3 ms·

I think WHO indiscriminately spraying DDT is bigger news. It's what killed the original cats in the first place, and how much damage did it do to humans? It was

I think WHO indiscriminately spraying DDT is bigger news. It's what killed the original cats in the first place, and how much damage did it do to humans? It was a different time...

marginalia_nu 3y ago
The notion that toxins accumulate in greater concentrations the farther up you go in the food chain, eventually ending up in apex predators like cats, eagles, and so on; seems to have not been well understood at the time.
toast0 3y ago
It's still acceptable to use DDT as an insecticide for malaria control (in areas where mosquitos are not DDT resistant). There are certainly negative effects on other wildlife and humans from that use, but specifically on humans, I think there's a risk/benefit analysis that at a population level, reduced malaria outweights negatives from DDT exposure. It's probably helpful to use targetted spraying rather than indiscriminate spraying, but DDT is a powerful insecticide and it's going to have broad effects on wherever it's sprayed.
joecool1029 3y ago
>I think WHO indiscriminately spraying DDT is bigger news. When DDT was first introduced they did studies on cats, humans, dogs. It can kill a cat, but the dose needs to be extremely high, reported as 300mg/kg. (one of the sources on it: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2057789/pdf/brmedj03890-0003.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2057789/pdf/brm... ) You'll note the article mentioned dieldrin was used briefly. Less than 25mg/kg is enough to kill a cat: https://www.sciencedirect.com/science/article/abs/pii/0041008X67901007 https://www.sciencedirect.com/science/article/abs/pii/004100... . It also bioaccumulates and is extremely persistent. DDT was sprayed consistently because it was known to be fairly safe for mammals, cats have a shit liver for breaking down most pesticides but I still think the dieldrin is the real culprit here since there's documentation of its use and it's way nastier to mammals. EDIT: Yeah, consistent with what I was thinking, I looked for measurements of the various pesticide residues in the environment around Malaysia: https://enviro2.doe.gov.my/ekmc/wp-content/uploads/2016/08/1384783396-1-s2.0-S1474817707070143-main.pdf https://enviro2.doe.gov.my/ekmc/wp-content/uploads/2016/08/1... (spoiler: aldrin and dieldrin were often found in higher concentrations than DDT and as mentioned before have much greater toxicity)
- throwaway290 3y ago
  It's not about killing a human but causing other issues. Xenoestrogens accumulate and as you eat something that grew up around it you accumulate some of that too. For older people it may be fine but at younger ages they wreak havoc, accelerate sexual development but at the same time cause fertility issues like reduced sperm counts (https://en.wikipedia.org/wiki/Xenoestrogen#Mechanism_of_action https://en.wikipedia.org/wiki/Xenoestrogen#Mechanism_of_acti...). Sure at the time some of these studies maybe were unknown but I think it's always worth asking yourself if you spray some new chemical that you know is great at killing some harmful wildlife around people in a faraway country, will it also harm people in that country for generations.

I think WHO indiscriminately spraying DDT is bigger news. It's what killed the original cats in the first place, and how much damage did it do to humans? It was a different time...

marginalia_nu 3y ago

The notion that toxins accumulate in greater concentrations the farther up you go in the food chain, eventually ending up in apex predators like cats, eagles, and so on; seems to have not been well understood at the time.

toast0 3y ago

It's still acceptable to use DDT as an insecticide for malaria control (in areas where mosquitos are not DDT resistant). There are certainly negative effects on other wildlife and humans from that use, but specifically on humans, I think there's a risk/benefit analysis that at a population level, reduced malaria outweights negatives from DDT exposure. It's probably helpful to use targetted spraying rather than indiscriminate spraying, but DDT is a powerful insecticide and it's going to have broad effects on wherever it's sprayed.

joecool1029 3y ago

>I think WHO indiscriminately spraying DDT is bigger news. When DDT was first introduced they did studies on cats, humans, dogs. It can kill a cat, but the dose needs to be extremely high, reported as 300mg/kg. (one of the sources on it: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2057789/pdf/brmedj03890-0003.pdf https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2057789/pdf/brm... ) You'll note the article mentioned dieldrin was used briefly. Less than 25mg/kg is enough to kill a cat: https://www.sciencedirect.com/science/article/abs/pii/0041008X67901007 https://www.sciencedirect.com/science/article/abs/pii/004100... . It also bioaccumulates and is extremely persistent. DDT was sprayed consistently because it was known to be fairly safe for mammals, cats have a shit liver for breaking down most pesticides but I still think the dieldrin is the real culprit here since there's documentation of its use and it's way nastier to mammals. EDIT: Yeah, consistent with what I was thinking, I looked for measurements of the various pesticide residues in the environment around Malaysia: https://enviro2.doe.gov.my/ekmc/wp-content/uploads/2016/08/1384783396-1-s2.0-S1474817707070143-main.pdf https://enviro2.doe.gov.my/ekmc/wp-content/uploads/2016/08/1... (spoiler: aldrin and dieldrin were often found in higher concentrations than DDT and as mentioned before have much greater toxicity)

throwaway290 3y ago
It's not about killing a human but causing other issues. Xenoestrogens accumulate and as you eat something that grew up around it you accumulate some of that too. For older people it may be fine but at younger ages they wreak havoc, accelerate sexual development but at the same time cause fertility issues like reduced sperm counts (https://en.wikipedia.org/wiki/Xenoestrogen#Mechanism_of_action https://en.wikipedia.org/wiki/Xenoestrogen#Mechanism_of_acti...). Sure at the time some of these studies maybe were unknown but I think it's always worth asking yourself if you spray some new chemical that you know is great at killing some harmful wildlife around people in a faraway country, will it also harm people in that country for generations.