No schools or colleges in Dorset are in areas with high levels of one of the most harmful forms of air pollution.

That is according to research by the British Lung Foundation, which looked at locations across England with potentially dangerous levels of fine particulate matter (PM2.5).

None of the 207 nurseries, schools or colleges in Dorset included in the study were found to be in areas where PM2.5 levels are above the World Health Organization-recommended limit.

PM2.5 is the most harmful type of air pollution for human health and particularly affects children and people with lung conditions such as asthma, says the BLF.

It can penetrate deep into the lungs and even the blood, increase heart diseases and lung cancer, and leads to thousands of early deaths a year.

Traffic fumes are a major source of the pollutant, which can also be produced through industrial emissions and wood burners.

The WHO says concentrations of PM2.5 should not exceed 10 micrograms per cubic metre on average in the year – half the current legal limit in the UK of 20 micrograms.

The research used government data collected in 2019, which provides estimates of PM2.5 for small areas across the country.

The BLF said there is no “safe level of exposure” to PM2.5, and that the Government data might be an underestimate of pollution levels in some areas due to the distribution of air quality monitors.

Across the South West, 189 nurseries, schools and colleges were identified as being in areas where WHO-recommended limits were breached.

The BLF said concentrations of PM2.5 tend to be higher in urban areas of southern and eastern England, partly due to greater exposure to pollution from mainland Europe.

But it stressed that other forms of pollution such a nitrogen dioxide are at illegal levels in other parts of the country.

Across England, more than 8,500 nurseries, schools and colleges were found to be in areas where PM2.5 levels exceeded WHO guidelines.

The BLF is urging the Government to produce a national health protection plan for England to be overseen by a new air quality minister, and stronger air quality laws in line with the WHO limits.

Professor Stephen Holgate, medical adviser at the BLF, said: “We’ve known about the deadly harm air pollution can cause for decades, it’s time now for urgent action.”

Last year, Prof Holgate gave expert testimony at the high-profile inquest of nine-year-old Ella Kissi-Debrah, in which the coroner concluded that air pollution had contributed to her death from asthma.

The coroner said in a statement that nitrogen dioxide and particulate matter levels near her home in the London borough of Lewisham were in excess of WHO guidelines, and were mainly caused by traffic emissions.

Prof Holgate added: “We must honour Ella’s legacy by acting now and protecting other vulnerable people from the harmful effects of toxic air.”

Environment minister Rebecca Pow said: “Air pollution has reduced significantly since 2010 with emissions of fine particulate matter falling by 9% and emissions of nitrogen oxides at their lowest level since records began. However, we know there is more to do.

“Our landmark Environment Bill will set at least two ambitious legally-binding air quality targets, with a primary focus on reducing exposure to particulate matter pollution.

“As part of this, we will consider the World Health Organization’s guidelines for PM2.5.”