Translator: Eirian James Reviewer: Sebastian Betti
At home, when we have to store a substance
that's potentially toxic --
I'm talking about an insecticide or a product
designed for pest control --
we take precautions.
We either store it in a shed or in a separate room,
or even on a top shelf,
well marked and out of the reach of children.
However, what if I tell you that every single one of us
without realising it,
has been storing a potentially dangerous substance
in our kitchens for years?
This substance is far more dangerous
for pregnant women and for children.
Furthermore, we often take these substances,
invisible to the naked eye, back and forth our workplace
and they are in contact with our food
and this substance, that some of you are probably still unaware of,
is called bisphenol A.
Bisphenol A is a petrol-based chemical
which is used to make hard plastics like polycarbonates.
Polycarbonates, and bisphenol in particular,
are what give these plastics solidity and transparency.
And it's bisphenol A which is used to make most plastics,
many of which we use to store or preserve food
in our kitchens.
It is not the only place where we can find bisphenol A.
It is also found in the ink in supermarket receipts,
in the inner layer of tins of food
which are painted, or let's say, covered by a film
to stop them from corroding; they are also in containers,
dental fillings and baby bottles.
Bisphenol A weakly binds itself to the plastic
which means that when exposed to heat and detergents
when we clean these utensils, it comes off the plastic
and passes onto the food.
When we heat up food with a microwave for example,
whatever foodstuffs kept in the containers containing bisphenol,
are contaminated and when we consume them
these chemicals enter our bodies.
Once they are inside our bodies,
they act as impostors
imitating the actions of hormones, imitating the actions of estrogens.
Estrogens are hormones that are normally produced in the ovaries,
and less commonly, in the testicles and other glands, such as adrenal glands.
Estrogens are hormones that are connected to reproduction,
and are crucially important to very sensitive
biological mechanisms.
More than one of you will be wondering right now if a chemical substance
capable of blending in with estrogens, imitating its actions and effects,
can alter the process of reproduction,
and experiments confirm this fear.
With the research group of which I am part, we are working on designing
experiments on animal test subjects with the aim of understanding and discovering
what the effects are and the consequences for reproductive health.
What do we know so far about bisphenol A?
We know it's capable of --
Firstly, of all the chemicals considered environmental pollutants,
it is one of the most studied globally.
What do we know? We know that it doesn't behave like a normal toxin.
We all know that with toxins, or at least the idea,
is that the higher the dose, the more profound the effect.
However, bisphenol A doesn't behave in this way.
It is a toxin that can function in extremely small doses,
measured in parts per million, just like hormones.
Supervisory bodies have established doses for bisphenol
that they consider safe.
What is safe? It's a daily dose of exposure
that is unlikely to cause disorders.
However, in our experiments in which we expose newborn female lambs
to bisphenol with the aim of studying them at a later stage,
we find changes in their ovarian function.
This has happened not only exposing them to safe doses,
but also to ones 100 times lower than the safe dose.
Another thing that we know about bisphenol is that it is part of a group of chemicals
whose effect is not seen immediately,
but rather long after the initial exposure.
And when I say 'long after', this can mean that exposure to bisphenol
during the pregnancy or soon after birth
shows its effects weeks, months, years and decades down the line,
long after the moment of exposure.
What is happening?
Just as estrogens normally program reproductive organs
so that in adult life they work correctly,
the interference of bisphenol can cause
what we call a reprogramming of those organs and therefore later on,
in adult life, they won't function effectively,
or will become infected or damaged.
There is increasingly stronger evidence regarding the effects
caused in animal test subjects.
In studying the effects
on the reproductive organs such as the uterus,
we can see that the changes produced later on in adult life
lead to errors in the implantation of the embryo.
In the case of the mammary glands and the prostate, there have been instances
among laboratory animals of precancerous lesions caused by exposure to bisphenol.
In the testicles, there is an immediate decrease in function,
a decrease in the sperm count,
and in the semen quality.
As I've mentioned, we know that there is a change in the ovaries
that could compromise the future fertility of the female
in animals, and probably also in women.
But this is all about animals.
What do we know about its effect on humans?
In human beings, there have been cases of bisphenol being detected in urine,
in blood, in the amniotic liquid that surrounds the foetus, and in milk.
This means that bisphenol is capable of not only penetrating the placental barrier
and pass to the foetus, but also that if a woman has been exposed to bisphenol
she can also pass it on both via breast milk
and through the accumulation of bisphenol in tissue,
which during something as necessary and common as breastfeeding,
can be passed onto the baby.
All these facts are giving us a full overview of the effects
that can be produced in humans, based on tests carried on animals.
Well then, what can we do?
Firstly, and most importantly, I think is to learn more about bisphenol A,
learning by studying reliable information and sharing it.
This will lead to a situation like that of Canada, for example,
who, having looked at studies also carried out in Argentina,
made the decision to ban baby bottles made of plastic,
becoming the first country in the world to do so.
The USA then followed suit, followed by the European Union,
and finally Argentina in 2012, with the aim of minimising risks
that could be produced by the passing of bisphenol
from plastic baby bottles to the baby.
But there are other things that we can do.
First of all, not mixing heat with plastic and foods.
To the extent possible, not to heat food kept in plastic containers
in microwaves.
Another thing would be to use an alternative: ceramic, glass, metal
or simply to empty the plastic container into a plate that isn't made of plastic
and then heat it.
Another recommendation is that people who work as cashiers in supermarkets
use gloves to avoid exposure to the ink on receipts.
There are studies that show that those who work as cashiers
have higher levels of bisphenol in their blood.
There are also studies carried out in fertility centres where it has been noted
that women who are infertile have elevated levels of bisphenol
in the blood.
What else can we do?
As in life, there are options: we can bear this information in mind,
we can ignore it, or we can wake up and take measures of precaution,
such as those that I've mentioned, to minimise the risks of bisphenol exposure.
One such measure can be knowing what we are buying and what we are using
and if we are going to use plastic containers,
we should ensure that we use those of which we are certain that,
dating back to their production, have always been free of bisphenol.
There are such containers in the market, and we should use these
if we decide to use plastic.
Like everything in life, or like many things in life,
we can either worry about it or do something about it.
The decision is for all of us to make.
(Applause)