Johnny Niamert wrote:What about dioxin content of paper?... composting large amounts of it can concentrate it.
Brett Andrzejewski wrote:...Good reference finds too.
This is the model I subscribe to fervently. Agri/ecology are sciences, and rely on specific metrics, so I'm always looking for those in new ideas and established practices. Makes the conversation easier, leaves less to question
"Without documentation, you're just another person with an opinion."
Rusty Shackleford wrote:A few weeks ago I was reading Slow Death by Rubber Duck by Rick Smith, Bruce Lourie
One troubling point they bring up is the prevalence of BPA in non-plastics. Given the popularity of cardboard mulching, and the essential nature of 'brown material' in vemicomposting, I thought I would share:
drake schutt wrote:...
Who even knows if plants uptake BPA? Or if it's bio-magnified up the food chain?
Many pharmaceutical and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs) are present in reclaimed water, leading to concerns of human health risks from the consumption of food crops irrigated with reclaimed water. This study evaluated the potential for plant uptake and accumulation of four commonly occurring PPCP/EDCs, i.e., bisphenol A (BPA), diclofenac sodium (DCL), naproxen (NPX), and 4-nonylphenol (NP), by lettuce (Lactuca sativa) and collards (Brassica oleracea) in hydroponic culture, using (14)C-labeled compounds. In both plant species, plant accumulation followed the order of BPA > NP > DCL > NPX and accumulation in roots was much greater than in leaves and stems. Concentrations of (14)C-PPCP/EDCs in plant tissues ranged from 0.22 ± 0.03 to 927 ± 213 ng/g, but nearly all (14)C-residue was non-extractable. PPCP/EDCs, particularly BPA and NP, were also extensively transformed in the nutrient solution. Dietary uptake of these PPCP/EDCs by humans was predicted to be negligible.
John Chater · University of California, Riverside ...
BPA is a relatively large (and nonpolar) molecule compared to the ions that plants typically take up (K+, N03-, Mg++, ect.), so I do not think that the plant will take up the BPA (which has two phenol groups in the structure), so there is theoretically no way for the soil's BPA to get into the crop. Which crops are you interested in?
Remember, all materials need to pass through the Casparian strip in order to make through the root's endodermis and into the vasculature. [emphasis mine]