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Comment by rayiner | Hacker News Reader

Look. In 1970, over 75% of kids in the US were never breastfed, which means they drank milk from BPA containing bottles from day 1. And they turned out fine. Don't get unreasonably worried about it. That white collar job with a lot of sitting that you're hoping he or she will get will do much worse things to the body. And if you're driving your kid around in the burbs, well BPA is in the noise compared to that staggering risk. Leading cause of death for kids 2-25. I have a two year old daughter who drinks out of clear plastic bottles and sleeps on a mattress containing fire retardant chemicals, and at the end of the day by far the biggest risk I expose her to is driving down to her grandparents' on the weekend.

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Following up on this, the opening paragraph to the Freakonomics chapter on parenting talks about how, as a new parent, your IQ drops 10 points and all sorts of marketers will completely overwhelm you with the fear that you are doing something wrong with your kids.

Take your kids to the doctor regularly and you'll be okay. If you are doing something that 80% of the rest of society is doing and it turns out to be a subtle mistake, there will still be lots of people around you who made the same mistake and will help you figure out how to recover.

Relax. Enjoy your kids! They'll turn into teenagers before you know it.

And they where also exposed to high amounts of environmental lead, and we know how that turned out: higher crime, lower academic achievement, more teen pregnancies, etc. Just because most of a society is exposed to something does not mean it's healthy.

Two interesting papers: Lead Exposure and Behavior: Effects on Antisocial and Risky Behavior Among Children and Adolescents [1], and How Lead Exposure Relates to Temporal Changes in IQ, Violent Crime, and Unwed Pregnancy [2], estimates serious deleterious effects ranging from lower iq, lower self control, increased violent crime, etc, stemming from childhood lead exposure via tailpipe emissions.

[1] http://www.nber.org/papers/w20366

[2] http://pic.plover.com/Nevin/Nevin2000.pdf

I have posted this before on HN, but I don't understand how, as lead levels continued to rise, IQs also increased during the 20th century. And someone pointed out in another comment, as blood lead levels have plunged, we should have seen the lost IQ points being recovered. Has there been evidence of a large gain in IQ since blood-lead-levels have dropped?

That presupposes that trace lead exposure (as opposed to larger doses) measurably harms IQ as opposed rather than manifesting in other kinds of neural/behavioral issues.

That is true-the lead-crime link seems compelling. But I've been browsing a fair amount on the subject, and the lead-IQ link is always quite heavily featured.

Some studies claim differences of 5 IQ points between children with blood lead levels between 5 and 10 micrograms per deciliter. Since blood lead levels are far lower than 5 for the majority of children nowadays, and much lower than they were when we were kids, these IQ differences should be clearly apparent between generations.

"Look. In 1970, over 75% of kids in the US were never breastfed, which means they drank milk from BPA containing bottles from day 1. And they turned out fine."

But did they really (turn out ok)?

How common were peanut allergies and obesity before 1970 for example?

I'm not saying that BPA cause peanut allergies or obesity. I am saying that kids are not turning out OK and it's fair to question whether something environmental is causing this.

http://www.pbs.org/wgbh/nova/body/jirtle-epigenetics.html

"Jirtle: We have recently demonstrated that exposure of pregnant mice to bisphenol A (BPA), a building block of polycarbonate plastics and epoxy resins used to make consumer items ranging from water bottles to dental sealants, significantly reduces DNA methylation in Avy mice (Dolinoy et al., Proc. Natl. Acad. Sci. USA 104: 13056-13061, 2007). This results in the birth of more yellow offspring, mice that become obese and have a higher incidence of diabetes and cancer as adults. Thus, there could be a connection between the increase in plastics in our environment and the rising incidence of obesity in humans. However, such an association will not be able to be demonstrated unequivocally until the expression and function of genes involved in human obesity are shown to be altered by BPA."

People are more overweight these days because they eat 250 note calories per day than people in 1970: http://wholehealthsource.blogspot.com/2008/12/us-weight-life.... Increased caloric intake explains almost all of the rise in obesity: http://www.sciencedaily.com/releases/2009/05/090508045321.ht.... Why do we eat more than in 1970? For the same reason we buy cars more often, phones more often, have several TV's in each household: we're a consumer culture and we have more resources to consume.

If you want to look for the root cause, look at food businesses and advertising. The Starbucks' of the world that make more profits than the coffee shops of yore by selling higher calorie foods for even higher prices. A coffee and donut at DD has half the calories of a latte and scone at Starbucks.

The "eating more" and "environmental influence" explanations are not mutually exclusive. One could be causing the other--chemicals that mimic hormones could be influencing appetite or satiation, for example.

Yeah we see that careless phrase all the time - "We turned out fine". Except when we didn't. Its observer bias I think.

My Dad used to say "In my day we didn't throw out food when it had mold; we'd just skim it and cook it again!" My sister came back with "Yeah Dad, and in your day people died for no reason."

They almost certainly didn't die from the mold.

That's just semantics. You don't die from smoking either. It increases the risk of several types of cancer. Just like most forms of mold.

Molds that grow on bread or food in the refrigerator are vanishingly unlikely to produce aflatoxin, the carcinogen you're referring to here. The real risk of food-borne illness from moldy kitchen foods are allergic or bacterial.

There are dozens of toxins harmful to humans that can be identified in different types of mold, of which there are many. Some have been known to raise the risk of tumors. One specific example is ocratoxin.

I did not mention aflatoxin because it is bad for you on a whole other level. Fortunately it's not very common.

> And they turned out fine.

Everyone says this.

"I smoked 40 cigarettes a day, and it hasn't harmed me!"

"My mother dropped me on my head every day, and it hasn't harmed me!"

Removing an unnecessary risk in child development is what this is about. If it makes sense to remove the risk, then you should.

I've never known anyone to say either of those two things.

So you're saying I have to buy an even better car seat. Maybe a new car. Got it!

(My boy is 8 days old)

Polycarbonate bottles were not in widespread consumer use back in 1970.

Even though this particular polymer was originally discovered over 100years ago, and relatively modern production techniques were patented in the '50's, widespread use to replace glass in "water cooler" type bottles did not begin until the '80's.

Later this polymer moved down the chain into smaller bottles.

The invention of polycarbonate at GE in the '50's is interesting:

"[Fox's] discovery, made within eight months of his joining GE, was a serendipitous byproduct of the wire enamel project. The byproduct would prove far more important than the original objective."

from "Unlikely Victory: How General Electric Succeeded in the Chemical Industry"

http://books.google.com/books?id=bgdvYy80AHUC&pg=PA71#v=onep...

...and in the 70's homes were painted with lead paint and the cars burned leaded gas, the outside air was full of asbestos brake pad dust, cribs could strangle you 10 different ways, and everyone around you smoked, including your mother. We all survived.

He's right. There are worse things to worry about.

Well .... I don't know about everyone ....

survivor bias

Hmm, many good things in society peaked in 70s... <dons tinfoil hat>

> And they turned out fine.

Except for that they didn't turn out fine. 1 in 5 couples in the US is now infertile, which is why this thread is here in the first place.

Given that almost 40% of married couples in the U.S. are 55+, I'd imagine more than 1 in 5 couples is infertile...

1 in 5? That seems, well, like nonsense.

Given they're estimating up to 1/3 of women could have PCOS, which is caused by testosterone... the hormone BPA is supposed to interfere with, 1/5 is actually comparatively low. I know about 10% of women have fertility complications due to PCOS, so attributing an alleged 1/5 to BPA is laughable.

Infertility is evolutionarily advantageous in a species that requires a lot of parental investment. The fertility rate of women in the 16-25 is insanely high, given there used to be a near 20% mortality per pregnancy.

The majority of the infertility is due to advanced age, and nothing else. A woman in her late 30s has almost the same chance of getting pregnant in a year that a teenager does in a month.

Source? There's a lot of potential confounding variables there...

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