Asthma UK community forum

Increase in Asthma and the Reduction of Trees

Hello and Thanks for having me as a member of your forum.

I was walking in my local park the other day and to my absolute horror I discoverd that there was a great big digger up-rooting the trees that had been there for ten years or more.

They are going to build another retailed park which we don't need, because that will bring in more cars, more cars equals more fumes.

Trees on the other hand need oxygen just like us to survive, therefore it got me thinking could there be a possible link with the demise of the trees and the increase in Asthma cases? What do other people think? If you send me your Ideas I can perhaps to research into this and send it to the BMA.

11 Replies

Hello and welcome to the AUK forum.

I don't think there is a direct link between tree loss and the increase of asthma as such. ( there may be some tentative links....) The only link I can see is the increase in traffic pollution because of the new retail park but that would be localised and even if new trees were planted the traffic effect would still be there.

For some asthmatics such as myself trees in spring can increase our asthma symptoms as we are allergic to tree pollens. Trees are wind pollinated and thus produce a lot of airborn pollen.

However, I would not want to see the loss of any tree except if it is causing a health & safety issue eg old, infected & loose branches that could fall off and demolish someone!

Trees actually take in carbon dioxide during the day and give out oxygen via photosynthesis and are therefore part of the carbon cycle as part of the carbon sink. One massive carbon sink is the Amazon! At night trees do take in a bit of oxygen as they are unable to photosynthesise at night ( no sun!)

I know as well as many other people that there is an increase in carbon dioxide in the atmosphere which creates the greenhouse effect but I am not sure if there has been much of a variation in the last few million years in the amound of oxygen available - currently around 21% of the air we breathe.

Unfortunately only trees with a 'TPO or Tree protection order' , or ancient woodland status, or and area with SSSI status on them can be reprieved from the digger (or not in the case of Stanted!!!). Trees often planted in urban areas in the past have often not been native and have very little protection unfortunately. I don't like to see the destruction of trees whatever unless they are dangerous or becoming a nuisance.

Hope this is some food for thought




Just a quick qu on this, don't trees take in oxygen all of the time, because they must need to respire all of the time, it's just that in the day they produce more oxygen than they take in, due to photosynthesis, so there is a net output of oxygen but they always take it in?

Claire xx


thanks everyone

I was getting a bit carried away, I forgot some Asthmatics are allergic to trees. worth a try thou.


Yes, claire you are right! - got side tracked .................

Plants do respire all the time but during the day they take in more CO2.

Oxygen in the air can actually inhibit photosynthesis but with sunlight photosynthesis and the intake of CO2 overtakes the O2 intake.

When Photosynthesis developed, the amount of O2 was a lot lower.

Higher levels of CO2 in the air promotes plant growth - I did experiments many years ago in solar domes looking at the increases in CO2 and temperature on plants. (New Zealand Willowherb - a cute small creeping invader) It grew happily in normal parameters, grew a lot more in elevated CO2 but was a bit stressed in Higher temps!

Sorry for the biology lesson!



I remember reading that hospitals used to remove plants and flowers from patients' rooms at night, as it was believed that the plants respiring would deplete the levels of oxygen in the air, and be detrimental to the patients in the room. I believe it was shown, though, that it doesn't in fact make any significant difference to oxygen levels in the air to have flowers in the room.

There are also stories that periodically go round about oxygen levels being depleted in various places around the world - they're also a bit of a fallacy. Oxygen levels all over the world remain at 21% at sea level.

As far as I'm aware, there's no link between destroying trees and increased levels of asthma, although it has to be said that the exact reasons for the increase in asthma haven't been fully determined.

Em H


Lime Trees and asthma

Is it possible for someone to tell me whether there are health problems with Lime Trees? Specifically, I would like to know if Lime Trees can cause, aggravate, or otherwise effect asthma sufferers. The reason I ask is that close to us there is a row of five or six mature Lime Trees, all in good health. Each tree reaches a height of about 50ft. These trees are situated near the back gardens of some of the houses in the street where we live, and screen us from a car park. One (only one) neighbour has complained to the owners of the land on which they are growing, saying they affect her husband's asthma. She has continually complained to the land owner. My wife suffers from asthma, and she is specifically allergic to Aspergillis, and she does not appear to be adversely affected by the Lime Trees.

The owners of the trees have written to all the residents in the street to ask their views on the subject, with the view to considering their removal. My wife and I would prefer to have the trees remain in situ, but our response will take into consideration any adverse effect that the Lime Trees may cause or contribute to.

We have been asked to respond by the end of February at the latest, and we would appreciate any information anyone can provide us with in order to make our minds up as to whether we would support the removal of the trees or recommend they are left in situ.

Edward and Sheila Schleising.


I would suggest that the person who states the lime trees are affecting their asthma get an allergy test to tree pollen though lime trees don't flower untill july and I think they may be insect pollinated, if that is the case, then there won't be much pollen released. Lime trees aren't mentioned in Hayfever pollen calenders either.

The trees would only affect them in July.

Ask them when the trees affect them, but don't tell them that they flower in July and see what they say. If they say spring or all year, then the limes are inocent!

I will try to find out more if you like and have time.



The problem from Lime trees is not the pollen but from the droppings / muck given off with regards to the aphids that live on the tree. It is this that increases problems with Asthma not the tree itself.


Asthma and Lime Trees

Thanks for your info Kate. I am now informed by other residents in the street that both the resident complaining about the trees, and her husband, smoke. I used to smoke, but gave up when I became aware of the effect it had on my wife. That was in 1971. We married in 1969 and are due to celebrate our 40th wedding anniversary on 15th February. I sometimes wonder if my wife would still be alive if I had not given up smoking.

I would welcome any more info you and/or others may have on any Lime Tree/Asthma connection.



Asthma and trees

I recently had the need to find out if asthma was caused or aggravated by Lime Trees. During my investigation I came across the information below:

""A Columbia University study, published in the

Journal of Epidemiology and Community

Health in May 2008, concluded that city blocks

boasting plenty of trees are not only more

pleasing to the eye, they may be healthier for

children's lungs.

Dr Gina S. Lovasi and colleagues found that 4

and 5-year-olds living along New York City’s

greenest streets were less likely to have

asthma than young children living in sparsely

planted neighbourhoods.

As the density of trees in a neighbourhood

rose, asthma prevalence fell, even after the

researchers accounted for the percentage of

residents living below the poverty line, a

neighbourhood's proximity to pollution sources

such as busy lorry routes, and other relevant


The Columbia university study suggests that the presence of trees benefits and/or reduces asthma in children. Children eventually become adults, so there would be a reduction in adults having asthma. Turning the indications of this study round to your question, it means that lack of trees can, in fact, cause or aggravate asthma.

I hope this helps you in your research. You can find more info on asthma from Columbia University on the internet. Once on their website, just put ""asthma"" into their search box and you will find more info. You may even be able to contact the person named in the study and get an update on the article I've printed.

I hope this helps.



I seem to recall hearing or reading somewhere of a theory that trees in their repiration process act as an air filter taking out pollutants?


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