I thank you too Paul, even if you have me worried about the sand added to the clay soil.
I am confused on it some what.
But confused or not - I am learning.
I also considered a couple of years ago to get some rubber to put on some black plastic - to keep weeds out between two narrow lines of shrubs. I did not know about the heavy metals. Cadmium is bad stuff!
Al - is the second most abundant element on the earth and in nature is always hooked to silicon which makes it pretty safe. Our bodies have ways of getting rid of it, but still in pure form without the silicon it might not be all that safe.. It is the main ingredient in vaccines and by- passing the digestive track it could be the reason that the autism is rising, Kawaskis, alziheimers, diabeties, ALS, MS, lupus, mitochondria cytopathy (energy cycle disrupted), thyroid problems; basically all the autoimmune diseases. That is how they make vaccines cheap. A little pathogen protein and a lot of Al will evoke a strong immune response.
I suppose if the rubber mulch was not up hill to something, rain that fell on it soaked into the ground, or mulching non food items - but basically it is really ugly too - isn't it?