Brixton Road’s air pollution monitor, measuring air quality in one of the most polluted roads in the UK, has not been showing readings nearly nine months after it was first taken off line.

The monitor, which measures Nitrogen Dioxide (NO2) as well as particulate matter, was damaged after it flooded in August and was offline until it was fixed in March.

But is off line again after more damage was found.

This has warped figures around NO2 pollution in Brixton, with the monitor “the most important in the UK”, according to clean air campaigner and founder of Little Ninja, David Smith.

In January 2017, Brixton Road breached European NO2 limits for the year within five days – the first road in London to do so.

“People are saying it isn’t exceeding [NO2 limits] in January 2019 when actually it’s not working, its not online,” Mr Smith said.

“If we don’t get the information, we don’t get the scandal. You don’t get scrutiny and you don’t get the action.”

Air pollution impacts growing growing lungs the most, and increases rates of asthma, pneumonia, respiratory disease and lung cancer.

Mr Smith had set up his own air pollution monitor on Brixton Road, which showed people were exposed to nearly double the legal limit of 40 micrograms of NO2 per cubic metre.

“We have a Ultra-Low Emission Zone and low emissions buses, which are all wonderful things, but clearly more effort needs to be made because air pollution isn’t improving,” he added.

Cllr Claire Holland, Lambeth Cabinet Member for Environment & Clean Air, said: “Lambeth Council takes air quality extremely seriously, it is undoubtedly a silent killer and affects our vulnerable residents the most.

“The air quality in central London, and along Brixton Road in particular, is quite simply disgraceful and we are doing huge amounts of work in monitoring and reporting air pollution, raising awareness and knowledge, lobbying for improvements, and putting measures in place to both reduce pollution and mitigate its effects.

“The air quality monitoring station was flooded last year and took a frustratingly long time to fix, due to various contractor issues. It was back online last month but since then further damage has been uncovered and a part needs replacing before it can give accurate readings. That repair work is underway.

“Lambeth has an Air Quality Action Plan that sets out the issues we face in terms of polluted air and the measures we are taking to tackle it, including installing green screens at primary schools, working with businesses to reduce emissions by consolidating supply chains and delivery journeys and working with the Mayor and TfL for a clean bus corridor through Brixton and Streatham that was introduced in 2017.

“However, we know there is still a lot more to be done – and this year we are trialling School Streets road closures to reduce pollution and make it safer for our young people to walk or cycle to school, vastly upgrading our electrical vehicle infrastructure and are planning to introduce fines for car drivers who idle on our streets.”