How Chemicals Affect Us
By NICHOLAS D. KRISTOF
Published: May 2, 2012
Scientists are observing with increasing alarm that some very common hormone-mimicking chemicals can have grotesque effects.
Damon Winter/The New York Times
Nicholas D. Kristof
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A widely used herbicide acts as a female hormone and feminizes male animals in the wild. Thus male frogs can have female organs, and some male fish actually produce eggs. In a Florida lake contaminated by these chemicals, male alligators have tiny penises.
These days there is also growing evidence linking this class of chemicals to problems in humans. These include breast cancer, infertility, low sperm counts, genital deformities, early menstruation and even diabetes and obesity.
Philip Landrigan, a professor of pediatrics at Mount Sinai School of Medicine, says that a congenital defect called hypospadias — a misplacement of the urethra — is now twice as common among newborn boys as it used to be. He suspects endocrine disruptors, so called because they can wreak havoc with the endocrine system that governs hormones.
Endocrine disruptors are everywhere. They're in thermal receipts that come out of gas pumps and A.T.M.'s. They're in canned foods, cosmetics, plastics and food packaging. Test your blood or urine, and you'll surely find them there, as well as in human breast milk and in cord blood of newborn babies.
In this campaign year, we are bound to hear endless complaints about excessive government regulation. But here's an area where scientists are increasingly critical of our government for its failure to tackle Big Chem and regulate endocrine disruptors adequately.
Last month, the Endocrine Society, the leading association of hormone experts, scolded the Food and Drug Administration for its failure to ban bisphenol-A, a common endocrine disruptor known as BPA, from food packaging. Last year, eight medical organizations representing genetics, gynecology, urology and other fields made a joint call in Science magazine for tighter regulation of endocrine disruptors.
Shouldn't our government be as vigilant about threats in our grocery stores as in the mountains of Afghanistan?
Researchers warn that endocrine disruptors can trigger hormonal changes in the body that may not show up for decades. One called DES, a synthetic form of estrogen, was once routinely given to pregnant women to prevent miscarriage or morning sickness, and it did little harm to the women themselves. But it turned out to cause vaginal cancer and breast cancer decades later in their daughters, so it is now banned.
Scientists have long known the tiniest variations in hormone levels influence fetal development. For example, a female twin is very slightly masculinized if the other twin is a male, because she is exposed to some of his hormones. Studies have found that these female twins, on average, end up slightly more aggressive and sensation-seeking as adults but have lower rates of eating disorders.
Now experts worry that endocrine disruptors have similar effects, acting as hormones and swamping the delicate balance for fetuses in particular. The latest initiative by scholars is a landmark 78-page analysis to be published next month in Endocrine Reviews, the leading publication in the field.
"Fundamental changes in chemical testing and safety determination are needed to protect human health," the analysis declares. Linda S. Birnbaum, the nation's chief environmental scientist and toxicologist, endorsed the findings.
The article was written by a 12-member panel that spent three years reviewing the evidence. It concluded that the nation's safety system for endocrine disruptors is broken.
"For several well-studied endocrine disruptors, I think it is fair to say that we have enough data to conclude that these chemicals are not safe for human populations," said Laura Vandenberg, a Tufts University developmental biologist who was the lead writer for the panel.
Worrying new research on the long-term effects of these chemicals is constantly being published. One study found that pregnant women who have higher levels of a common endocrine disruptor, PFOA, are three times as likely to have daughters who grow up to be overweight. Yet PFOA is unavoidable. It is in everything from microwave popcorn bags to carpet-cleaning solutions.
Big Chem says all this is sensationalist science. So far, it has blocked strict regulation in the United States, even as Europe and Canada have adopted tighter controls on endocrine disruptors.
Yes, there are uncertainties. But the scientists who know endocrine disruptors best overwhelmingly are already taking steps to protect their families. John Peterson Myers, chief scientist at Environmental Health Sciences and a co-author of the new analysis, said that his family had stopped buying canned food.
"We don't microwave in plastic," he added. "We don't use pesticides in our house. I refuse receipts whenever I can. My default request at the A.T.M., known to my bank, is 'no receipt.' I never ask for a receipt from a gas station."
I'm taking my cue from the experts, and I wish the Obama administration would as well.
read the jungle if you want to understand why we need food regulation. it's not a recent problem. consumers deserve transparency and yes people are free to make their own decisions.
jordan"besides the unknowns being discussed, there are certainly unknown
unknowns still lurking out there."
ah the unknowns unknown of the unknown unknown.
they are such a scar unknownIf you want to talk about unknowns and assume that things which worry you are unknown by everyone rather than just you like the toxic doses and effects of things like arsenic then make sure to apply the same logic to
Rotenone(an "organic" pesticide which is extremely toxic to fish and other aquatic life and which has to be used in far larger quantities than non-organic pesticides)
Pyrethrin (probably safe but some Pyrethroids are suspected to have effects on brain development)Sabadilla (repeated small doses showed possible cumulative effects)All of which can be used in "organic" farming. Ever tasted neem oil?because where the harsh synthetic compounds have to go through a battery of tests and regulation the organic stuff is rarely subjected to the same scrutiny so we are left with lots of unknowns in "organic".
On Thu, Apr 26, 2012 at 11:54 PM, Jordan Miller <jrdnmlr@gmail.com> wrote:
I truly wish that biology were as simple as the formulae and logic
being laid out in these discussions. unfortunately it's not.
besides the unknowns being discussed, there are certainly unknown
unknowns still lurking out there. I already mentioned thalidomide as
an example of what can happen when we as a society rush into things
with a "what could possibly go wrong" mentality.
we need to balance our goals for efficiency with the humility to
realize we don't know everything and that best intentions often lead
to unintended consequences.
when I have a choice, I err on the side of organic. that is a
regulated term in the US so you legally know what you are buying.
that's why it's so popular. plus it tastes better (ever had celery
where you could taste the pesticides? I have.).
cheers,
jordan
On Apr 25, 2012, at 12:10 AM, Nathan McCorkle <nmz787@gmail.com> wrote:
> On Tue, Apr 24, 2012 at 9:06 PM, Jordan Miller <jrdnmlr@gmail.com> wrote:
>> I guess we can agree to disagree.
>>
>> cheers,
>> jordan
>
> Realistically/scientifically though, that isn't a valid answer, if proof exists.
>
>> On Apr 24, 2012, at 8:05 PM, Simon Quellen Field <sfield@scitoys.com> wrote:
>>
>> By 'chemicals', what exactly do you mean?
>> I don't necessarily want fewer proteins, sugars, fats, vitamins, minerals,
>> etc., and those are all chemicals.
>> In fact, the entire mass of the chicken is chemicals, so eliminating all of
>> them leaves me nothing.
>>
>> Do you want all traces of selenium removed from the chicken?
>> The LD50 is between 12 and 38 mg/kg.
>> The LD50 for arsenic is much higher at 185 to 6400 mg/lg.
>> So selenium is many times more toxic.
>> And yet it is essential to your living past the next few weeks.
>>
>> Small amounts of arsenic are recommended for the health of the chicken.
>> But because people think it is a poison, they are afraid of it in their
>> food.
>> But there is belladonna in your organic tomatoes and potatoes, and yet that
>> is OK with you. It also is more deadly than arsenic.
>
>
> Simon has a point, but only gives the LD50 for the compounds, rather
> than the recommended daily allowance (RDA, the easiest metric I could
> find for this sort of thing, it may not be up to date though)
> http://ods.od.nih.gov/factsheets/selenium-HealthProfessional/
>
> Arsenic
> http://www.ead.anl.gov/pub/doc/arsenic.pdf
> "The acute lethal dose to humans can be about 2 to 20 mg/kg body
> weight per day (mg/kg-day)"
> "Ingesting small amounts over time produces chronic effects such as
> skin darkening and formation of corns, damage to peripheral nerves,
> cardiovascular system effects, hair and appetite loss, and mental
> disorders. "
> "Arsenic can also cause reproductive/developmental effects, including
> spontaneous
> abortions and reduced birth weights. Epidemiological studies indicate an
> association between arsenic concentrations in drinking water and increased
> incidences of skin, liver, kidney, lung, and bladder cancers"
> " Limited information is available on the joint toxicity of
> arsenic with other chemicals. For neurological effects, the predicted
> direction of
> joint toxicity of arsenic and lead is greater than additive, whereas
> the joint toxicity
> of these metals is predicted to be less than additive for the kidney and
> hematopoietic (blood-forming) system."
>
> And they've established toxicity dose-response effect guidelines
> Cancer Risk
> Inhalation UR
> 4.3 per
> mg/m3
>
> Oral SF
> 1.5 per
> mg/kg-day
>
> Non-Cancer Effect
> Oral RfD
> 0.0003
> mg/kg-day
>
>
> Sooo, what the NYT article lacks is the concentrations found.
>
>
> --
> Nathan McCorkle
> Rochester Institute of Technology
> College of Science, Biotechnology/Bioinformatics
>
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