Discussed recently: https://news.ycombinator.com/item?id=30600539

A bit of clarification that was something that didn't occur to me immediately from the title:

The article is that half of the living US population was exposed to adverse lead levels as a child, not that half of US children today are exposed to adverse lead levels.

Makes sense. We had it lying around when I was a kid (in the 1960's).

We used to make impressions in clay with ordinary objects then fire up the shop gas torch, melt lead chunks in a forge pot, and pour it into our clay molds! It cooled in seconds, you could break the clay and have a lead toy. Fun!

I can’t find the reference but I’m pretty sure the majority of childhood lead exposure was via leaded fuel in cars.

In the 70s I made a pair of barbells melting 15 kg of the pipes that were replaced. Definitely fun!

> This amounted to a total loss of 824,097,690 IQ points, disproportionately endured by those born between 1951 and 1980

That is interesting, but what I really wonder about is more subtle cognitive effects. Did it make people meaner? More easily led? Less collaborative?

And as previously discussed here, lead was a known toxin when leaded gas was invented: https://www.smithsonianmag.com/smart-news/leaded-gas-poison-...

Discussion here: https://news.ycombinator.com/item?id=28500508

IQ has a interesting property in which it is multiplicative at the individual level, but not additive at the individual or collective level.

A 140+ IQ person is not 40% smarter than a 100 IQ person, but much smarter. Someone with an IQ of 100 may struggle at college math but someone with an IQ of 140 can do cutting edge research.

Likewise, adding two 120 IQ people does not equal a 140 IQ person. So even a dozen 100 IQ people working together will not be able to solve a math problem that a single person who has an IQ of 140 can solve.

There is the hypothesis of lead causing increased crime rates: https://en.m.wikipedia.org/wiki/Lead–crime_hypothesis

At the risk of stating the obvious, IQ points aren't a measure and adding them up doesn't yield a meaningful number. It's like adding up the numbers on football player's jerseys; if the total of a team's numbers goes up, that doesn't make the team better. Similarly, a reduction in the total amount of "IQ points lost" could easily correspond to more damage to cognitive intelligence caused by lead exposure.

If you're looking for a sports analogy, I think it's sort of like "change in total seconds it takes the players to run the 100-yard dash". Not directly tied to success, and in some sense a pretty arbitrary measure, but a number that's nonetheless concerning to see get worse.

I agree IQ is a pretty bad measure. And if you would like to go back and redo this study with a better one, I'm sure we (and this study's authors) would be grateful for the result. But since it's the measure we have, I'd say it's better than nothing, and this factoid is a good way to spark interest in the scale of the phenomenon.

I think they're talking about measures in the mathematical sense. It measures something real, but a difference of one IQ point doesn't mean the same thing across the entire scale, so you can't just sum IQ point differences.

Actually an amazing sports analogy. IQ is basically a metric same as any other startup metric. You can’t expect it to tell the whole story but it’s one useful thing that can be measured.

you are comparing something entirely cosmetic to something that is predictive and of real consequence

>> This amounted to a total loss of 824,097,690 IQ points, disproportionately endured by those born between 1951 and 1980

> At the risk of stating the obvious, IQ points aren't a measure and adding them up doesn't yield a meaningful number. It's like adding up the numbers on football player's jerseys; if the total of a team's numbers goes up, that doesn't make the team better. Similarly, a reduction in the total amount of "IQ points lost" could easily correspond to more damage to cognitive intelligence caused by lead exposure.

This is how I read it when I saw this number based on the title (I didn't read the article):

There are about 300 million people in total. Half of that is 150 million. A loss of 824,097,690 IQ points over 150 million people is over five point per person.

https://www.google.com/search?q=824%2C097%2C690+%2F+150+mill...

This is, of course, extremely misleading because someone born in the late eighties didn't suffer the same as someone born in the sixties. Similarly, someone born on or after January 1, 1996 didn't suffer as much as someone born in the eighties. Therefore, "five points per person" would be more misleading.

At the end, the actual number doesn't matter much. What matters is that the number conveys a sense of magnitude. We collectively lost almost a billion IQ points!

It doesn't matter what it exactly means. We just need to know that "they" robbed us. When I say us, it isn't just those of us in the US, I mean the whole world as the baby boomers voted and continue to vote (older people are more likely to vote compared to younger people). Who knows maybe if we had higher IQ, we wouldn't have fallen for nonsense like "starve the beast". If you stop to think for two seconds, reducing income because you think you are spending too much is asinine. It doesn't matter whether it is the federal government or a small family, it makes no sense to say well I am spending too much but if I had less income maybe my expenses would suddenly come under control.

Maybe with a slightly higher IQ, the people who voted in the eighties would have demanded this nonsense be nipped in the bud. I can't even imagine how much of a better place the world could be if we took a different path instead of following Ronald Reagan's shenanigans.

> What matters is that the number conveys a sense of magnitude. We collectively lost almost a billion IQ points!

But losing a billion IQ points might be less bad than losing 10M IQ points, because there is literally no scale.

> But losing a billion IQ points might be less bad than losing 10M IQ points, because there is literally no scale.

Maybe there is a bigger point I don't understand here (wouldn't that be ironic) but I only have about a hundred IQ points to play with and so does the average person (by definition?) so a billion IQ points is all the IQ points for ten million "average" people.

What am I missing?

You probably wouldn't detect it since there are so many effects at play here. For example, the parents of those born after WW2 in western countries are on average much younger than before (especially men) or after. Parental age has a significant effect on mutation rate and hence mental illness. As a consequence, bare intelligence is slightly increased in the same generation.

Also this article in Mother Jones: https://www.motherjones.com/environment/2016/02/lead-exposur...

> That is interesting, but what I really wonder about is more subtle cognitive effects. Did it make people meaner? More easily led? Less collaborative?

More boomer for sure

I recall as a kid, soldering circuit boards. I distinctly remember the label "low lead" and also the smell of the smoke it made. At times, and this is stupid, i would find myself chewing on a piece of the unburnt solder as i debugged a circuit board. Mistakes were made...

You were smelling the rosin in the solder burning.

All of that lead exposure likely pales in comparison to what was happening driving in a car with windows down (when AC wasn't common) and all the cars around you were burning leaded gas with zero emissions control equipment like catalytic converters. You were just getting blasted by air full of lead and other combustion products.

AC in general wouldn't help so much; air circulation would help a little

AC would help because the air coming into the car would pass through an air filter.

No, the AC filter is in now way able to remove fine particulate in most cars from decades ago.

When I was a kid, I explicitly didn't use non-leaded solder because I liked the smell of the leaded one. Mistakes indeed

The fumes from non-leaded solder are worse for you (make sure to have good ventilation). The lead doesn’t go into the air; the fumes are from flux. As long as you don’t eat the solder, and wash your hands after soldering, there’s no problem with hobby soldering using lead solder.

The reason to prefer lead-free solder is primarily because at industrial scale with tons of trashed electronics the lead becomes an environmental pollutant. For hobbyists, lead solder is easier to work with, and not a serious risk.

Pretty safe bet that kids playing with lead solder didn't wash their hands afterwards.

I mostly used lead-free solder as a kid (1990's and 2000's) but I still recall the acrid smell of flux fumes. I've accidentally had a few good whiffs that left me recoiling and coughing a bit. I wonder if that'll have any long term effects...

I too used leaded solder. But only because it was easier to use than the lead free versions

Btw, solder fumes are not lead, but flux.

Good to know. I've always wondered, cause I accidentally got a good whiff of it once and ... my cheeks were red for what felt like hours or a day. My memory of it is hazy.

I've got ventilation going much stronger now.

It’s not good to be inhaling flux either.

Generally speaking, if you can smell it, it’s not good for you to inhale.

Bad advice. There are a lot of odorless volatile compounds that will kill you. Human olfactory sense evolved to smell food, waste or rot; it didn't evolve to detect synthetic and contemporary chemicals invented in last 100 years.

Fallacy of the Inverse: https://en.wikipedia.org/wiki/Denying_the_antecedent

How so? Care to elaborate?

The only thing I am noticing that's left in my argument is that there are also bad chemicals that can be detected by human olfactory sense. My original point was that "Just because it has no smell, doesn't mean it is good for you", which is perfectly congruent and abdicates the fallacy you've listed.

>My original point was that "Just because it has no smell, doesn't mean it is good for you",

And their point was that that being true doesn't make the comment you replied to "bad advice" as you claimed.

My Dad was born in 1934 and growing up he had toy kits that consisted of lead, a smelter and casts of the toys/figures.

I can find these kinds of kits online from the 60’s but they all claim to be lead free. I wish I could find one of the original kits he had growing up.

I'm shocked by yours and similar comments. Did you simply assume that flux are solder are healthy?

(e.g. lead toxicity is well known since many centuries)

I'm guessing the health angle wasn't contemplated. Focusing on health wasn't that common before.

I’m glad I wasn’t the only one!

Does anyone know if lead levels matter much in adulthood? Found out my local water had lead, old municipal pipes. Drank it about ten years. Or possibly just two. Either way, wondering if I should be concerned or do anything beyond filtering the water (which I do now)

People have a lot of misconceptions about water infrastructure. Approximately 6-10M lead service lines still exist in today's world. (https://www.epa.gov/ground-water-and-drinking-water/lead-ser...) Most of that is kept away from you by treating water with a chemical that causes a rust layer to form over the lead, preventing it from getting into the water at dangerous levels. Phosphates are typically used for this purpose. (https://alliancewater.com/why-the-us-still-has-lead-service-...)

Cities do screw this up, as evidenced in Flint and other areas. Not all filters are designed to remove heavy metals or lead, so you need to be picking a filter based on that. (https://www.consumerreports.org/water-filters/make-sure-your...) There's also other stuff in the water, so picking the right filter for your area is important.

Whether you're an adult or a child lead poisoning is equally dangerous (https://www.mayoclinic.org/diseases-conditions/lead-poisonin...). It is something that can be tested for though.

To clarify: the measured levels from my tap were high, though not crazy high. High enough the city gave a filter to local residents and said not to drink the water from the tap.

7 micrograms per litre, legal limit 5. This was after running the water for a few min.

I wonder what happens after, say, an earthquake? Can pipes bend enough to cause cracks in the passivated layer and temporarily increase lead levels?

Yeah, they probably could, but the phosphates are always in the water so it'll reform and the amount of lead that gets into the water when disbursed is pretty low ppm (parts per million). The fundamental problem is that this infrastructure is costly to dig up and replace, and the key word here is "service lines". Those are the lines consumers are responsible for paying for. Cities that have lead lines should be working with the EPA to set milestones and goals for yearly replacements with federal funding though.

Generally speaking, it’s not something to freak out about. Usually lead is found in the service lines from the main to your house.

Unless the people who run your water utility are criminally negligent (ie. Flint, MI), you’re fine. Run the water for a few seconds before you drink it in the morning to flush out sediment, and if you’re worried, use a filter.

Your water utility is required to test and publish results - look at those as well to understand if there is anything to worry about.

Provided the municipality treats their water correctly the lead should not dissolve into the water. Did you actually have the lead levels tested in the water?

If you're concerned get a blood test for lead levels. No level is good for you but adult exposure is magnitudes less damaging than early childhood (while brain is still developing).

I recently petitioned my local councillor to have my service line replaced at cost to the city. My only expense was to hire a plumber to do the connection to the house (several hundred bucks); digging was covered by them.

Where?

Montreal. Lots of old pipes. They sent city workers to check, determined my unit’s levels were high and gave me a filter. Planning work in a few years.

lead exposure makes people dumb af and mentally ill

Crude, poor delivery but you may be on to something.

I am curious if this is why you see generational differences in mental models and belief systems (there is data showing an inverse relationship between religiosity and intelligence [1] [2]), and why younger, healthier cohorts operate with different mental models.

Riffing, if younger cohorts are healthier, you’d expect their average/aggregate cognitive ability to be higher, leading to social stratification.

[1] https://pubmed.ncbi.nlm.nih.gov/23921675/

[2] https://en.wikipedia.org/wiki/Religiosity_and_intelligence

I’m sure lead levels have some effect, but how do you control for “they grew up in a completely different world”?

I’d assume the latter is the primary cause of any major behavior differences, absent some pretty breathtaking science showing otherwise.

“Intelligence” is also a pretty goofy measure. If we’re talking about IQ, it’s basically “what quiz questions predict success measures, as defined by the social norms of whoever made the test”.

IMO that’s a pretty sketchy way to define intelligence. Certainly not the way I think about it colloquially. To me, success and intelligence are loosely correlated but very different traits.

Posted this in another thread about lead exposure: the Lead Exposure Elimination Project (https://leadelimination.org/) is an organization that's working to solve the problem of lead exposure internationally. I've been giving money on a monthly basis and have been blown away by their progress.

Whether it's increased crime or lowered IQ, lead is likely not as potent as the media hype would suggest.

According to a meta study of lead vs. crime the results are inconclusive. Very high exposure to lead my cause a couple point reduction of childhood IQ, which may be temporary and not everyone exposed to lead has a reduced IQ.

Regarding lead & IQ and lead & crime ,some links to studies (and the meta study):

https://greyenlightenment.com/2021/08/02/the-effects-of-lead...

Also, the median childhood exposure to lead in the US for far back as the 1970s was around 15 ug/dl, which was the peak, which may have only conferred .5-2 pt decline in IQ

https://ourworldindata.org/exports/lead-blood-usa-children_v...

Also, this contradicted by Flynn effect, which shows IQs to be rising.

This comment would be a lot more useful with a link to the specific study you're referring to, instead of a fairly vague hint of its existence.

Only tangentially related, but you may find the following little thread amusing: https://nitter.fdn.fr/literalbanana/status/15041549669984665...

Practically, what should one do to avoid lead poisoning here and now?

Lead petrol is banned. Lead paint is banned. Lead pipes are a problem in some areas, but let's assume we don't live in these areas.

What do we need to look out for?

My understanding is that the majority of lead exposure today comes from two sources: lead dust accumulation in older construction (lead paint is banned, but removal is usually not required), and lead contamination in consumer products.

The former is easier to avoid: make sure to maintain the integrity of the paint in your living space, particularly where it regularly encounters moisture or friction (like windowsills and mantles).

The latter is harder: lead is a useful industrial material, and it finds its way into all kinds of plastics, glass, etc. Dry spices can also have high amounts of lead, depending on the plant and the region it was grown in.

All of that said, lead is not like nuclear waste: it's not a latent risk. Leaded paint and lead jointing in pipes, when maintained correctly, do not pose an exposure risk. You can spend your entire life using lead tackles and lead solder without hurting yourself, as long as you take basic precautions during and after use.

Small plane fuel is still leaded. I know a few air fields in my area that were converted to housing developments and/or parks/retail/offices. I assume the ground is still contaminated in those areas, and any fruits from plants growing on it will be contaminated also.

I also assume small planes rain down lead wherever they fly.

Just wanted to add that it's planned to be phased out by 2030 now[0]. Kind of insane they're giving them that long if you ask me but I guess it's better than nothing.

[0]: https://www.faa.gov/newsroom/faa-industry-chart-path-elimina...

General aviation (contrast to "commercial aviation"), which is the only place leaded gasoline is really used even within the industry, died in the 1970s. Not sure of the exact bill but the FAA drastically tightened approval processes to the extent that essentially only commercial aviation has enough volume to make it financially viable to get through the regulatory approval process.

There's a few exceptions, like Cirrus and maybe Diamond, but almost all general aviation aircraft either predate those regulations entirely, or are in hardware configurations that predate those regulations and have been grandfathered. Sometimes - rarely - you get a new engine or whatever, but it's very rare that anyone goes for approval of a whole new airframe or anymore. It's the same reason Boeing prefers to add a dumb computer-assist system on the 737 MAX instead of just changing their airframe - change the airframe and you have to do a complete re-approval process.

In short, they are still using leaded gasoline because they're still using 1950s and 1960s engine designs (and in many cases, actual 60s/70s-production engines and airframes) because the FAA approval process makes it impossible/prohibitively uneconomical to replace them.

Not saying removing lead isn't important, but bear in mind this is essentially gutting public access to aerospace and aviation. We've already seen the loss of R/C aircraft as a hobby, the "feeders" into aerospace are getting pretty slim indeed.

I looked into this a short while ago and came to the conclusion that fruit is probably ok. It's root vegetables that are the worst and then leaf and stem, then fruit doesn't seem to pick much up even from fairly highly contaminated soil. I now can't find all the papers though, so YMMV.

Paint chips are the main thing. Don’t needlessly demolish anything and if you do, do it right, with containment and wet cleanup. And, ideally, a trained and licensed crew. Don’t let your neighbors DIY exterior painting, scraping, or demolition, or do it with a fly-by-night unlicensed contractor and no permits. Don’t let your kids chew on the window sills. Don’t garden for food without thinking about it first.

> Don’t let your neighbors DIY exterior painting, scraping, or demolition

WTF? Yes, go ahead and advocate responsible techniques. But if you're the type of meddling busybody that harasses others just for working on their own homes, don't be surprised when nobody listens to you.

The poster to whom you are replying is completely correct. It's not the same thing as thinking the windows they're putting in are ugly. It's not even like asbestos mitigation, where stupid decisions there only really impact the people who live there. These are health and safety risks to people around you, not just you yourself. It's a community concern.

Your neighbors' decisions around lead management and mitigation directly impact you and you are within your rights to insist that they follow proper safety procedures. To cast that as "meddling" or "harassment" is odious.

Sure, it's a community concern. This gives neighbors the right to express their concerns and offer advice and help, not to overbearingly insist that work is only done by "professionals" who magically bless the situation.

Legally, it's generally commercial activity (eg contractors) that is regulated. Thus, after you've talked to your neighbor about best practices for mitigating lead dust, you've effectively exhausted your options. After that point, not "letting" them DIY will basically consist of harassment.

I used to own a property management company and I have overseen multiple home remodels (while doing one largely by myself right now). Hazardous material management on a work site are not somehow beyond regulation because it's not "commercial activity", that's preposterous. Homeowner-executed projects can be stop-worked just like everything else and hazardous material management is a standard part of code enforcement.

As to your postscript--yes, clueless or careless DIYers probably need the hammer swung at them, and hard, when they do something to create negative externalities. You have the right to not be poisoned by your neighbors. Even if they make you sue them to enforce that right, that still isn't "harassment", and it is genuinely and deeply gross to characterize it as such.

These things obviously vary between jurisdictions, but from my own experience lead-painted material is not "hazardous" waste. In fact, last time I checked (~10yrs), the official guidance was to put it in municipal trash or a standard dumpster. Furthermore, I've had an inspector called on me while helping to paint a house, precipitated by a busybody neighbor. The inspector established that we were family, and then just left never to return - lead exposure is regulated as an occupational hazard, and none of us were being paid. And my experience is from a state known for overbearing regulations.

I got rid of the PS because it was needlessly obtuse. But trying to restate it nicer - coming at someone DIYing with the attitude that they should be hiring "professionals" instead, as opposed to offering constructive criticism and perhaps even help, is a guaranteed recipe for a failed interaction.

And unless you've got actual demonstrable harm from your neighbor's activities - more than a vague worry about the possibility of lead dust being carried by the wind - filing a baseless lawsuit is indeed best characterized as harassment. At a certain point, there is an threshold of blame that is impossible to adjudicate. Slightly elevated environmental lead is squarely in that territory (it could have also come from a piston plane flying overhead), which is why the real fix is to systematically eliminate the use of lead to begin with.

I'm sorry, can we go back to the part where i "don't let my neighbors" do something? Unless they are in violation of a law that is actually enforced by someone, I don't think I have standing to let or not let them do anything.

In American jurisdictions of which I am aware, there are such laws around handling hazardous materials (and lead, especially in particulate form, qualifies). In hypothetical places where there aren't, the concept of a tort still exists.

You do, in fact, "have standing" to not have your neighbors poison you. This is a good thing. It should be celebrated.

In which you have convincing demonstrated that libertarianism and lead poisoning are locked in a mutually-sustaining cycle of brain damage.

Negative externalities between neighbors is a thing. See noise pollution.

Yes, but by the time someone is trying to stop their neighbors from working on their own homes using the same mitigation techniques a licensed/insured contractor would, we're well past the point of discussing externalities and solidly into HOA-hellhole territory.

I think the point is that if they are _not_ using the same mitigation techniques, you have a right to prevent their DIY actions from poisoning you and your family. And if they don’t have a license or permit, how can you verify they are following best practice?

Led contamination risk is definitely more serious than HOA-hellhole

OP said nothing about evaluating their techniques, but rather a blanket "Don’t let your neighbors DIY exterior painting, scraping, or demolition".

> if they don’t have a license or permit, how can you verify they are following best practice?

What exactly do you think licenses/permits guarantee? At best, an inspector knows the least responsible crews and checks in on them more often. That's about it.

The only way you can actually verify someone is following best practices is to know what those practices are and observe their behavior. By expressing a belief that permitted professionals somehow automatically conform and DIYers automatically do not, one indicates that one has no idea what best practices actually are but yet feels qualified to judge anyway.

> What exactly do you think licenses/permits guarantee?

Licenses confirm that the person doing the work is trained in the best practices + safety for the work that they are doing. Permits ensure that they have filed a plan with the city/state that matches safety regulations, and that this plan is available for the public to review and comment on. It doesn't guarantee automatic conformity, but it shows that their plans have been confirmed _and_ provides an avenue to verify that they are conforming to those plans.

I can't confirm everything that a doctor does either, but I'd still much rather see a licensed one than an unlicensed one.

If you live in a development that was built in the days of lead paint, IMO it seems fair to notice if your next door neighbor is carelessly demo'ing or sanding the exterior. Lead dust from their work can blow into your life.

The CDC has a good site on lead exposure:

https://www.cdc.gov/nceh/lead/prevention/sources.htm

The biggest concerns are lead paint in older homes, contaminated soil, food and cosmetics, and toys and other consumer products.

another one: get your soil tested, don’t wear your shoes in your house

> don’t wear your shoes in your house

This is good advice for many other contaminants as well.

Is there anything that can even be done to treat lead exposure long ago?

> The half-life of lead varies from about a month in blood, 1-1.5 months in soft tissue, and about 25-30 years in bone (ATSDR 2007).

https://www.atsdr.cdc.gov/toxprofiles/tp13.pdf

Even low lead levels in children can cause developmental issues. Not necessarily abnormalities, but possible issues vary widely.

Chelating treatments, although I have no idea how they can be administered or used it if there are constraints to their use. I think it's unavailable at the pharmacy.

I remember because the molecule is quite funny it has some kind of slot to capture the lead atom.

Curious if theres any data on how US compares to other countries

This would be interesting to see - considering most European countries banned lead paint long before the US, I would expect exposure rates to be lower.

For leaded fuel, the European countries banned a few years after US so there was still some exposure.

https://en.wikipedia.org/wiki/Tetraethyllead#Phaseout_and_ba...

Well that explains a lot. Seriously though, for a wealthy first world nation the levels intellectual rational debate in America is generally pretty shockingly poor.

A lot of companies don’t hire people who were born before leaded gasoline was banned. For many roles with high mental load it’s seen as a liability.

Does lead exposure cause autism?

Explains so much

I'm from a family that has been in real estate since the 80s. Lead remediation was a mandatory requirement in the late 70s. There is almost no lead anywhere in the country except for cities where there were old industrial manufacturing plants or places where there was illegal dumping of materials.

You literally can't sell a home or purchase a home with lead issues because no one will purchase the property. There are exceptions where people are gaming the system by controlling the property and town inspection departments but largely lead paint poisoning is an old problem that was solved a long time ago.

The only reason children would have a drastic decreae in IQ is going to be a combination of Television and internet usage at extremely young ages which has deleterious affects on will-power, attentional focus, judgement, memory and visuo-spatial analysis. The lead argument really needs to go away it keeps popping up and it is literally impossible in most of the country.

I can tell you that lots of houses weren't remediated like you'd expect. An extra layer of paint, and now 50 years on since the 70s both are chipping sort of thing.

Yeah OP is completely wrong. There is tons of lead paint on the walls in just about every city in the US. Remediation has been completely ad hoc and the restrictions on selling a house with lead paint are almost always a single sheet o paper that says “Sign here to acknowledge that there may be lead paint.”

According to the EPA

>Many homes, including private, federally-assisted, federally- owned housing, and childcare facilities built before 1978 have lead-based paint

https://www.epa.gov/lead/protect-your-family-lead-your-home-...

Do you think they are lying?

It amazes me how long "the new thing has ruined the children" has been a trope.

You manage to combine two generations of it. Television started ruining children when the Boomers were growing up. The Millennials were ruined by the early internet. And now I hear the Zoomers are being ruined by TikTok. (Presumably Gen X was ruined by cable TV, which you left out.)

But that's just recently. The earliest iteration of this moral panic that I know of involved novels: https://www.economist.com/1843/2020/01/20/an-18th-century-mo...

That's right, the kids have been ruined since before America existed! Truly, it's amazing this steady worsening of the youth has not destroyed life as we know it.