The importance of skepticism in science | Joe Schwarcz | TEDxMontreal

Always having been engaged in educating the public about science, chemist Joe Schwarcz discusses the importance of skepticism in science in general and chemistry in particular.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

Thank you. Thank you very much.

Chemistry.

Not exactly what you bargained for, is it?

Because to so many people out there,
it's kind of a dirty word.

Indeed, at the prospect
of chemicals invading your life,

I think sometimes you just want to scream.

And the fact is that we have
an image problem in chemistry, to be sure.

How so?

It's actually a multi-image problem.

There are those people who think
that we're just nerds.

And there are those who think

that chemists are those mad scientists
locked away in a lab somewhere,

just thinking about

what new cancer-causing additive
to unleash on the unsuspecting public.

To many, chemistry
is the work of the devil:

what we do is mix up chemicals,

and those chemicals
are synonymous with toxins.

So people strive to get products
that are "free of chemicals,"

(Laughter)

the most absurd of all expressions.

Indeed, if you buy something
that is claimed to be chemical free,

you're not getting a very good deal,

(Laughter)

because what you're buying is a vacuum.

Not a vacuum cleaner, a vacuum.

That's the only thing -
if you can call it a thing -

that is chemical free.

But people strive
for a chemical-free existence.

They want to bring up their kids
in a chemical-free world.

They want them to play with chemistry sets
that require no chemicals.

(Laughter)

Truly amazing.

You know, it turns out

that a 4% solution of acetic acid
is thought of as a chemical.

But you take that same solution
and you put it into a bottle of vinegar,

all of a sudden, it becomes
a "green" cleaning agent.

Indeed, chemical names turn people off.

Beta-D-fructofuranosyl-
alpha-D-glucopyranoside

I'm sure strikes terror
into the hearts of many people.

It causes panic.

And yet, what you just saw
is the chemical term for sugar.

You cannot tell anything about the safety
or the danger of a substance

by the number of syllables in the name.

The only way that you can tell
is by studying it, testing it.

That's how we accumulate
scientific knowledge.

And that's what we try to do
through my office at McGill,

the Office for Science and Society.

We try to cast a beam of light
into the darkness

to try to demystify science

because, indeed, it is complex

and so many people are bewildered by it.

My specific interest
is the area of chemistry,

which I think should be in the limelight.

Now, I'm fully cognizant
of the fact, of course,

that there are skeletons
in the chemical closet.

Certainly, historically,

we have not always
dealt properly with chemicals.

Indeed, chemicals in the wrong place,
at the wrong time, with the wrong dose

can be a huge problem.

We have not always disposed
of chemicals in a proper way.

But the fact is that
this science of ours, chemistry,

is the thread that ties
all of the other sciences together.

If you know something about molecules

and how they interact,
what they can and cannot do,

you get a pretty good idea

of what can and cannot
happen in the world.

Indeed, chemistry
is the fabric of our life,

both figuratively and realistically.

It is the stuff that puts
colour into our life.

It is useful.

You look under your sink,

you will find all kinds
of cleaning agents.

Well, what are they?

It's just a collage of chemicals.

Open your medicine cabinet.

That mix of chemicals, we call drugs.

You look down at your dinner table,

and the food is nothing other
than a very, very complex mix

of hundreds and hundreds and hundreds
of different compounds.

In fact, there are some
60 million known chemicals

that are listed in chemical abstracts.

Most of them, of course, occur in nature.

Some are synthetic.

But whether something
is synthetic or natural

does not determine its impact

on our health or what happens
in the human body.

The body does not distinguish by ancestry.

So we have about 60 million
known compounds.

If you sniff your cup of coffee,

what you're smelling, believe it or not,
is roughly 1,000 different compounds.

It's amazing that we've been able
to determine this.

Many of them, in fact,
have been categorized.

Some of them are known carcinogens,

and yet we know that coffee
does not cause cancer.

If it did, we would know.

There's enough epidemiological evidence.

There are enough people
in the world drinking this stuff

to know what it can and cannot do.

So how is it that there are
carcinogens in there,

but the whole mixture is not carcinogenic?

Well, obviously, because the carcinogens
are found in very small amounts,

and furthermore,

some of the other antioxidants
that are present in the coffee

mitigate the effects
of the more problematic compounds.

So, indeed, we live in a very,
very complex chemical world.

And we put those complex chemicals

into the most complex machine
that exists on the face of the earth,

which is the human body.

It's a huge chemical container.

I know that people think

that chemicals are only to be found
in test tubes or in Erlenmeyer flasks.

But we are nothing more
than a large bag of chemicals.

Hundreds of thousands
of different compounds.

And the fact is that chemicals
are not to be feared or worshiped.

They are to be understood.

They are just things.

They are inanimate.

They don't make any decisions.

We do.

Let me give you an example.

Ammonia - a pretty simple molecule

but one of the most
interesting molecules that exists.

It has changed our history.

Ammonia can be used as fertilizer,

first developed by Fritz Haber,
a German chemist.

It gives amazing improvements
in yields on agricultural fields.

It allows us to feed millions of people.

The world would not be the same
without ammonia.

But let me open up a can of worms here.

Or, in fact, let me defer to Jamie Oliver,

who does that all by himself very well -

opens up numerous cans of worms.

For those of you not familiar with Jamie,

he's a celebrated British chef
who has come over to America

to change the eating habits
of North Americans.

To tell you the truth, I like Jamie.

He pushes fruits; he pushes vegetables.

I like his theory.

His approach is a little bit questionable.

Not long ago,

on his celebrated TV program,

he introduced us to pink slime,
which is neither pink nor slimy.

What it is

is meat that is taken off the bone

after everything else has been cut off
through a mechanical process.

In fact, it is mostly muscle meat,

but then it is treated with ammonia gas

to make sure that there are
no bacteria cruising around.

Well, he introduced this idea,

and he wanted to demonstrate
the nefarious nature of ammonia

as it is being used in this process.

So he opens up a cupboard, the back,

and he takes out a bottle of ammonia
festooned with a skull and crossbones.

Now, I've spent my life in chemistry,
in many laboratories around the world.

Never have I seen a bottle of ammonia
that had the skull and crossbones on it.

In fact, you can go looking
in supermarkets and hardware stores,

or you can cruise the web.

You will not find a bottle of ammonia
that has a skull and crossbones.

So that, of course, was made
specifically for the show

for the dramatic effect.

And then Jamie goes
and takes that bottle of ammonia

and sloshes it all over the meat.

This is not the way that it is done.

Ammonia vapour is used in the process
of producing that so-called pink slime.

Well first of all, there's nothing
dangerous about ammonia vapour.

Ammonia is used in our food supply.

It's used to make cookies -
causes them to rise.

In fact, ammonia can even be used
in cough problems.

So it's not inherently dangerous.

Of course, all chemicals can,
in some way, be a problem.

It depends on how you use them,
what the conditions are

and, of course, how much
of the chemical is used.

But the way that Jamie portrayed this,

it was certainly enough
to frighten people,

to have people demonstrate in the streets

to stop pink slime.

Now, I don't want you to get the idea
that I'm a pusher of pink slime.

I'm not.

But it is not a toxic substance,
the way that it was portrayed.

And in fact, it is probably leaner

than the rest of the meat
that is in the hamburger.

It also allows the meat industry
to use the cow more efficiently.

Now, you would think
that cows would be happy

at the prospect of having this pink slime
be taken off the market

as many fast-food producers have done
in response to this.

Well, no, that isn't exactly true:

the cows are not
all that happy about this,

because about 1.5 million more cows

are going to sacrifice
their life, annually,

to compensate for the meat
that is not being taken off the bone.

So you have to look
at the whole situation.

It is so easy to make people paranoid

by nitpicking and by,
essentially, misleading them

by taking segments of information
which aren't the totality,

which are not completely correct.

Now, I'm not a pusher of pink slime,
and not even of meat.

I think in North America
we eat too much meat.

I think we should cut down
on the amount of meat we eat.

We don't need the gigantic hamburgers.

I've always pushed fruits and vegetables.

We have plenty of epidemiological evidence

that people who eat lots of fruits
and vegetables are healthier.

So that's not why
I pick a bone with Jamie.

It is because
he misrepresents the science.

There is nothing toxic
about this business of pink slime.

It is possible to portray almost anything
as if it were dangerous,

even our fruits and vegetables.

Take an apple, for example.

Or better yet, take a bite
out of that apple.

You know what you're tasting?

You're tasting
over 300 different compounds.

Those are not additives;
they're not pesticide residues.

Those are the building blocks
of that apple.

That's what it's made up of.

Some delightful things.

Acetone.

Well, the last time you encountered it

was probably on the label
of your nail polish remover,

right above where it says, "Do Not Drink."

(Laughter)

There's also some
formaldehyde in that apple.

That's embalming fluid.

That's the stuff that is used
to preserve dead bodies -

it's not what people want
in their live bodies!

Well, here we have
an apple that has acetone.

Acetone is highly toxic.

In fact you could put
a skull and crossbones on it.

So what happens if you eat an apple?

Are you going to be poisoned
by the acetone?

Well, it's okay, because there's also
formaldehyde in there.

So if you go,

it's an economical way to go
because you'll be pre-embalmed.

(Laughter and applause)

Well, of course,
it's absurd to suggest this

because as we understand,

the amount of acetone and the amount
of formaldehyde in the apple is trivial

in comparison to valuable vitamins
and polyphenols that we have in there.

Numbers matter.

There are no safe substances,
only safe ways to use substances.

Five hundred years ago,

Paracelsus, the great alchemist,
philosopher, physician,

told us, "Sola dosis facit venenum."

For those of you who have
forgotten your Latin, let's translate:

"Only the dose makes the poison."

Amounts matter.

You know that aspirin
makes a headache go away.

How much?

Take an aspirin tablet, lick it;
your headache will not go away.

Take two tablets, swallow them;
your headache will go away.

Take the whole bottle, swallow them;

you will go away.

(Laughter)

Only the dose makes the poison.

However, it is also important to realize

that sometimes that dose
can be very small.

We have to look at numbers.

For example, the chemical
that you have heard a great deal about

called bisphenol A -

it's been in the news extensively.

This is the stuff that can leach
out of canned foods

from the epoxy resin that lines the food,

protecting the can
from interacting with the food

and vice versa.

Well, bits of bisphenol A,
very small doses, do leach out.

And they do end up in our body.

In fact, we can detect them in our urine.

The problem is that this chemical,

bisphenol A,

is referred to as an endocrine disruptor.

It can interfere with hormones.

Anything that interferes with hormones
should raise the flag of alarm.

So this has been extensively investigated.

We don't have a final answer.

Science rarely gives us a final answer.

It's a bizarre compound because it seems
that the dose response curve is strange.

Usually you expect toxicity
to increase linearly with dose.

It seems that in the case
of hormonal compounds,

that's not what happens.

So that even at very small concentrations,
you can have significant effects.

In fact, you can have a beneficial effect.

Then you decrease the dose,
you get a detrimental effect.

I mean, this is a most unusual thing.

So bisphenol A has to be
further investigated

because this concept,
which we know as hormesis,

is relatively new in science.

Toxicology is a very complex business.

But there are many, many
other things in life to worry about

than the trace amounts of bisphenol A
that end up in our body.

People drive without seat belts,

they smoke,

they lie out in the midday sun.

Those are far, far more worrisome things
than the trace amounts of bisphenol A.

Life is full of risks.

We can't get away from it.

You can be out for a casual walk,
and horrific things can happen.

(Laughter)

Oh, don't worry, we're nice people.
We faked it. They're fine.

But they're not the innocent,
little creatures that you think they are.

(Laughter)

So there is risk everywhere.

We live with the presence of risk,
especially with chemicals.

But the presence of a chemical
does not equal the presence of risk:

it depends on amounts.

Today, with our modern,
analytical techniques -

our gas chromatograms,
our mass spectrometers -

we can detect substances
down to levels of parts per trillion.

That's one second in 32,000 years.

That's not finding a needle in a haystack;

that's finding a needle
in a world full of haystacks.

And while you're rummaging around
in that haystack,

you might encounter some mold.

That will produce
some really toxic substances,

even though it's natural,

because natural does not equate to safe,
and synthetic does not equal dangerous.

That is one of
the biggest myths out there.

You cannot tell anything about
the potential toxicity of a substance

by its ancestry.

The only way we know if something
is dangerous or not is by studying it,

by looking at its molecular structure,

by analyzing it,

by carrying out chemical reactions,

by studying it in animals.

But high-dose studies in animals
do not necessarily reflect on humans.

The human is not a giant rat,

with some exceptions obviously.

(Laughter)

So one has to be very careful

because even in closely related species,
there are tremendous differences.

Dioxin - widely talked about

as the most toxic substance
known to mankind, which it may be.

It's never produced on purpose.

It's always a by-product
of some industrial process,

but it is in our environment.

It is indeed the most toxic substance -

if you're a guinea pig.

But if you're a hamster,
you can practically frolic in it.

So here we have
two very closely related species,

and yet the toxicity profile
is dramatically different.

And then we come to people.

We can't even really relate
between animals in terms of toxicity.

How can we use animals
to predict what will happen in humans?

We can't really, but it's the best guess,
because we can't do human studies.

But where we really run into problems

is predicting what
will happen in children.

Why? Because a child is not a small adult.

Their body chemistry is very different.

So we have to be especially careful

when we expose children
to chemicals like endocrine disruptors

because they may not be
at all harmful in adults,

but they may play a role in children.

Unfortunately,

we are surrounded by risk, as we said.

You cannot get away from it.

You may replace one with the other,

but if you're not careful,

the replacement may turn out to be
more dangerous than what you're replacing.

So when we think about replacing
bisphenol A with some novel entity,

we had better make sure

that what we're introducing
into the marketplace

is better and safer
than what we are replacing.

Of course, there will be
diverse opinions on all these things.

That's the way science works.

People read the literature,
they do experiments,

they come to various conclusions.

Not always the same conclusion.

No matter what you look at,
there are always varied opinions.

However, they rarely have equal weight.

When you look at global warming,
you look at endocrine disruptors,

you will have the majority
of the scientific community on one side

with some outliers on the other side,

but very often the outliers
are far more vocal

and make for a very seductive case.

But in the science world, of course,
we go by peer-reviewed literature;

we go by experiments.

We don't cherry-pick data.

But unfortunately,
pseudoscientists very often do.

And these days, there's so much published

that you can, basically, find some proof
for any idea that you may have.

However, when you practise
scientific methodology,

you don't cherry-pick;

you shake the whole cherry tree
until all the cherries come down,

and then you mix them together
and mash them up,

and then you taste the evidence.

And hopefully, then,
you don't get into a jam.

(Laughter)

That's what the scientific method

is all about:

weighing the risks versus the benefits.

But in order to do that,
we need some foundation.

We need some basic
understanding of science.

So that's why I'm a big promoter
of education early on.

We need to improve scientific education
in elementary schools.

It is as important
to be scientifically literate

as to be literate in any other area.

And we have to pursue
this scientific literacy,

no matter how hard that may be.

We have to make sure

that we eventually have an educated,
scientifically literate public.

Because all the technological
decisions that we make

are based upon some
sound understanding of chemistry.

It's not that we should be out there
cheerleading for chemistry.

That's not the idea at all.

What we need to do
is come to some rational evaluations,

make sure that people understand

that chemicals are not substances
that should be locked away.

Neither should they be glorified.

They should be understood,
and put to good, intelligent use.

That's what we try to do today
under the umbrella of green chemistry.

We have a large pedestal
of information today on which to build.

We know toxicity profiles of chemicals.

We know what we should choose
as raw materials.

We know how to make reactions
more and more efficient.

Chemistry is evolving all the time.

We're getting better at predicting
what is going to happen

when we engage in this -

what I think is a magical undertaking.

Not everyone shares my view.

There are those who think that chemists
are different from any other species.

But hopefully,

I've been able to demonstrate to you
that that isn't the case,

that we do have some humanity.

We do look at the world
in terms of molecules

and what they can and cannot do.

It doesn't mean that we can
answer all questions.

No, we can't.

We have our limitations.

The world is very complex.

Those 60 million chemicals
engage in all kinds of reactions.

And it is quite possible
that there are questions

to which we will never have the answer.

But we try.

(Laughter)

We try to find the answers,

and that is just what we do
through our office at McGill,

which is a rather unique enterprise.

We are next week relaunching
our website under a new URL.

It is going to be better and more engaging
than it ever has been.

And you can also follow us on Facebook
and follow us on Twitter,

and whenever you have any questions,
feel free to address us.

That's why we are there.

We hope to try to demystify your life

and show you that indeed
there is a little magic in chemistry.

Thank you.

(Applause)