
CDC considers lowering threshold level for lead exposure - finid
http://www.reuters.com/article/us-usa-lead-cdc-idUSKBN14J160
======
jwess
The water contamination crisis in Flint, MI has brought attention to the
dangers of lead exposure and aging infrastructure. The problems in Flint will
be expensive to fix, but many people are not aware of other "low hanging
fruit" in this area. For example, aviation fuel is still leaded, and the
national estimate of lead emissions from the consumption of leaded AvGas was
483 tons in 2011, according to the EPA's National Emissions Inventory [0].
Furthermore, the same NEI data shows airports as the top source of lead
emissions in 42 states (according to 2011 NEI data).

Leaded aviation fuel is used by planes which use internal combustion engines
instead of cleaner, more powerful, and more expensive jet engines. Most of
these small planes are for personal use.

I think the costs of lead abatement should be included in the price of AvGas,
or its use should be discontinued entirely.

[0] U.S. EPA. Calculating Piston-Engine Aircraft Airport Inventories for Lead
for the 2011 National Emissions Inventory. U.S. Environmental Protection
Agency, Washington, DC, EPA-420-B-13-040, 2013. Page 5

~~~
selectodude
>Leaded aviation fuel is used by planes which use internal combustion engines
instead of cleaner, more powerful, and more expensive jet engines.

Single engine personal aircraft are finally starting to switch over to Jet-A,
due to the extreme costs of 100LL avgas, the difficulty of procuring it
(there's only one TEL factory left in the entire world) and higher energy
density in kerosene. So we're on the right track.

~~~
TylerE
Huh? There are very very few GA engines capable of running on kerosene.

Conversions, especially of older, lower performance aircraft, to run on 87
mogas is MUCH more common.

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snovv_crash
This doesn't mean anything until there is more accountability for those
responsible. Look at Flint, and now Oakland too it seems.

~~~
stuckagain
Contamination in Oakland is primarily from its history of elevated freeways.
Responsibility for that contamination is diffused. How are you going to pin it
on any one party in particular?

~~~
anigbrowl
No need to pin it on one party. Rather than worrying about liability, better
to worry about who's bearing the cost of the externality, and what the future
costs of mitigating or not would be, with expenses to be paid from a general
fund. Going forward it's better to price externalities in at the early stages.

------
ern
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-
fli...](https://www.scientificamerican.com/article/the-brains-of-flint-s-
children-imperiled-by-lead-could-still-escape-damage/)

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
>"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.

~~~
AbrahamParangi
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
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-
tain...](https://www.scientificamerican.com/article/flint-s-lead-tainted-
water-may-not-cause-permanent-brain-damage/)

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
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.

~~~
ern
In a world of unlimited resources, you'd obviously keep moving the threshold
down, but according to OP, many jurisdictions were slow to react to the last
change, and many labs can't deal accurately with very low exposure levels
anyway (meaning more limited resources being expended to upgrade these labs).

Also, it seems like there are methodological improvements that can be made to
observational studies to get closer to an answer for a threshold without
literally poisoning people:
[https://www.ncbi.nlm.nih.gov/pubmed/27009351](https://www.ncbi.nlm.nih.gov/pubmed/27009351)

------
DoodleBuggy
Until the nation decides to pay the enormous costs associated with updating
ancient and dangerous infrastructure, does it even matter?

~~~
okreallywtf
This is a way to encourage that. How would you make the case for massive
public spending on infrastructure when lead limits are within those allowed by
the EPA? Not only that, but in an era of concerns over employment (whether
real or imagined), public spending can provide an economic boost as well [1].

[http://www.epi.org/publication/impact-of-infrastructure-
inve...](http://www.epi.org/publication/impact-of-infrastructure-investments/)

~~~
DoodleBuggy
Can you imagine congress passing a meaningful infrastructure bill?

~~~
noobermin
I really dislike Trump and voted for Clinton because of that, but one thing
that Trump did promise was to push infrastructure spending as it fit with his
populist message. Yes, his recent acts and cabinet picks don't inspire much
confidence that he will follow through with his more populist promises, but
there is at least that.

~~~
chris11
The major problem with Trump's infrastructure plan is the amount of suggested
privatization.

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MR4D
The dumb thought rolling around my head is, "Why? They can't even meet the
current limits!"

It worries me when regulators focus on moving the bar than meeting the bar.
Irrespective of whether the limit is right or not.

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dajohnson89
Honest question for anyone with knowledge about lead and health: I just moved
into an apartment that the city has cited for lead-based paint. How soon will
I die?

I asked the landlord, and he said don't worry about it (of course). He said
the risk is mainly for children, and that the lead is only kicked up when the
paint is scraped during remodeling or whatever.

~~~
mirimir
Well, the lead-containing paint is probably under several layers of lead-free
paint. Just don't mess with it. If there's any cracking or peeling, move.

~~~
mirimir
And get your blood lead checked _now_ , and then every few months. There might
be dust from prior renovation. Also, environmental testing kits are available.
They're not very sensitive, however, and there's the risk of false positives.

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e2kp
This is one of those reasons I decide to drink from water bottles.

Yes, there may be traces of antimony in it, but tap water, usually well
controlled at the reservoire, presents too high a risk of exposure to various
metals and bioforms due to decaying infrastructure.

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glbrew
Yeah, they should lower the threshold from Detroit to Cleveland.

