Schools in London will receive an alert every time air pollution in the capital is set to pose an acute risk to health as part of a renewed push to highlight the scale of the capital’s toxic pollution crisis.

Air pollution causes about 40,000 early deaths a year in the UK – more than 9,000 in London – and the young are particularly vulnerable.

The mayor of London, Sadiq Khan, already sends alerts to train stations and bus stops when pollution levels reach dangerous levels, advising vulnerable groups including children and the elderly to take precautionary measures.

Next week the system is to be extended to include schools, and GPs’ surgeries and care homes will be included “in the near future”.

Khan said: “I want more Londoners to engage with air quality issues so I am sure the new guidance that I have published today will encourage people to learn more about the air they breathe and what they can do to improve it.”

The scale of London’s air pollution crisis was laid bare last year with new figures showing that every person in the capital is breathing air that exceeds global guidelines for one of the most dangerous toxic particles.

The findings, described as “sickening” by Khan, have serious health implications – especially for children – with both short- and long-term exposure to these particulates increasing the likelihood of respiratory and cardiovascular diseases. Health experts say young people exposed to these toxic pollutants are more likely to grow up with reduced lung function and to develop asthma.

The decision to send alerts to schools comes as environment minister Thérèse Coffey is due in Brussels on Tuesday to explain to the European commission why the UK still breaches legal air pollution limits.

Britain is one of the five member states to have received a “final warning” from the commission after persistently surpassing limits for nitrogen dioxide levels.

Khan has written to the EU environment commissioner, Karmenu Vella, who will meet Coffey on Tuesday to set out his efforts to tackle air pollution and what the government needs to do.

The government was back in the UK courts last week to defend their current air pollution plans which have previously been ruled so poor that they are illegal.

A spokesman for the Department of Environment Food and Rural Affairs said air pollution “has improved significantly since 2010, but we recognise there is more to do, which is why we have put in place a £3.5bn plan to improve air quality and reduce harmful emissions.”