SAFE air pollution limits are being breached in a heavily residential area of Bolton, an analysis has shown.

St Helens Road in Bolton recorded an average level of nitrogen dioxide of 42.3 micrograms per cubic metre of air in 2018, the latest year for which data is available.

That is according to research by environmental campaigners Friends of the Earth, which analysed council reports on nitrogen dioxide in the air at monitoring sites across England.

Cllr Martin McMulkin, who is an environmental campaigner, described the figures as a “matter of concern”.

The average must be below 40 to meet government air quality targets, while World Health Organisation guidelines set this as a safe limit to protect public health.

According to Friends of the Earth, road traffic is the leading cause of nitrogen dioxide pollution, which can inflame the lining of the lungs and reduce immunity to infections such as bronchitis.

Cllr McMulkin said: “This is a matter of concern ­— it has been established that road traffic fumes account for a fifth of green house gases in the UK.

“Air pollution causes heart and lung disease and St Helens Road is a residential areas so this will be impacting on the health of people who live there.”

Cllr McMulkin said the borough could take advantage of people’s change in attitudes prompted by the covid crisis.

He said: “There has been an exponential increase in cycling, we have the schemes, such as the Bee line in parts of Bolton but more needs to be done.”

Cllr McMulkin said he has been asking when Bolton Council would reconvene to discuss the Climate Emergency motion, passed by councillors, to discuss how the borough moves forward in the wake of coronavirus.

The number of sites was down from seven in 2016 and three in 2017.

Nationally, 1,360 sites failed to meet the 40 micrograms target in 2018. Although this was down from 1,591 the previous year, Friends of the Earth said the figure was still shocking.

The group’s clean air campaigner Simon Bowens said: “Failing to fix air pollution costs lives. It also shows a failure to address the climate crisis. If ministers want to avoid a return to the health-damaging and illegal levels of air pollution we had before lockdown, their enthusiasm for ‘active travel’ needs to be permanent and not just a short-term gap plugger.”

The Government recently announced plans to boost cycling and walking, including a pledge to build thousands of miles of bike lanes, which will be paid for by £2 billion of funding announced earlier this year.

Across the North West, 81 sites recorded annual averages that failed to meet air quality standards, one of which registered levels of more than 60 micrograms per cubic metre.

A Department for Environment, Food and Rural Affairs spokesman said: “Air pollution has reduced significantly since 2010 – emissions of nitrogen oxides have fallen by 33 per cent and are at their lowest level since records began.

“But we know there is more to do, which is why we are taking urgent action to curb the impact air pollution has on communities across England through the delivery of our £3.8 billion plan to clean up transport and tackle NO2 pollution.”