Council told no health benefits planting trees

COVENTRY City Council has been told there are no health benefits for planting trees.

The topic of green infrastructure was discussed during a meeting with the cabinet member for communities and housing Councillor Ed Ruane on Monday.

Cllr Ruane was told the council submitted a funding bid for a green infrastructure scheme in Ball Hill in a bid to tackle high levels of air pollution, but this was rejected due to a lack of evidence pointing towards the benefit of trees.

Karen Lees, from Public Health, said the Department for Environment, Food and Rural Affairs (DEFRA) told them there was “mixed evidence” trees could improve air quality.

But Cllr Ruane questioned if this meant trees have a neutral effect on air quality, adding: “It is not going to add to the toxicity is it?”

Ms Lees said: “It is more that it is unproven, that was DEFRA’s view. We were advised by DEFRA that there was not the evidence to show it was beneficial.”

The need to improve the air quality in Coventry is of particular importance as the city is one of 28 towns and cities in the UK forecast to exceed legal NO2 limits in 2020. Yet Cllr Ruane questioned if the green infrastructure funding bid was turned down for Ball Hill, would the council be successful in funding bids for projects elsewhere.

He also cited a scheme in Mexico City, where authorities have attempted to tackle pollution by launching a project to plant 18 million trees two years ago.

He added: “The element of greening our city is because of the health benefits it brings and now they are saying there is no evidence for that.

“I am curious as to why they spent so much money doing it in Mexico City if our evidence is that it does not do anything.”

At a meeting back in August there was some suggestion that trees could actually be bad for air pollution. Officers advised that planting trees could have some benefits, but it depended how they were used and warned that in certain circumstances they could create problems of their own.

While some particles will stick to trees and certain gases will be absorbed by the leaves, councillors were told that recent reports had shown dense foliage could act as a “physical barrier” which trapped the harmful emissions at ground level.

The Office for National Statistics (ONS) study found that while trees did draw in substances such as sulphur dioxide, they did not have a tangible impact on concentrations of nitrogen dioxide in the atmosphere.

Data from 2015 estimates that around 1.4 million tonnes of air pollutants were removed from the atmosphere because of greenery, although this figure is dwarfed by the level of emissions being produced. Summarising the situation, the report said: “Even though vegetation will not solve the whole issue of air quality in the UK, and in some cases vegetation can have adverse effects on air quality, the service of air pollution absorption by vegetation is an important one.”