
Hello all
I wonder if anybody could answer my question?
I have an apple tree in the back garden of a house which is on a busy main road (A40 Shepherds Bush, one of the main arteries into central London - we are talking more or less constant heavy traffic). I am wondering if anybody could tell me if it is possible for toxicity from traffic pollution to find it's way into the fruit?
I don't know what variety the tree is but it gives lots of apples which are good for juicing and cooking, just want to check that they are safe!
Would be most grateful for any advice.
Thanks
Richard
With absolutely no scientific basis for it, I'm going to guess "yes, pollutants find their way in" Some of that nastiness settles onto and into the soil, and some of it is probably taken up by the tree. How much of it dissolves and is taken up? Not a clue. I'm also going to guess that you'll take in far more pollutants by breathing the air (which the poor tree is valiantly cleaning) than you will by eating the fruit.
I hope one of our more scientific members will offer a more knowledgeable answer.
mh

The short answer would in all probability be "yes" because everything can be polluted and heavy traffic is a contributor.
The more educated answer is what are tolerable levels of pollution? How many parts per million of which elements or chemicals are sufficiently toxic as to cause a problem. Forgive me for being cynical but biases are tremendously important and a person can pick and choose certain statistics to support one position and another person can find other statistics to support a different position.
When I worked with an Environmental Health agency I actually became somewhat cynical about how certain elements would unwittingly conspire to play on people's fears in order to justify the very agency I worked for and I came to the conclusion most environmental fears were exaggerated.
However, someone else could come up with the conclusion that the costs are justified to do everything possible to have an absolutely clean product. Different person. Different bias.
When I picked blackberries for Nanci's Dairy in Eugene, Oregon years ago I was told (I think by the dairy) that they preferred to receive the wild Himalayan blackberries from vines that were not near a major arterial roadway but more off the beaten path. So, clearly, the folk wisdom (or business wisdom) is to get it off the beaten path.
But would I eat your apple near the highway and not worry about it? Absolutely......and that is where the argument begins.

There have been specific studies done on this. I used the information when I decided to move. Here's the skinny: if you live within 400 meters of a freeway, you might not want to eat the edibles on your property. You have about 8 times the chance of cancer, heart attack and many other diseases. Farther away, it drops off until it is negligible. A freeway is not the same as a busy street, because of the sheer volume of the traffic. I just googled it. I think it was about San Diego but the ideas apply across the board.
John S
PDX OR

Wow, thanks John, thats really specific, helpful information.
The road I'm talking about is more akin to a freeway than an ordinary busy road and I think the tree itself is within 400 metres although the house is in between.
I will see if I can find the study online (just what I hoped and anticipated that research would already have been carried out). I think I'll be leaving the fruit well alone!
Many thanks again.

I have to agree with John. We live near the busy A1 in northumberland. My fruit trees and bushes are covered by a fine layer of pollution. I'm not sure about the 8 times more likely to get cancer, but I'm sure the smog and petrol fumes are doing my fruit no good at all. I always wash them carefully before eating and I always remove the skins!!!

This is a summary of some studies. It is different than what I looked at earlier, but the conclusions are similar:
http://www.scpcs.ucla.edu/news.....reeway.pdf
Here's another:
http://www.sfdph.org/dph/EH/Ai.....111907.pdf
Here's another:
http://www.ehjournal.net/content/6/1/23
John S
PDX OR

Thanks, John, for your research. I don't deny that freeways provide pollutants, but....sensing your open nature, I don't think you will mind if I raise a few questions for a slightly different take:
1. Your studies dealt a lot with pollutants and what we inhale and the consequent lung or heart problems related to that. This is not to be confused with pollutants that might actually find their way on fruit. I would think that fruit, particularly if washed, would be pretty good. For example, a carrot in the ground is exposed to all kinds of things in the ground that might sound "bad" if taken out of context and if spoken of individually....but when washed, that carrot is free of basically anything that is in the ground.
The only way to know is to see exactly what chemicals remain on washed fruit and then to see if the parts per million or parts per billion are of any significance.
2. Even for respiratory problems, there needs to be some context. For example, if there is a correlation between lung problems and proximity to a freeway, what is the relative danger level? Smoking may be 1,000 times more dangerous and second hand smoke 10 times more dangerous than living near a freeway.
To continue on this thought: One of your studies suggested "Approximately 11% of US households are located within 100 meters of 4-lane highways" and yet another study suggested you need to be at least 300 meters from the freeway to be basically free of any specific effects. From this one might think that at least 11% of households are at risk.
But are they? If the risk of pollutants to the lungs is very very small in comparison to other risks to the lungs, then I think it could be argued that buying a house near the freeway is much, much better for your health if you can get away with paying $10,000 less of your work, sweat and lifeblood to have purchased that house.......and those risks are really basically just to your lungs and not to the food you eat there, anyway.
If you see what I mean....I hope I don't come across as being too argumentative......if I am naiive, I can stand to be corrected.

Hi Don,
I think you bring up some good points. Some of the studies were talking about the effects of pollution on produce, and some were talking about the effects of pollution on people. I think they are two separate factors. I do think that it is very possible, but not certain that wiping off/washing produce could limit damage. It is hard to imagine that someone who smokes can with a serious face say that they are terribly concerned about their health. Smoking is something I can control easily. If one lives near a freeway, it's hard to not breathe. The nature of science is that we are gathering more data, and it seems to point in one direction here. At the same time, we only get one life, and we have to decide what we think is happening because our life is definitely happening to us every day. If we wait until more data comes, perhaps we are waiting until we get that highly probable cancer/heart disease etc, and then it is too late.
John S
PDX OR

[quote="DonRicks":b4426mqw] I would think that fruit, particularly if washed, would be pretty good. For example, a carrot in the ground is exposed to all kinds of things in the ground that might sound "bad" if taken out of context and if spoken of individually....but when washed, that carrot is free of basically anything that is in the ground.
The only way to know is to see exactly what chemicals remain on washed fruit and then to see if the parts per million or parts per billion are of any significance.[/quote:b4426mqw]
I'm not intending to be argumentative either, and my comments should not be taken as any position of the health risks being discussed. But what we should all remember is that pollutants, and anything we may intentionally apply to our plants, will only be limited to affecting surfaces IF their molecular size is larger than what the surface tissues will allow to pass through. If we don't know the molecular size and the tissue limits, we should assume that the molecules do end up in the plant parts we eat. Of course we won't know the peak concentrations or the concentration gradients, and reactions in the plants may result in those molecules becoming different molecules.

I suppose, as has been mentioned by previous posters, on a bit of perspective. If everything else you eat comes pre-packaged from the supermarket and you smoked 40 a day and you also used cleaning chemicals etc as if they were going out of fashion, I daresay a bit of polluted apple would make little difference to you. However I'm cynical of all these cancer studies, because I think there is too much variation in people's lifestyles to draw a comparison. Also we'd never acheive anything in life and wouldn't enjoy it if we folllowed all the health scares anyway.
I personally would eat the apples (maybe after washing them first!).
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