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I don't know about lithium in compost, but in general, composting breaks down many pharmaceuticals (again, apart from certain chemo drugs). Composting does des

by Panino 5y ago

I don't know about lithium in compost, but in general, composting breaks down many pharmaceuticals (again, apart from certain chemo drugs). Composting does destroy some anti-cancer drugs like Salinomycin. PFCs may accumulate almost regardless, although I assume composting helps. After all, composting can break down gasoline, diesel, and TNT - though of course you shouldn't add them to a compost bin! Quoting The Humanure Handbook (4th edition) page 115: "About half the sewage sludge (biosolids) produced in the USA is applied to land, providing a significant opportunity for contaminants to enter soil systems and to bioaccumulate over time..." And page 117: "For example, brominated fire retardants were still found at almost eight thousand times higher concentrations than background concentrations in soil samples twenty years after the last application of biosolids. In another study, fifteen out of nineteen pharmaceutical drugs were still present in soil six months after being irrigated with contaminated wastewater." So PFC accumulation is already happening but not because of composting. It's happening because sewage sludge is being added to farm fields and new housing developments. This is part of why I cook with clay (in solar cooking) and stainless steel on the stovetop. That way my nutrient loop (eat, excrete, compost, grow more food) has the absolute minimum of PFCs and other contaminants. For more information, read chapter 10 of The Humanure Handbook (4th edition) by Joseph Jenkins.

hedgehog 5y ago
Lithium I picked as it's a heavy metal that wouldn't break down per se, though maybe the form it would exist in post-compost would be plenty benign. The sewage sludge issue I'm unfortunately aware of and have been following due to this case: https://www.mainepublic.org/environment-and-outdoors/2022-02-07/complete-crisis-as-pfas-discovery-upends-life-and-livelihood-of-young-maine-farming-family https://www.mainepublic.org/environment-and-outdoors/2022-02... In my area the majority of contamination is from firefighting foams, and I think in the Bay area there's also a lot in groundwater from semiconductor manufacturing. My understanding is the known way to remove PFCs from soil involves baking at very high temperatures (like 500C) which is impractical at any scale.
- scotty79 5y ago
  Lithium is not a heavy metal.
  - hedgehog 5y ago
    Hah, fair, it's actually light. I don't know to what degree it would get taken up by plants or other food organisms (chickens etc), but if it were then that could be a concern as it's a common medication and the net concentration could climb without removal.
netizen-936824 5y ago
These are all great points, however the issue with PFCs is that they are extremely nonreactive. Things like TNT, gasoline, and diesel are the exact opposite. Those compounds are reactive and quite easy to break apart. Even so, there must be some sort of either precaution or processing steps that can be taken to minimize PFC concentration, although I don't quite know what they might be.

by Panino 5y ago

hedgehog 5y ago

Lithium I picked as it's a heavy metal that wouldn't break down per se, though maybe the form it would exist in post-compost would be plenty benign. The sewage sludge issue I'm unfortunately aware of and have been following due to this case: https://www.mainepublic.org/environment-and-outdoors/2022-02-07/complete-crisis-as-pfas-discovery-upends-life-and-livelihood-of-young-maine-farming-family https://www.mainepublic.org/environment-and-outdoors/2022-02... In my area the majority of contamination is from firefighting foams, and I think in the Bay area there's also a lot in groundwater from semiconductor manufacturing. My understanding is the known way to remove PFCs from soil involves baking at very high temperatures (like 500C) which is impractical at any scale.

scotty79 5y ago
Lithium is not a heavy metal.
- hedgehog 5y ago
  Hah, fair, it's actually light. I don't know to what degree it would get taken up by plants or other food organisms (chickens etc), but if it were then that could be a concern as it's a common medication and the net concentration could climb without removal.

netizen-936824 5y ago

These are all great points, however the issue with PFCs is that they are extremely nonreactive. Things like TNT, gasoline, and diesel are the exact opposite. Those compounds are reactive and quite easy to break apart. Even so, there must be some sort of either precaution or processing steps that can be taken to minimize PFC concentration, although I don't quite know what they might be.