"Avoiding Adult Exposure to Pthalates"
Most of the attention on phthalates,
a group of hormone-disrupting chemicals found in PVC plastics,
has been on fetal and child health,
particularly regarding genital and behavioral development
such as incomplete virilization in infant boys
and reduced masculine play as they grow up,
and for girls an earlier onset of puberty.
But what about affecting hormonal function in adults?
Men exposed to high levels of phthalate
have lower testosterone levels,
but that was for workers in a plastics plant.
In the general population, the evidence is mixed.
A study in Sweden of men in their 20’s
found no effect on testosterone,
whereas a U.S. study on men in their 30’s did,
at levels of exposure much lower than those factory workers.
When there’s conflicting evidence like this,
ideally we’d put it to the test,
but you can’t ethically expose people,
so scientists have come up with convoluted methods
like implanting the testicles from human fetuses into mice
to keep them growing,
but we want to know about the effects on adult testicles,
which are harder to procure…
until now.
Consent was obtained from all the donors.
Now I’ve heard of blood donors,
but this is a whole another level.
No, they obtained the testicles from prostate cancer patients
who underwent castration to control their disease.
And indeed they were able to get direct evidence
that phthalates can inhibit testosterone production
at the kinds of levels one sees in general population studies.
What about breast cancer, the #1 cancer killer of young women?
Women working in automotive plastics and food canning
are at five times the odds of breast cancer,
suggesting a link, but in a petri dish at least,
phthalates didn't seem to accelerate breast cancer growth
down at the levels of exposure expected in the general population,
but more recently was found to boost breast cancer cell growth
in vitro at the levels found circulating in the bodies of many women.
Therefore the maximum tolerable dose set by governments
should be re-evaluated.
How do you avoid the stuff?
Well when you think plastic chemicals, you think water bottles,
but they appear to only play a minor role—
most comes from the food.
How do we know?
Well if you take people and have them stop eating for a few days,
you get a significant drop in the amount of phthlates
spilling out into their urine.
Fasting isn’t exactly sustainable though.
Thankfully we can see similar drops
just eating a plant-based diet for a few days,
which gives us a clue as to where most phthalates are found.
Although, there were a few cases of spikes within the fasting period
after showers suggesting contamination in personal care products.
So we can counsel patients to reduce phthalate exposures
by avoiding the use of scented personal care products,
soap and cosmetics, since phthalates are used as a fragrance carrier.
Phthalates can also be found in children’s toys,
as well as... adult toys.
On behalf of the Danish Environmental Protection Agency,
the Danish Technological Institute made inquiries about consumption patterns.
To see what kind of exposure one might get
based on worst case scenarios.
Those working behind the counters at sex shops
proved to possess very little knowledge on the material specifications
and so they had to do their own testing.
Turns out that the “jelly” is plasticized PVC -
up to two thirds phthalates by weight.
Though the use of water based lubricants may reduce
the health risks 100 fold,
they still may have the opposite of the intended effect.
Women with the highest levels of phthalates
flowing through their bodies had over two and a half times the odds
of reporting a lack of interest in sexual activity.
And these weren’t women in a canning factory,
but at typical exposure levels in America.