I have become aware that within some parts of the ”Green” community that uranium is being regarded as public enemy number one. I think that this attention to uranium started around about the time of the first gulf war when a series of friendly fire events (fraternicide) where allied personnel were shot using depleted uranium antiarmour ammunition.
One of the ideas which is circulating is that uranium has a strong ability to bind to DNA and it thus causes DNA damage. I am well aware that for years that uranium has been used as a stain in electron microscopy work to allow DNA to be seen with greater ease. But this fact alone does not mean that uranium will stick to DNA and thus cause the DNA damage which leads to cancer, birth defects and the rest of the horror show which some people claim is caused by the use of “DU”.
I would like to apply some common sense and critical thinking to the question of uranium and health. Firstly there is this question of “does uranium exert a harmful effect through binding to DNA ?”, this is an important question as some metals such as chromium and platinum can bind directly to the nitrogen DNA bases and thus damage the DNA.
Now I will not pretend to be all knowing, but I do know something about uranium chemistry. If we were to assume that the human body has two compartments for uranium. That is the “free” uranium and the uranium bonded to DNA then using a binding constant for uranium to DNA we could get an answer using the following simple equation. (Langmuir isotherm equation)
Θ = k [U][DNA] / (1 + k [U][DNA]) = k [U] / (1 + k [U])
This weird looking thing Θ is the fraction of the DNA which has uranium bonded to it.
However in real life a range of molecules other than DNA can bind to uranium, a classic example is carbonate. As all living humans are making carbon dioxide inside them then I think it is safe to assume that we should consider the binding of carbonate to uranium in any model of uranium in humans.
The new equations are going to be a lot more complex.
I am sure that our new value of Θ which takes into account the carbonate binding of DNA will now be lower. I have to say that this carbonate binding does make uranium look much less scary from the DNA binding point of view but we are not done with uranium yet. I may well write another blog post on uranium soon.