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I make sure my own children do things like wash their hands before eating to limit their lead exposure, but I've also been reading up on this issue and keep fin

by ern 10y ago

I make sure my own children do things like wash their hands before eating to limit their lead exposure, but I've also been reading up on this issue and keep finding this sort of equivocation: This does not mean that children at this level are poisoned,” Dietrich says. “There are very few studies of low-level lead exposure, but there is nothing in the data that suggests that children will have negative impacts of short-term low-level exposure” over their lives. In fact, he notes, the 5 μg/dL figure was set because 97.5 percent of young children fall below it, not because blood lead levels at that threshold result in permanent harm https://www.scientificamerican.com/article/the-brains-of-flint-s-children-imperiled-by-lead-could-still-escape-damage/ https://www.scientificamerican.com/article/the-brains-of-fli... The evidence about low-level lead exposure and IQ seems far from definitive, and seems (to my amateur eye) to be full of unadjusted confounding, but I could be missing something.

nonbel 10y ago
>"the 5 μg/dL figure was set because 97.5 percent of young children fall below it, not because blood lead levels at that threshold result in permanent harm" What is the point of such definitions, and why does the medical community keep doing this type of thing? Using their method, 2.5% of young children will always be "exposed", no matter what is done. It is an automatically moving goalpost.
- ern 10y ago
  Indeed. I know the lead industry used to manipulate scientific research, in much the same way that the sugar industry has done in recent times, but that's no excuse for throwing scientific rigor away.
- deleted 10y ago
  [deleted]
- AbrahamParangi 10y ago
  Such definitions are useful because they result in useful safety factors when testing to find the actual threshold values is either impractical, immoral, or impossible. Consider: 1) Most children do not appear to suffer from lead-associated brain damage 2) Most children's lead levels fall below 5 μg/dL Therefore, while I do not know the level at which lead exposure results in brain damage, I can be safe in assuming that it is higher than 5 μg/dL. Moreover, since I know that most children fall below this level, it is not an overly difficult bar to achieve. So now we've got a regulation which we know is: 1) very achievable (in fact most of the population is already there) 2) almost certain to be on the safe side If you can recommend a better strategy, I'd like to hear it.
  - ern 10y ago
    Except the case of Flint, where in the article I linked to, the people who set the threshold of 5 have had to backtrack, and reassure parents that their children are not really "poisoned". The article also mentions concern over the stigma those kids will carry going forward of being labelled as "brain damaged". Such labelling isn't cost-free, and can wreak serious emotional damage on parents and children. But Edwards says that labeling children as “brain damaged” is also unjust. “Poisoning is obviously a loaded word,” he adds. “I’ve spoken to many parents in Flint, and I’m concerned because I don’t want children there defined by what happened to them https://www.scientificamerican.com/article/flint-s-lead-tainted-water-may-not-cause-permanent-brain-damage/ https://www.scientificamerican.com/article/flint-s-lead-tain... You will notice all the caveats in the article above, that are generally ignored in mainstream reporting of scientific studies around lead. If you can recommend a better strategy, I'd like to hear it. How about scientific studies that actually attempt to quantify the effects of lead, to determine an actual threshold of harm, handle confounding properly, and avoiding emotive and alarmist tropes when publicizing the results of those studies? Alarmism may be useful in the short term for getting action taken (and getting funding), but in the long-term, it will cause people to "tune out" or worse, to adopt anti-science attitudes (see current Global Warming skepticism).
    - AbrahamParangi 10y ago
      Your points about being careful about labeling are fair. I guess what I'm saying is this: Imagine that you have to set rules. The health and well-being of many people depend on you doing a good job setting those rules. You want to determine the most optimal rules but you have limited time and budget. You need to pick a number. You are lower-bounded by what is feasible and you don't know where your upper bound is. In this scenario, I think it is reasonable to pick a number which is near the lower bound and probably below the upper bound (aka what they did) rather than figuring out what the upper bound is. -Because honestly it may not be possible to reliably determine the upper bound (without literally poisoning people). Data is often scarce or bad when it comes to things which cannot (legally, ethically) be tested. Moreover consider the failure modes: If you pick an upper bound which is too low but still trivially attainable for most people (97.5%) then you inconvenience a very small minority of communities. If you pick an upper bound which is too high, you are literally personally responsible for causing brain damage in children. It's the sort of situation that the term 'better safe than sorry' was intended for.
mrfusion 10y ago
Why wash their hands? Where would they be coming into contact with lead?

by ern 10y ago

nonbel 10y ago

>"the 5 μg/dL figure was set because 97.5 percent of young children fall below it, not because blood lead levels at that threshold result in permanent harm" What is the point of such definitions, and why does the medical community keep doing this type of thing? Using their method, 2.5% of young children will always be "exposed", no matter what is done. It is an automatically moving goalpost.

ern 10y ago
Indeed. I know the lead industry used to manipulate scientific research, in much the same way that the sugar industry has done in recent times, but that's no excuse for throwing scientific rigor away.
deleted 10y ago
[deleted]
AbrahamParangi 10y ago
Such definitions are useful because they result in useful safety factors when testing to find the actual threshold values is either impractical, immoral, or impossible. Consider: 1) Most children do not appear to suffer from lead-associated brain damage 2) Most children's lead levels fall below 5 μg/dL Therefore, while I do not know the level at which lead exposure results in brain damage, I can be safe in assuming that it is higher than 5 μg/dL. Moreover, since I know that most children fall below this level, it is not an overly difficult bar to achieve. So now we've got a regulation which we know is: 1) very achievable (in fact most of the population is already there) 2) almost certain to be on the safe side If you can recommend a better strategy, I'd like to hear it.
- ern 10y ago
  Except the case of Flint, where in the article I linked to, the people who set the threshold of 5 have had to backtrack, and reassure parents that their children are not really "poisoned". The article also mentions concern over the stigma those kids will carry going forward of being labelled as "brain damaged". Such labelling isn't cost-free, and can wreak serious emotional damage on parents and children. But Edwards says that labeling children as “brain damaged” is also unjust. “Poisoning is obviously a loaded word,” he adds. “I’ve spoken to many parents in Flint, and I’m concerned because I don’t want children there defined by what happened to them https://www.scientificamerican.com/article/flint-s-lead-tainted-water-may-not-cause-permanent-brain-damage/ https://www.scientificamerican.com/article/flint-s-lead-tain... You will notice all the caveats in the article above, that are generally ignored in mainstream reporting of scientific studies around lead. If you can recommend a better strategy, I'd like to hear it. How about scientific studies that actually attempt to quantify the effects of lead, to determine an actual threshold of harm, handle confounding properly, and avoiding emotive and alarmist tropes when publicizing the results of those studies? Alarmism may be useful in the short term for getting action taken (and getting funding), but in the long-term, it will cause people to "tune out" or worse, to adopt anti-science attitudes (see current Global Warming skepticism).
  - AbrahamParangi 10y ago
    Your points about being careful about labeling are fair. I guess what I'm saying is this: Imagine that you have to set rules. The health and well-being of many people depend on you doing a good job setting those rules. You want to determine the most optimal rules but you have limited time and budget. You need to pick a number. You are lower-bounded by what is feasible and you don't know where your upper bound is. In this scenario, I think it is reasonable to pick a number which is near the lower bound and probably below the upper bound (aka what they did) rather than figuring out what the upper bound is. -Because honestly it may not be possible to reliably determine the upper bound (without literally poisoning people). Data is often scarce or bad when it comes to things which cannot (legally, ethically) be tested. Moreover consider the failure modes: If you pick an upper bound which is too low but still trivially attainable for most people (97.5%) then you inconvenience a very small minority of communities. If you pick an upper bound which is too high, you are literally personally responsible for causing brain damage in children. It's the sort of situation that the term 'better safe than sorry' was intended for.

mrfusion 10y ago

Why wash their hands? Where would they be coming into contact with lead?