Londoners were warned of 'very high' pollution levels earlier this year AFP/Getty Images           

A call was made today for the Mayor’s “toxic air day” warnings to include a reminder to schoolchildren to take their asthma medication.

A pioneering study of secondary school pupils with asthma in the capital found almost half were not treating themselves properly — putting themselves at risk of a more severe attack.

The UK already has a “disproportionately high” rate of child asthma deaths, and one in 11 children in the country suffers from the lung condition.

Sadiq Khan began issuing “very high pollution” alerts in January to alert Londoners to “filthy air”.

The professor overseeing the study believes they could help address the poor control of the condition and lack of knowledge among asthmatic children. Professor Jonathan Grigg, who also runs a severe asthma clinic at the Royal London hospital, said: “If you have asthma and it is not well-controlled, you are going to be more likely to suffer from these days of high pollution.

“If you have poor control, you run a risk of having a severe episode. The number of children who die is very small, but we are not really treating asthma as seriously as we should. In other countries, they say, ‘If you have got asthma, make sure you take your medication on the next few days’. That is what I would do. I would say, ‘There is an air pollution event. Make sure you take it.’ ” 

The research, at Queen Mary University of London, asked nearly 700 pupils with doctor-diagnosed asthma at 24 secondary schools in the capital about their use of inhalers.

It found that 42 per cent felt uncomfortable about using their “reliever” inhaler at school and that 29 per cent did not use it when feeling wheezy. More than 54 per cent of those prescribed with a twice-daily “preventative” corticosteroid inhaler did not use it as prescribed — with more than four in 10 admitting they did not know its purpose. It found that children who failed to use their inhaler did so because they were embarrassed, forgetful or found homework or other extracurricular duties got in the way.

Lead researcher Katherine Harris said it was the first childhood asthma study carried out in schools: “We know from previous work about asthma in children that there were high levels of hospitalisation and asthma-related deaths were higher than Europe. 

“One reason could be due to poor levels of asthma control in children. What we concluded is that there is a prevalence of poor control in children. There are also low levels of knowledge. A lot of children don’t understand what their medication does or how it was helping them.”