The average concentration of pollutants in Oldham’s air is once again exceeding the legal limit after a downturn in 2020.

A year-long survey was taken at 222 monitoring locations across Greater Manchester, including nine in Oldham over the course of 2021.

In 2020, 16 locations across the city region, and none in Oldham, were exceeding the legal limit.

In 2021, this figure nearly tripled – with 45 measured locations across the region exceeding legal limits, including one of the nine sites measured in Oldham.

Four more locations in Oldham were identified to be ‘at risk of exceeding’ the legal limit, with three rated ‘compliant’ and one ‘very compliant’.

It's a trend visible across Greater Manchester, with several monitoring stations reporting worse air quality than they did in 2020.

The data is collected using an analysis of ‘diffusion tubes’ – small tubes that passively measure the concentration of nitrogen dioxide in the air.

Nitrogen dioxide is produced during the burning of fossil fuels – such as those used in cars.

Each diffusion tube is left in place for one month at a time, and repeat readings are taken over the course of one year.

The Department for Environment Food & Rural Affairs publishes details of how the data is captured on its website.

Oliver Lord, UK head of the Clean Cities Campaign, said: “This is really worrying. The number of areas being monitored for the Greater Manchester Clean Air Plan that exceeded or were at risk of exceeding illegal air quality limits increased by 50 per cent in 2021.

“These limits were meant to be met in 2010. Or, to put it another way, thousands of kids leaving primary school this summer have spent their entire lives breathing illegally polluted air.

“With the drop in air pollution at the height of the pandemic, the mayor was rallying us all to ‘build back better’ but clearly this has been forgotten.

The Oldham Times: Oliver Lord, UK head of the Clean Cities CampaignOliver Lord, UK head of the Clean Cities Campaign

“Cancelling the Clean Air Zone is an open invitation for dirty vehicles to return to our streets.”

Pete Abel, a sustainable transport coordinator for Manchester Friends of the Earth, said: “The 2020 results are proof that if you take a chunk of traffic off the road, if you reduce the number of miles driven, then air pollution reduces.”

A Clean Air GM spokesperson said: “Tackling the health impact of poor air quality remains a priority for Greater Manchester and our new proposals for an investment led, non-charging Clean Air Plan will still achieve this.

“Our original proposal for a charging Clean Air Zone was developed pre-Covid pandemic. Travel restrictions during the pandemic led to a significant reduction in vehicle traffic and associated emissions, and lower concentrations of air pollution.

“While overall traffic levels were still below pre-pandemic levels in the year ending 2021, the period had higher road traffic levels than 2020.

“This is considered to be a factor behind the annual increase in nitrogen oxide (NO2) levels and is reflected in the latest diffusion tube data.

“However, the previous Clean Air Plan became unworkable due to changes in the global vehicle supply chain linked to the pandemic and the emerging cost-of-living crisis.

“The Case for a new Greater Manchester Clean Air Plan sets out the evidence supporting an investment led, non-charging Clean Air Plan as the best solution to address the roadside nitrogen dioxide (NO2) problem and clean up the city region’s air, in a way that does not does not put jobs, livelihoods and businesses at risk.”