Hounslow Council has been accused of "compulsively giving away" green spaces for development, adding to potentially lethal air pollution.

The charge was levelled by Green Party members as they teamed up with local residents to install new monitors to measure levels of toxic nitrogen dioxide in the borough.

It was strongly contested by the council, which defended its record on the environment and transport improvements.

A dozen of the air quality monitors were placed along the A4 Great West Road last Thursday (March 3) from Sutton Court Road in Chiswick to the GlaxoSmithKline building in Brentford.

They will remain there for a month before being sent for analysis at University College London, as part of the Mapping for Change citizen science project.

Green Party members Andree Frieze and Shahrar Ali at the launch of new air pollution monitors in Hounslow

Andree Frieze, Green Party South West London candidate for the London Assembly, said: "Hounslow has been a car friendly borough for years, it is on Heathrow's flight path, it is compulsively giving away parks and green spaces to development and lacks investment on rail and cycling.

"It is no surprise the air quality is so bad on traffic saturated roads to central London and Heathrow.

'It is no surprise the air quality is so bad'

"Most European capitals have cleaned their public transport fleets and London is lagging behind, we need action now, and only the Green Party can clean up London's public transport by 2020."

Deputy council leader Amrit Mann, who is also cabinet member for the environment, claimed the council was working hard to reduce traffic on the borough's roads and told getwestlondon development in parks was only considered in "exceptional circumstances".

"The council is proactively working to improve public transport, walking and cycling infrastructure to encourage and make it easier for people to reduce their reliance on cars," he said.

"We will continue this work and will lobby hard for the necessary improvements to public transport which can secure the growth of high quality jobs in the borough, as well as reduce congestion and improve air quality.

"Development in parks is only considered in exceptional circumstances and only as part of plans that local residents and park users have been consulted about.

'Development in parks only considered in exceptional circumstances'

"In these instances, money from developments can be reinvested in parks. More than £1m has recently been secured from planning developments and is being reinvested in parks and open spaces."

He cited examples including the Beat the Street initiative, in which schoolchildren compete to gain points by walking or cycling; recent improvements to cycling and walking routes in Hounslow town centre; a major trial of electric car charging points ; and a multi-million pound investment planned in partnership with TfL on the cycle route along the A315 between Hounslow and Hamersmith

The monitors were placed along a stretch of the road known as the Golden Mile, where Hounslow Council envisages nearly 1,600 homes and new offices for up to 30,000 workers being created.

The Green Party is concerned about the impact of such large-scale development on air quality in the area, where previous tests showed levels of toxic pollutants already significantly exceeded EU limits.

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The House of Commons estimates the annual price tag of air pollution in the UK as £8bn-20bn, including the cost to the NHS and fines for breaching EU thresholds.

Deputy Green Party leader Shahrar Ali, who also attended the launch of the monitors, said: "Kids, commuters and residents in London are breathing terrible air. London needs to stop ignoring the World Health Organisation's guidelines and act now.

"We do not need another London mayor and Assembly that prioritises cars. Instead, we need to prioritise public transport, greenscapes and cycling."