are you sure abut the CCA? I was inder the firm impression they CCA tread it AFTER it has been milled.. CCA treating it before would mean they have to try to impregnate very large thicknesses of timber, where doing it after milling means smaller thicknesses and therefore a faster process.
The starting point here is planks, not logs. The planks have been treated and then htey are cut etc by this place where the sawdust is. Its not excatly a sawmill but its the only place around here where there's sawdust.
Again, I want to read it because I am not believing it for the same reasons stated above. I don't want a paper on anecdotal evidence, I want to read about the fungal roots taking up the antibiotic, then into the roots of the plant, and then into the plant tissues itself where it is transmitted to a person or animal. Anyone can claim an antibiotic is taken up by a plant, but is it broken down into something harmless? The root layer is so much more complex and vast then most people begin to have a clue about, and personally, I just don't see it happening.
Lots of CCA sawdust gets generated, think any joiner's workshop or building site where there is alot of woodwork.