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Comment by alecco | Hacker News Reader

Zero mention of the problem of hormones (contraception), antibiotics, and a lot of random things coming with human urine. It's very hard to get rid of those, last time I checked the best way was to let it break over YEARS. This is not viable at large scale. (My family used to be farmers)

And note the animal waste from feedlots is quite toxic and yet it's being used at scale without proper processing in some unscrupulous corporate farms. Or they dump it in "swine lagoons".

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> Zero mention of the problem of hormones

This isn't true.

TFA links to a page that points out hormone uptake wasn't found in plant tissue and that the uptake of drugs like caffeine and tylenol are at tiny fractions of a minimum effective dose.

For caffeine this should be somewhat expected - it's a chemical produced as an insecticide by at least 3 or four completely unrelated families of plants.

I doubt it's a major issue, but some chemicals will build up over time if I recall correctly and should be removed from the cycle altogether, if possible.

But I also like to think (and this is all unscientific gut feeling) that processing it in compost and exposing it to the elements and UV sunlight helps break down everything. Entropy, or my probable misunderstanding thereof.

https://richearthinstitute.org/how-it-works/

There is a treatment section on their website. They list details about pharmaceuticals in their guide as well.

https://richearthinstitute.org/wp-content/uploads/2024/03/Ur...

>While there are some pharmaceutical compounds detectable in crop tissue, the levels are extremely small–in the nanogram per gram (or parts per billion) range

I was somewhat skeptical about this given all the headline I've seen about birth control causing hormones to be in the water supply, but it checks out.

https://pubmed.ncbi.nlm.nih.gov/20977246/

>This paper reviews the literature regarding various sources of estrogens, in surface, source and drinking water, with an emphasis on the active molecule that comes from OCs. It includes discussion of the various agricultural, industrial, and municipal sources and outlines the contributions of estrogenic chemicals to the estrogenicity of waterways and estimates that the risk of exposure to synthetic estrogens in drinking water on human health is negligible

Are those taken up by plants? I think there’s even some debate around the effects of using treated wood for raised vegetable gardens. Last when I looked into it, I think there was some elevated arsenic in plants and the advice was to plant a few inches away from the edges of the bed since the exposure drops off.

>I think there’s even some debate around the effects of using treated wood for raised vegetable gardens

It's not a debate or the matter or health or organic wonks. "pressure treated wood" is treated with a compound of arsenic. Arsenic is quite toxic and readily leaches into the ground and your garden. Like you really shouldn't touch pressure treated wood, you should wear gloves and wash your hands after. It is banned in the US for construction of residential things which come into contact with humans and totally banned in several countries.

Leave pressure treated wood away from your food... a few inches planting away from it isn't enough.

> "pressure treated wood" is treated with a compound of arsenic.

It depends--I am assuming you're referring to chromated copper arsenate [0] (CCA), which has been widely phased out in favor of other treatments, like copper azole [1].

I wouldn't go and build a raised garden bed out of copper azole treated wood either, but I also wouldn't be surprised if the leached copper etc. is quite a bit safer than CCA.

0: https://en.wikipedia.org/wiki/Chromated_copper_arsenate

1: https://en.wikipedia.org/wiki/Wood_preservation#Copper_azole

CCA is restricted in some residential applications, but it is still very much for sale for industrial and some structural uses. Most pressure treated you will find won't have it any more, but not all.

https://www.menards.com/main/find.html?find=CCA+treated.&ski...

Chromated arsenic treatment was banned in pressure treated wood in 2003. Pressure treatment with less toxic chemicals is not banned.

https://www.epa.gov/ingredients-used-pesticide-products/over...

You can still buy it, you're just not supposed to use CCA treated wood for a list of residential uses.

Eh, uv diods? You lower them in, vibrate and rotate the material, degrade it? Standard processing step