Nearly two million new cases of paediatric asthma globally a year

Otautahi - Nearly two million new cases of paediatric asthma every year may be caused by a traffic-related air pollutant, a problem particularly important in big cities around the world, according to a new study.

The research is the first to estimate the burden of paediatric asthma cases caused by the traffic pollutant in more than 13,000 cities from Los Angeles to Mumbai.

Asthma is a chronic condition affecting the airways. New Zealand has a high prevalence of asthma, with one in seven Kiwi children aged 2 to 14 years and one in eight adults taking asthma medication.

The George Washington University study found nitrogen dioxide puts children at risk of developing asthma and the problem is especially acute in urban areas. the findings suggest clean air must be a critical part of strategies aimed at keeping children healthy.

Researchers looked at ground concentrations of nitrogen dioxide, or NO2, a pollutant that comes from tailpipe vehicle emissions, power plants and industrial sites. They also tracked new cases of asthma that developed in children from 2000 until 2019.  

Out of the estimated 1.85 million new paediatric asthma cases attributed to NO2 globally in 2019, two-thirds occurred in urban areas.

The fraction of paediatric asthma cases linked to NO2 in urban areas dropped recently, probably due to tougher clean air regulations put in place by higher income countries like the United States.

Despite the improvements in air quality in some parts of the world, dirty air and particularly NO2 pollution, has been rising in South Asia, Sub-Saharan African and the Middle East.

Paediatric asthma cases linked to NO2 pollution represent a large public health burden for South Asia and Sub-Saharan Africa.

Much more needs to be done in higher income countries and in parts of the world still struggling to curb harmful emissions from vehicles and other sources of NO2, the researchers say.

They say 1.8 million excess deaths can be linked to urban air pollution in 2019 alone. A total of 86 percent of adults and children living in cities around the world are exposed to a level of fine particulate matter that exceeds the guidelines set by the World Health Organisation.

Reducing fossil fuel-powered transportation can help children and adults breathe easier and may pay big health dividends, such as fewer cases of paediatric asthma and excess deaths. At the same time, it would also reduce greenhouse gas emissions, leading to a healthier climate.