If you have read any of my other blogs then you will know that part of my new allotment is contaminated with benzo (a) pyrene.  It is a chemical that does not easily enter the food chain and I am being allowed to continue to grow on this area.  Most of this it is given over to sweet peas but I do have runner beans and pumpkins there as well.  It is a carcinogen so  I have been advised to make sure I wash my hands after working in this area. The dosages in the hot spots are worrying enough to cause the authorities to replace the soil to a depth of 60cm on this part of the allotment. 

How this chemical came to be on the allotments is a mystery.  It could have been there for years because it does not dissolve easily and is not washed away.   I am happy with the reassurances I have been given and I am carrying on growing.   It is not the ideal though. 

Now this colours my opinion of the new weed killer aminopyralid.  This weed killer is sprayed onto pasture and while it kills weeds, it does not kill grass.  Cows eat it and what goes in comes out the other end and eventually can land up on someones allotment as manure.  Aminopyralid can stay active for up to two years which means that the manure could affect allotment vegetables.  It seems from the allotment.uk forum that this is what is happening throughout the UK.   Now I thought I was safe because I only use horse manure from horses that live on a pristine field.  I would like to believe that their manure is uncontaminated.  However, chemicals like these have a way of squeezing themselves into the most unlikely of places. 

I am more of a biochemist than a chemist which means that I look at man made chemicals in a slightly different way.  Biochemists like to mash things up because they deal with very small quantities of naturally occurring chemicals.  They also deal in cascades - which means one very small amount of a chemical causes production of another small amount of chemical which then may go on to cause the production of a relatively big amount of a further chemical - or several different chemicals.  So in biology a small amount of a particular chemical can produce quite a big effect.  It only takes one molecule of a chemical or one photon of sunlight to cause cancer.  The only thing that higher concentrations do is make it more likely. 

We have been cheerfully spraying and dousing the environment with man made chemicals for years.  I did it myself.  In the 1960s lots of new pesticides and herbicides came onto the market.  However, it did not take long before a lot of gardeners started to question what effect these chemicals were having on our health.  I remember saying to myself what is happening to the soil animals?  With tiny amounts of chemicals having a relatively large affect on individual animals what effect did it have on the whole ecosystem?  Then came: “The Silent Spring”.     

I stopped using them and since then I have been trying to garden intelligently; using nature rather than fighting it. 

Now aminopyralid seems to be a wonder chemical that has absolutely no effect on the environment at all. Have a look at

 www.epa.gov/opprd001/factsheets/aminopyralid.pdf

Yet it is still effective in allotment manure after passing through a cow.  I would worry about it spreading throughout the environment. 

Are we going to have a “Flowerless Spring”.  It seems that we have not moved on very much from Rachel Carson.

This entry was posted on Sunday, July 6th, 2008 at 8:45 pm and is filed under aminopyuralid, benzo (a) pyrene. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.