lower for children of parents with a high education or high income.
"Our results indicate that particulate matter is contributing to an increase in the number of asthma patients among children worldwide," the authors write. A reduction in particulate matter could therefore potentially reduce the number of children affected.
Tags: pregnancy birth menshealth prevention
