won a Nobel Prize for the important discoveries he and two other scientists
made about the dangers of chemicals to the earth's ozone layer. He was
the first Mexican American to receive a Nobel Prize. Students interviewed
Molina on Oct. 6, 1998.
Were you interested in science when you were young?
When I was in elementary school, I was very interested in science already.
I must have been ten or eleven years old. I started experiments with
chemistry sets at my home in Mexico. I was able to borrow a bathroom
and convert it to a laboratory. My parents supported it. They were pleased.
My friends just tolerated it. It was very thrilling to find out how
nature works. I remember playing with toy microscopes. I discovered
I could see all sorts of life, like a drop of water that had been in
contact with pesticides. I could see all kinds of creatures that were
moving but that seemed invisible.
Did you have any role models when you were growing up?
Not at the beginning but a little later in high school, some of my teachers
were role models. Also, I had an aunt who was a chemist. We did scientific
experiments that went beyond toy chemistry sets. She was a role model
Do you remember the first experiment that you performed?
For the first experiment, I did chemical analysis of stuff around the
house, of whatever I could find. I did it to find out what the chemicals
in it were. Sometimes it turned out to be very difficult. I took cleaning
powder and sometimes food to analyze.
Did your friends think your interest in science was weird?
Initially they did because they thought it was homework. It's not something
that you usually do to enjoy yourself. But I explained to them that
for me, it was very, very interesting, and I had a lot of fun. I think
they understood then.
What qualities do you need to become a scientist?
First of all, you need curiosity. You want to find out how things work.
You also need creativity — to want to find out new things, the things
that are not discovered yet in nature. You have to have patience and
perseverance, and you need to work hard. But perhaps most importantly,
you have to enjoy what you do. Then you will do it very well.
How did you first discover that chlorofluorocarbons (CFCs) were damaging
the earth's ozone layer?
I first just looked at the CFCs, and I didn't know that they were damaging
the atmosphere. The first part of the research was just to find out
what happens with compounds that are not natural. The question was:
How does nature destroy such compounds? The second part of the research
led to the answer. We realized that the CFCs have to go all the way
up to the stratosphere, 20 miles above the earth's surface, and that's
where they will be destroyed, by energy from the sun. Then comes the
last and crucial part. We then found out that when they are destroyed,
they produce chemicals (chlorine atoms) that attack the earth's ozone
How does this happen?
The ozone layer is what protects us from the energy from the sun. In
the lab, we studied what type of energy — what type of light — destroys
the molecules. We found that it's not a light that you can see. It's
ultraviolet rays, a type of light that normally doesn't get to the earth's
surface. The ultraviolet light doesn't reach us because of the ozone
layer's protection. The CFCs travel all the way up to the stratosphere,
to that type of light. Some chemical compounds are very strong. They
are not broken down and destroyed, for example, by rain. So they stay
intact until something happens to them. It takes a long time to reach
the stratosphere, 20 miles above the earth. That explains why they are
destroyed very slowly.
Do most scientists now agree that the CFCs damage the ozone layer?
Yes, most scientists agree, almost all. Practically all of the scientists
who study the atmosphere agree. Some people do not agree, and it's because
they haven't looked at the evidence.
Would volcanic eruptions be the cause of the damage to the ozone
No, it is not possible. We understand very well what volcanoes do. We
can measure it. There was a very big volcano some years ago in the Philippines,
so many experiments were done at that time about what a volcano does.
It was very clear what the volcano does and doesn't do.
Were you frustrated when people did not pay attention to your discoveries
Yes, I was frustrated at the beginning. But it was reasonable. The ozone
layer is invisible, and the CFC gases are, too. The ultraviolet light
is also invisible. So it took a long time for the people in the press
and the public to understand it. Everything seems to be invisible in
this situation, so they didn't understand it. Scientists discovered
that there was a hole in the ozone layer over Antarctica.
Can you describe the hole in the ozone layer?
There is usually quite a bit of ozone, not right next to us on earth,
but far away, miles above the surface. But at the South Pole, when the
ozone hole formed, what we mean by a hole is that the ozone is practically
gone. Of course, there is still air there, but no ozone.
Why did people start using CFCs?
The CFCs were good compounds at the beginning. They replaced some very
nasty chemicals that were used for refrigerators, such as ammonia. The
CFCs did not smell, and they were better. But the CFCs were too good.
They were so strong!
What can an individual person do about the CFCs?
When you repair the air conditioning in a car, for example, instead
of using CFCs, you can use new chemicals. In the classroom, a teacher
can teach that the situation with CFCs is a good example of when people
became interested, they made the government force people not to manufacture
Can we repair the damage to the ozone layer?
Yes, we can repair it. All we have to do is not use the CFC gases any
more, not to manufacture them any more. That is already happening. Also,
the sun creates ozone, so the ozone layer will repair itself. But it
will take many years — 20 or 30 years.
What do you think is the worst threat to the earth's environment?
That's a difficult question, but I can name a few. Global warming is
one. We are adding acids to the atmosphere. That will change the climate
in the world. Another important problem is the burning down of forests
all over the world. This problem is causing many animals and plants
to disappear because we are taking away these forests. There are also
worries about water that we need to grow food. It's polluted in many
Can we find solutions to such big problems?
Yes, we can, but it is not going to be easy. We have a very good example
that this can be done. With the CFC gases, people around the world agreed
to stop making these gases. We know that people have talked to each
other and when there is a will, you can begin to solve these problems.
Do you think people can overcome the greed and solve these big environmental
I am an optimist. I am positive. It's possible to do the necessary changes,
but it's not going to be easy. It will take a lot of hard work. I have
a lot of trust in the children now, in young people. I think they are
paying more and more attention to the problems of our planet. That's
the big hope I have. I think the children can do better than we did.
You are now a professor who teaches.
Why do you prefer to teach now more than be in the lab?
What happens is that I also have students in the labs themselves, so
part of my teaching is working with the students in the lab. Even though
I am not in the lab myself, I work with students who are in the lab.
How can you earn a living as a scientist?
There are different ways. What I do is work at a university. My job
is both to teach and to do research in the lab. The government is another
place to work. There are some laboratories that just do research, like
What kind of education do you need to become a scientist?
The first education to be a good chemist is to do well in high school
science courses. Then, you go to college to really become a chemist.
You want to take science and math. Those are the main things. There
are other things you might want to learn about, such as history and
literature. It helps make you a better member of society so that you
can benefit society.
What kind of things do you emphasize to your students?
I emphasize how science works. You have to understand really the basic
rules of science. I also stress how interesting research in the lab
is, what it's like to find out new things.
What advice would you give to someone who wants to become a scientist?
Today, it would be several things. First would be to read about science
and scientists. Also, I would advise someone not to lose their curiosity.
If something is very interesting, they should keep working at it, and
it will become more interesting. Another thing I would advise is to
find friends who share your interests.
What are your goals now?
I am still doing research, so I want to do even better research. Another
one is to work with my students and to help them become good scientists.
Another difficult goal is to work with governments around the world
to solve these big problems in the environment.
Would you advise a student to try experiments the way that you did?
Yes, I would. There are many more ways to do this. There are excellent
TV programs and very interesting things on the Internet and in museums.
If it is supervised at home, it's safe, and if it's interesting, then
it's okay. I did not play with explosions or anything dangerous. I didn't
have any poisonous chemicals. You can do very safe experiments.
Do you go back to your hometown of Mexico City, and does it still have
a pollution problem?
Yes, to both questions. I do go back, and it does have a big pollution
problem. There are too many cars. You can see it and smell it. The way
you can tell is that you cannot see the mountains around the city.
Is anything being done about this problem?
Yes, but even more needs to be done because it is a bad problem. They
could have better buses and subways, for example, and cleaner cars.
Did you have scientists who were heroes to you, and were any of them
The scientists I looked up to at the beginning were not Latino. They
were famous scientists of many years ago, like Madame Curie. Later,
I realized that there were also, but a very few, Latino scientists.
There were good ones, but very few, because there wasn't as much a tradition
to be a scientist in our culture. But this is changing. Many Latino
kids should become scientists because we need scientists all over the
world from all different backgrounds. We have many tough problems, and
we need everybody's help to solve the problems.
Did it help you to be able to speak both Spanish and English?
Yes, it did. It always is very good to know many languages. As a scientist,
when I am in Latin America, I can speak to the other scientists in my
own language (Spanish). Here in the United States, Latino students also
sometimes speak Spanish.
Do you think there is discrimination in the sciences against Latinos?
There is less and less. The main problem is that we still have too few
scientists from Latino communities and from black communities, not as
many as we would like to have.
How did you feel when you won the Nobel Prize, and did you receive anything
when you won?
I felt very honored and very good. I felt I could be an example of a
Latino scientist. I received some money, and I used some of that money
to support students of Latino backgrounds.
We read that you gave away a lot of the money that you won for the
Nobel Prize to scholars in developing countries. Why did you do that?
Because the problems we are taking about, many of them are stronger
in developing countries. There are already too few scientists covering
the environment in those nations. We cannot solve the problems without
the help from scientists who live in those places.
What do you think is important to learn about the environment?
I think it's important to know how the earth works and how everything
seems to be connected. You cannot damage, for example, the fish in the
ocean without having damage to other parts of the planet. It's important
to take care of all of this, all over the planet.
What do you feel most proud of?
I feel most proud of having uncovered an important problem and that
we figured out how to solve the problem for the benefit of people all
over the world. It's the first example of a global environmental problem
and the first example of a solution to such a problem!
Is there anything else you would like to say to the audience?
If students are interested in science, it can be fun and rewarding.
Also, I would say that a good scientist can do a lot for the world.
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