Lead exposure is a global health problem that we have a clear path to solving - enable governments to track and remove sources of lead. If you're looking for a worthy recipient of your EOY donations, do check out the Lead Exposure Elimination Project:
There are better causes to donate to, in my opinion. Pb is nasty stuff, but the purported risks have been inflated beyond what's actually grounded in solid evidence.
The term "Pb poisoning" has two different meanings: traditionally it's referred to blood lead levels above about 50 mcg/dL, at which demonstrable symptoms occur (slowed reaction times, etc). But in recent decades, it's also used to describe much lower levels (>15 mcg/dL, >10 mcg/dL, or even >5 mcg/dL), for which the only evidence of harm comes from observational studies.
Observational studies establish correlation, not causation, and there are good reasons to doubt that the observed correlations are due to Pb neurotoxicity. The relationship between Pb exposure and cognitive/behavioral outcomes is intractably complicated, because for most children Pb exposure is primarily from dirt/dust ingestion, which in turn correlates with a child's developmental status, household cleanliness, and subtle aspects of parenting behaviors (in addition of course to more widely appreciated factors like age/condition of the home). Poor nutrition also causes higher BLLs.
It's been demonstrated that publication bias in the Pb literature has steadily risen over time, as reported effect sizes have increased. Several studies have found Pb correlations which resemble a U curve, where children with the highest blood lead levels have better cognitive/behavioral outcomes than those with intermediate BLLs (because outside the range of BLLs which are primarily driven by dirt/dust ingestion, "something else is going on", which doesn't correlate as well with cognitive/behavioral outcomes).
Dirt/dust ingestion (and therefore, BLLs) drop precipitously around age 2, because this is around the time when children outgrow mouthing behavior - some children a bit earlier, some children a bit later. BLL measurements at this age therefore a metric of developmental status. Or alternatively, this is the age at which "lead causes the most harm".
My argument is of course not that you should go paint your child's nursery with chrome yellow. Ingesting paint chips can be enough to put a child into the "actual lead poisoning" BLL range (drinking water from lead pipes generally cannot). But excluding exposure from leaded gasoline (which was formerly the dominant source of exposure, but which has fortunately been banned almost everywhere) and people living near smelting facilities, it's probably not the scary ubiquitous IQ-point larcenist that it's made out to be.
This remarkably old advice from a time before modern water treatment, sacrificial anodes, and automated temperature control is also why so many recipes instruct to "fill a pot with cold water" before it's boiled.
Although, seeing the inside of an old water heater is all anyone would need to convince them to leave the hot water for washing.
>Although, seeing the inside of an old water heater is all anyone would need to convince them to leave the hot water for washing.
You're talking about all the mineral sediment gunk that accumulates in them? But that's stuff that was in the cold water supply to the water heater but not in the hot water it emitted. It's evidence of its cleaning action.
There are places where the hot water is in an open (!) container in the attic and it could have dead rodents, etc. in it. Ireland, for one - which is part of the persistence of separate hot/cold taps in bathrooms.
Anecdotally, many homeowners are unaware of the existence of the sacrificial anode, and suffer premature water heater failure as a result.
Also anecdotally, some water heater replacement specialist contractors take every precaution to keep customers ignorant on this: No post-mortem examination, no mention of the issue, withholding of the printed manual accompanying the new replacement.
We have a hot water dispenser in one of our kitchen sink popouts; it's tremendously convenient. It's an on-demand heater that makes 82C instantly for tea.
If it’s a lead trap… wouldn’t that mean the water that comes out has less lead in it than the water that goes in? Assuming the water going into the heater is the same as the water coming out of your cold tap.
No, the article states that lead particles from upstream get trapped inside the water heater, which then gradually dissolve, especially when left stagnant overnight.
“The flushing helped significantly in almost every case. Among water heaters where water levels first tested above 50 ppb, flushing dropped the lead levels on average from 456 ppb to 20 ppb”
They took samples from the tank as I understand before and after flushing. If it’s in the sample some of it presumably goes to the water you use.
This is a really stupid testing method. They should have tested both water supplies at the faucet. This does seem to indicate the hot water tank is removing lead from the water and thus you would be better drinking it than cold unless something is going on between the heater and your faucet.
Water that's been sitting in a heater tank is oxygen-deprived and tastes dull when you use it for food preparation. That's the main reason to use aerated cold water instead of water from the hot-water system.
In some houses, the hot water is fed by an open header tank in the ceiling. Whatever dust, dead mice or bird poos fall into that, can contaminate the tap water. I went off drinking hot water as a kid after seeing the deep layer of fine dust built up in the bottom of it.
Unless you have a tankless water heater and no lead pipes in your house, in which case it’s fine to use the hot water from the tankless water heater for food / coffee / tea. At least that’s my understanding.
That's my understanding also. I only do it if I was already using hot water recently though. It seems pretty wasteful to pour all of that perfectly good cold water down the drain while I wait for the hot stuff to get to the faucet.
Most dishwashers are connected to hot water. Some higher end dishwashers can work with cold water, but the cheaper ones don’t. Does this mean using a dishwasher is a problem as well?
Probably not. Most of the water runs off the dishes. A very thin film remains that evaporates in the dry cycle, and even at that a lot of it will bead up and run off completely.
I don't follow. My hot water is heated up about 60cm before the tap, as it runs through. Is that a regional thing? Are you saying that you're keeping a large quantity of water at temperature at all times just in case someone might need it later? Wouldn't that be super inefficient energy-wise?
This is the standard North American approach, we have large insulated tanks that hold water at generally 38-48 degrees Celsius. My home uses a 40 gallon "water heater" using natural gas with an always burning pilot light. It's possible to "run out of hot water" as a result.
The common statistics I've heard is 30% of household energy usage goes to keeping the hot water heater at temp. How much of your power usage is water heating?
All environmental sources of lead that can readily contaminate humans should be removed. This is a good move. It would be great to see an international treaty on this, with goals and enforcement for signatories.
> We estimate that piston-engine aircraft have consumed approximately 38.6 billion gallons of leaded avgas in the U.S. since 1930, excluding military aircraft use of this fuel, emitting approximately 113,000 tons of lead to the air.
It is changing fast. Now that the lead free avgas is available for a trivial paperwork STC for all engine types, almost all the pilots I know are pestering their fields to switch. For GA aircraft.. things are in a wild shift first now.
An unleaded fuel for small planes was approved last year by the FAA, but it seems it's not available from distributors yet. I found a story about plans for Half Moon Bay to switch to it next year, maybe:
I mean, I’ve got to imagine the days of piston-engine aircraft are limited for other reasons in any case; if charged sensibly for CO2 emissions they wouldn’t be particularly economic for most use cases.
My favorite part in the bay area is how those small planes fly from Palo Alto airport, right through East Palo Alto to make sure poor kids stay underprivileged so that a bunch of rich folks can keep their hobby.
Its been on the books since the 90's, but it would cost too much just to repaint lead painted homes, so nothing much has gotten done. Highlights of the program: https://www.cdc.gov/nceh/lead/about/2000s.html
This seems like a lame excuse. Surely the USA can up their water plumbing requirements without replacing lead-based paint on other surfaces. Other nations have regulated this for decades now. It's about progress, not perfection.
At the cost of hundreds of billions and disruption of nearly every road in the USA, yes.
Doing it in the more vulnerable areas should be done first and if the lead solder has stabilized, work those areas last. Over a period of 20-30 years is better since that's roughly how long it took to install in the first place. This would lower the price and economic costs too. (this is what they do btw)
How harmful is lead in solder used to join copper pipes? Lead free solder was mandated only around 1986, so presumably there are a lot of copper pipes around using solder containing lead.
The exposed/wetted area of a soldered joint is pretty damn small and I’d expect those 40 year old joints have reached an acceptable steady state by now.
That’s not an excuse to use leaded solder on supply pipes as plumbing with lead-free solder is perfectly easy, but I don’t sweat* the old copper pipes in my 1920s home.
I'd imagine the extremely tiny portion of solder exposed to the water supply is nothing compared to the "lead-free" brass fittings which were permitted to contain various non-zero amounts of lead depending on the year, and still do.
you have two problems with new formulations though. one is lead-free solder seldom works as well as the box claims. two, antimony is somewhat concerning from a toxicity standpoint though i'd say less than lead
i wonder if we don't just quit and go to brazing all joints. rod is pricier than solder and takes more heat but probably less toxic and certainly more dutable
non-zero harm but it's necessarily a lot less than making the whole thing out of lead. think about the difference between a square inch of lead exposed per joint versus many square feet. not a one-to-one comparison since the shear stress at a joint will be higher, but such a relatively smaller area it will have a relatively tiny impact.
Readit News
https://leadelimination.org/
The term "Pb poisoning" has two different meanings: traditionally it's referred to blood lead levels above about 50 mcg/dL, at which demonstrable symptoms occur (slowed reaction times, etc). But in recent decades, it's also used to describe much lower levels (>15 mcg/dL, >10 mcg/dL, or even >5 mcg/dL), for which the only evidence of harm comes from observational studies.
Observational studies establish correlation, not causation, and there are good reasons to doubt that the observed correlations are due to Pb neurotoxicity. The relationship between Pb exposure and cognitive/behavioral outcomes is intractably complicated, because for most children Pb exposure is primarily from dirt/dust ingestion, which in turn correlates with a child's developmental status, household cleanliness, and subtle aspects of parenting behaviors (in addition of course to more widely appreciated factors like age/condition of the home). Poor nutrition also causes higher BLLs.
It's been demonstrated that publication bias in the Pb literature has steadily risen over time, as reported effect sizes have increased. Several studies have found Pb correlations which resemble a U curve, where children with the highest blood lead levels have better cognitive/behavioral outcomes than those with intermediate BLLs (because outside the range of BLLs which are primarily driven by dirt/dust ingestion, "something else is going on", which doesn't correlate as well with cognitive/behavioral outcomes).
Dirt/dust ingestion (and therefore, BLLs) drop precipitously around age 2, because this is around the time when children outgrow mouthing behavior - some children a bit earlier, some children a bit later. BLL measurements at this age therefore a metric of developmental status. Or alternatively, this is the age at which "lead causes the most harm".
My argument is of course not that you should go paint your child's nursery with chrome yellow. Ingesting paint chips can be enough to put a child into the "actual lead poisoning" BLL range (drinking water from lead pipes generally cannot). But excluding exposure from leaded gasoline (which was formerly the dominant source of exposure, but which has fortunately been banned almost everywhere) and people living near smelting facilities, it's probably not the scary ubiquitous IQ-point larcenist that it's made out to be.
https://blogs.edf.org/health/2018/02/26/lead-hot-water-issue...
They’re lead traps.
Although, seeing the inside of an old water heater is all anyone would need to convince them to leave the hot water for washing.
You're talking about all the mineral sediment gunk that accumulates in them? But that's stuff that was in the cold water supply to the water heater but not in the hot water it emitted. It's evidence of its cleaning action.
Also anecdotally, some water heater replacement specialist contractors take every precaution to keep customers ignorant on this: No post-mortem examination, no mention of the issue, withholding of the printed manual accompanying the new replacement.
They took samples from the tank as I understand before and after flushing. If it’s in the sample some of it presumably goes to the water you use.
I assume this is related to the availability of 230v/15A for the heater element.
If you drink the dish water OTOH...
Deleted Comment
Every single small plane still uses leaded gas.
Flying overhead, all days, every day. At low altitudes.
And no one is changing that any time soon. As in tens of decades. Just leaded gas everywhere in the sky.
> We estimate that piston-engine aircraft have consumed approximately 38.6 billion gallons of leaded avgas in the U.S. since 1930, excluding military aircraft use of this fuel, emitting approximately 113,000 tons of lead to the air.
https://www.hmbreview.com/news/airport-plans-transition-to-u...
Deleted Comment
Doing it in the more vulnerable areas should be done first and if the lead solder has stabilized, work those areas last. Over a period of 20-30 years is better since that's roughly how long it took to install in the first place. This would lower the price and economic costs too. (this is what they do btw)
That’s not an excuse to use leaded solder on supply pipes as plumbing with lead-free solder is perfectly easy, but I don’t sweat* the old copper pipes in my 1920s home.
https://www.copper.org/applications/plumbing/techcorner/sold...
* That pun was inadvertent.
But with most things, the dose makes the poison.
i wonder if we don't just quit and go to brazing all joints. rod is pricier than solder and takes more heat but probably less toxic and certainly more dutable
https://www.youtube.com/watch?v=ZY0IscIvue4