Item — HN Reader

So assessments of safety of a chemical aren't hard science. They are statistical judgment calls (often based on things like giving a much, much higher dose to a rodent and looking for short-term effects).

And the reason that is is because there's no affordable, moral way to give 100,000 farmers [nor consumers] a small dose of a product for 20 years before declaring it safe. So the system guesses, and it guesses wrong, often erring against the side of caution in the US (it's actually quite shocking how many pesticides later get revoked after approval).

Europe takes a more "precautionary principle" approach. In those cases of ambiguity (which is most things approved and not), they err to the side of caution.

Notice how this claim here is again shifting the burden to the victims (their research doesn't meet standard X, allegedly). Absence of evidence isn't evidence of absence.

4 comments

IMO the FDA should do a better job at helping the populace distinguish between these two:

1) Evidence for the null hypothesis (there are enough studies with sufficient statistical power to determine that product likely does not cause harm at a >95% CI).

2) There is no evidence that it is unsafe. (nor that it is safe).

The problem is #2 sounds a lot stronger and often better than #1 when put into English. There must be some easy to understand way to do it, IE an 'insufficient testing' vs. 'tested' label/website or something.

> assessments of safety of a chemical aren't hard science

These are still data. I'm curious for the contexts that lead other countries to actively ban the substance.

If it simply hasn't been approved in other countries, one can't use that information to infer about its safety.

Because of its high toxicity, the European Union withdrew paraquat from its market in July 2007 [1]

So it's clearly poisonous to humans in high doses, I guess the argument is that perhaps the smaller doses exposed to farmers may not lead to sufficient ingestion to cause harm. The parkinsons seems like pretty clear evidence against that.

> If it simply hasn't been approved in other countries, one can't use that information to infer about its safety.

I don't know why you're trying to defend this with counterfactuals/hypotheticals instead of just googling. Feels like you're bending over backward here.

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC3657034/

> don't know why you're trying to defend this with counterfactuals/hypotheticals instead of just googling

Genuinely appreciate the source. I wasn't finding it on my own, at least not with the nexus to the EU's decision.

Shouldn't most chemicals be assumed unsafe until proven otherwise? How many chemicals have we produced in a lab that have no harmful effects? Even medicine is bad for you, it's just better than the disease it's meant to treat. I don't know why we'd treat something designed to kill animals as safe for humans without studies showing that it's not harmful. (Well I do know why, but I don't know why voters go along with it.)

Literally everything is "chemicals".

And when we're talking about things in this realm, the general saying is "The dose makes the poison"... Water will kill you if you drink enough of it.

And we do have all sorts of studies showing that harm from these substances isn't immediately apparent (they all have safety sheets, and maximum safe exposure levels) . What we're missing, mainly because it's just incredibly hard to ethically source, is long term studies.

So the question you're really asking is "what's your tolerance to risk?". I think it's fine to have different governing bodies take different stances on that scale. What's less fine is failure to act on information because of profit motives.

Long story short - this isn't so simple. You bathe in chemicals all day every day.

I daresay that the issue is less about "chemicals" and more about "new chemicals". If a substance already exists in nature and has been in use for a long time, then it's reasonable to take the position that it is probably within harm limits. If it's a newly synthesised/extracted substance, then it should be subject to reasonable testing.

Also, if a chemical is known to be toxic, then rigorous testing should be performed before allowing it to be widely distributed and used.

> If a substance already exists in nature and has been in use for a long time, then it's reasonable to take the position that it is probably within harm limits.

Reasonable, but wrong.

Simple case: Did you know that occupational sawdust exposure is strongly associated with cancer in the paranasal sinuses and nasal cavity?

There's also some pretty compelling evidence that coronavirus's (so common cold & flu) are associated with dementia/Alzheimer's.

Alcohol increases cancer rate more than some of the "chemicals" people will complain about. So does Bacon. So does sunlight.

All of which have been floating around in Human contact for a LONG time.

Again - we do a pretty good job at filtering out the stuff that's fast acting and harmful. It's just really difficult to tease out information that requires long term monitoring and involves small/moderate increases in risk.

Think about how long it took us to figure out that lead exposure is really nasty. We used lead for thousands of years prior, and it's literally a base element.

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As for

> Also, if a chemical is known to be toxic, then rigorous testing should be performed before allowing it to be widely distributed and used.

No one is arguing otherwise, and normally large and expensive studies are done on short term harm (extensive animal testing). But you tell me how we can reasonably and ethically do longitudinal studies on large groups of humans to determine if a new substance is going to cause small/moderate cancer rate bumps over 50+ years?

This is just genuinely a difficult problem to address, and it's not simply like we can go "wait 50 years and see"! Because usually we're trying to use these things to address existing problems. Ex - pesticides and fertilizers might still be net positives even with the cancer risk - do we avoid them and let people starve today? Or feed everyone now and have a 10% bump in cancer rates 50 years later? There's no golden ticket here.

>Shouldn't most chemicals be assumed unsafe until proven otherwise?

Of course not, that would be bad for capitalists. /s

The US is very capitalist and consumer based. They error on the side of “does it make money?” Or “will I lose money?”