CDC considers lowering threshold level for lead exposure | Hacker News Reader

CDC considers lowering threshold level for lead exposure

reuters.com

98 pointsfinid52 comments

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

>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.

That and the higher efficiency of diesels (assuming you're talking about little planes). Still it's a really long road ahead. For GA aircraft I think a better solution right now is a drop in replacement for 100LL (which is getting worked on) or getting leased engines certified for mogas or modified to run on it.

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.

The AOPA is the NRA, essentially. They don't care about the public health problems they cause. They just want to fly around in their little WW2-technology toys.

This makes me think of A Snow Mobile for George [1]. I'm not sure what the lead pollution impact of 2 stroke engines are (probably awful if you were able to find/use leaded gas) but in terms of low-hanging fruit its a perfect example of how regulation or deregulation can have a large effect on pollution.

Growing up using 2 stroke weedeaters and chainsaws I had no idea how polluting they are. Granted we were using terribly small amounts of gas compared to snowmobiles but it still made me think of the health dangers of the exhaust. I have some nostalgic feelings towards the smell of 2 stroke exhaust (diesel exhaust as well) but after seeing the documentary I wouldn't buy another 2 stroke anything.

http://www.imdb.com/title/tt1314278/

"Growing up using 2 stroke weedeaters and chainsaws I had no idea how polluting they are."

Terribly polluting. However, my understanding is that there is no potential for "fixing" chainsaws since a 4 stroke engine cannot run upside down - which is a requirement for a chainsaw.

Am I mistaken ?

Luckily we're starting to see a lot of battery operated chainsaws come onto the market with higher density Li-ion batteries. We're demoing a dewalt[1] chainsaw at my fire department and I have been using a Bosch reciprocating saw with a brush blade for light tree work for two years now ... but this is all light duty stuff and cannot replace large chainsaws...

[1] http://www.dewalt.com/products/power-tools/outdoor-power-equ...

2-stroke engines are lubricated by their own fuel mix. There's no reason you can't mix oil and gas in a 4-cycle fuel mix. This is what the Stihl 4-cycle chainsaw does.

Honda also makes small 4-stroke engines that work in any position, because Japan is awesome.

> This makes me think of A Snow Mobile for George

For some reason my immediate impression from the title was: "Like Flowers For Algernon, but with lead poisoning."

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

Just because there's accountability doesn't mean that suddenly people become more competent.

Yes it does if punishments are superior the benefits and are well known.

That can affect malice or apathy, but not incompetence.

What does "those responsible" even mean?

There are a lot of people that directly share some of the responsibility for failing to properly treat the Flint River water after the switch (and for switching in the first place).

But for instance, are the people that voted to start bankrupting the city in 1985 also responsible for the crisis?

How about the people that failed to replace their lead water supply lines after it became clear how dangerous lead can be?

And on and on.

Are you advocating that no one be held responsible? Of course things can be complicated, but in light of the evidence, it isn't as hard to disentangle as you suggest.

Not at all. In a case like Flint there will be people with clear culpability for the poor decisions that were made.

But there are millions of lead service lines elsewhere in the US (the pipes from the street to the house).

Who's "responsible" for them?

Wouldn't the answer to this question depend on which pipes you're talking about? Are you arguing that Flint is the only place where lead had a cause?

Kind of amazing that somebody twice asks "who's responsible?" and instead of an answer to a straightforward question, they're accused of claiming nobody is responsible. Why not just answer the question?

> a straightforward question

It's not a question with an objective, simple and thus straightforward answer.

All the more reason not to attack the person asking it.

Do you mean accountable in the sense of the aviation industry (which hasn't had a major US airline crash in over 15 years) or the default political process?

There are literally thousands of cities with various levels of unsafe water. I had some extended familiy members whom all stupidly lived in the same house, drank/bathed/etc using the tap water near Durango, Colorado... and they all died prematurely of various terrible diseases like numerous forms of cancer.

Water isn't the only issue either. Our city has higher levels of lead than Flint does, but it's consumed through means other than water. http://www.pahomepage.com/news/18-pa-cities-lead-higher-lead...

Given the premise how can you you possibly come to the conclusion that the cause was the water.

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?

Do you have a source? There has been no leaded fuel (for on-road use) in over 20 years.

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.

What kind of accountability are you looking for in Oakland? You're looking at a history involving a battery factory, lead paint, and freeways that stretches back 60+ years. Who is there that can be held to account today?

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...

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.

>"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.

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.

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.

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...

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).

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.

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

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

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

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...

Can you imagine congress passing a meaningful infrastructure bill?

If there's money in it for someone, yeah.

There may be something good about a corrupt administration full of real estate and construction-connected people. They might borrow like crazy to build stuff, rather than borrowing like crazy to make explosive gunbomb supertank multi-vehicle warheads and feed hundreds of thousands of military subcontractors.

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.

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

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.

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.

You probably won't unless you are eating the paint off the wall or the paint is disintegrating and turning into dust.

Quite often the most effective way to deal with lead paint is to leave it alone.

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.

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.

You won't die, but your children will be stupid and violent.

You should get some of these LeadCheck swabs and test the dust and painted surfaces in your environment: https://www.amazon.com/3M-717834209102DUPE-LeadCheck-Swabs-8... .

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.

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

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