JustinCEO Topic

[JustinCEO]

Continuing discussion from Silent Spring - #19 by alanforr

@alanforr

@Elliot

For Carson, et al., the dosage level of DDT was irrelevant, as was the reality that alternative pesticides were equally toxic to other wildlife.

This is simply lying. Carson says in the book that dose matters and that toxicity levels vary and matter. Alternative pesticides were not all equally toxic to wildlife – some were much more toxic than DDT, as Carson says in the book (which doesn’t actually demonize DDT in particular).

As I understand that quote, you claimed that the article was wrong when it claimed that “For Carson, et al., the dosage level of DDT was irrelevant”. You also made other claims, but this is the particular claim I’m considering.

The Carson quote sez:

The individual exposed to DDT, for example, is almost certain to be exposed to other liver-damaging hydrocarbons, which are so widely used as solvents, paint removers, degreasing agents, dry-cleaning fluids, and anaesthetics. What then can be a ‘safe dose’ of DDT?

Carson is saying no dose is safe, so dose is irrelevant to safety.

Some more context around your quote from the book:

EDIT: THE BELOW QUOTE APPEARS TO BE A MISQUOTE. I AM LEAVING IT AS IS SO THE CONTEXT OF CRITICISM I RECEIVED BELOW IS CLEAR, BUT I AM PUTTING THIS WARNING UP SO AS NOT TO SPREAD A MISQUOTE.

An individual may have many different exposures to the same chemical. Arsenic is an example. It exists in the environment of every individual in many different guises: as an air pollutant, a contaminant of water, a pesticide residue on food, in medicines, cosmetics, wood preservatives, or as a coloring agent in paints and inks. It is quite possible that no one of these exposures alone would be sufficient to precipitate malignancy—yet any single supposedly ‘safe dose’ may be enough to tip the scales that are already loaded with other ‘safe doses’. Or again the harm may be done by two or more different carcinogens acting together, so that there is a summation of their effects. The individual exposed to DDT, for example, is almost certain to be exposed to other liver-damaging hydrocarbons, which are so widely used as solvents, paint removers, degreasing agents, dry-cleaning fluids, and anesthetics. What then can be a ‘safe dose’ of DDT?

I think Carson is expressing skepticism that there can be a safe dose of DDT in full context of the likely other potential things one is exposed to. I think maybe some people are reading her claim as a claim that there is no safe dose of DDT inherently - that even the tiniest possible amount of DDT is unsafe to humans, without considering the context of other things to which they are exposed. I think her language about “tip the scales” is key to interpreting her: she’s saying that DDT could push you above a critical threshold. It would have been clearer if she’d asked “What then can be a ‘safe dose’ of DDT [in this context]?”, but I think that’s what she was going for.