We would be in the trees. Just climbing trees and having fun
and the plane would come over and just spray us.
It was crazy.
This is my mother, Tina, and my aunts Pam, Peach, and Trudy.
They grew up in the fruit-producing valley of Cashmere, Washington.
They spent their days running barefoot through orchards
and on some days, through heavy sprays of the insecticide DDT.
On certain mornings you would smell and you knew they were spraying somewhere.
It was a white residue. And you could definitely taste. Even after you wiped it off, you could taste.
We were riding our bikes, and a neighboring orchardist just came around the corner with his sprayer
and just sprayed right across the road!
Doused! We were wet!
My mom and aunts grew up in the 1950s and 60s
times of heavy DDT use in agricultural fields across the U.S.
At the time, they didn’t consider the chemical to be dangerous.
But now, 50 years later each one of them has been diagnosed with breast cancer,
despite not having any known genetic marker for the disease.
So what could have caused their cancer?
That’s the question that brings them back to the orchard
and the chemicals they were exposed to as young girls.
DDT’s story begins in World War II.
American soldiers fighting in the Pacific Islands used the insecticide to prevent diseases like malaria.
When the war ended, DDT manufacturers found a new market:
Instead of bombs, the B25 now sprays DDT
At its peak, the US was producing nearly 100,000 tons of DDT every year.
If you were alive at the time, you were probably exposed.
And then this happened: It's the 1962 book Silent Spring.
It’s a critical look at American pesticide use.
And it’s credited with kickstarting the environmental movement.
In the early ‘70s, the EPA banned DDT.
Their reasons were mostly based around threats to animals and ecosystems.
But their ruling also hinted that there could be some kind of link to cancer.
I went back for my high school reunion in 1971
and already I was hearing a number of cases of cancer then.
And actually a number of people had died by that time.
But I still, at that point, didn't associate it with the DDT and in what was happening in the valley.
For years, scientists had trouble finding a concrete link between DDT and breast cancer, too.
Until the early 2000s, when a group of scientists looked at frozen blood samples
from the peak of DDT era.
During the ‘50s and ‘60s, doctors at the Kaiser hospital in Oakland collected and froze
blood samples of all the women who came in for pregnancy care.
Now, it’s a library of blood samples from 15,000 women, that like my mother and aunts
were exposed to DDT.
So the researchers tested the blood samples,
and they also looked at the age each woman was first exposed to the chemical.
They found these women, who were exposed at specific ages, had a way higher risk of developing breast cancer.
These are called windows of susceptibility:
Let’s imagine a chemical that causes cancer by messing with the hormone system.
That chemical is going to be more or less toxic, depending on how many hormones are available.
So you get these windows of time
in utero, as a baby, puberty, pregnancy, and menopause
where a toxic exposure might be more likely to cause cancer.
In the DDT study, they found that a woman exposed to DDT
during one of these windows, from the womb to puberty
had five times the risk of developing breast cancer.
I was pretty much exposed since I was a baby.
Well, mom was pregnant when you and Trudy and...
Well, all of us! Hello!
And the impact of that exposure goes beyond one generation.
Researchers followed up with the daughters of the women in the study.
The women whose mothers had high DDT levels while they were in the womb
also had a high cancer rates.
Now, the researchers are looking at the third generation: the granddaughters.
If you were in utero or an ovum in 1960 you're in my cohort.
I'm looking at a joint exposure of three different generations.
The mother, the embryo, and the egg that will become generation three.
And that's most of the world.
Even though this study can’t say whether or not DDT caused their cancer,
it does give my family some sort of closure.
Up until now, individual behaviors have been the primary focus of cancer prevention.
You're too sedentary. You're too fat. You smoked. You drank.
You didn't have your babies early enough. There's a long, long list.
I never can know exactly why one individual woman got their illness,
but trying to put their illness in perspective, that they don't have to blame themselves,
and that there may be multiple forces converging to cause their cancer,
really is, I believe, could be freeing.
It’s not a way to cure cancer, but that knowledge can help
me, my sister, and my cousins come to terms with it our risks
and guide us in understanding and preventing future incidents like this from happening.