Scientists are continuing to sound the alarm about some common chemicals, including the herbicide atrazine, Homosexuality is found in over 450 species snopes link them to changes in reproductive health and development. Endocrine disrupting toxic chemicals have been found to feminize male frogs and cause homosexual behavior.
Ashley Ahearn reports on how these substances may be affecting human development and behavior. We use synthetic chemicals for everything from plastics to pesticides. They eventually make their way from our farms, households or industry into the environment — and into our bodies.
And they may be affecting our reproductive health — indeed, even our sexual preferences. Producer Ashley Ahearn reports. Tyrone Hayes peers into a large gray fiberglass tank like a little boy looking for critters in a tide pool. Below the surface, fat greenish-yellow frogs swim around— their bulging eyes looking up at us through the water. So in this tank there are 40 brothers that are not exposed to atrazine and in this tank there are 40 brothers who were exposed to atrazine and so we can compare these two tubs and look at the number of homosexual pairs.
Once Hayes heard about this he started collecting data. He exposed some of his frogs
Homosexuality is found in over 450 species snopes the same level of atrazine that the Environmental Protection Agency says is safe for drinking water, and he kept the rest of the frogs atrazine-free. Homosexual behavior has been recorded in over different species of animals — from bison to beetles.
This is an animal that looked like a female on the outside. But on the inside it had large testis, so these are testis, and this is an oviduct.
So, this is the equivalent of a man with a uterus. Let me say that again: And there are consequences. And more male frogs means fewer babies down the road. Hayes says this might be one reason that populations of frogs and other amphibians all over the world are going down. In our work with frogs for example we can go into the field.
Studies on rats, reptiles and even human cells exposed to atrazine showed similar results. Recently, scientists with the U. Geological Survey found intersex fish in one third of the waterways they tested across the United States. And atrazine is not the only chemical to blame for causing widespread reproductive health problems.
If you go to your kitchen sink and under your bathroom sink and look at the cleaning compounds that are there. The endocrine system is made up of a series of glands throughout the body that control the hormonal messages that direct development.
By imitating natural hormones— such as estrogen and androgen — endocrine disrupting chemicals prevent the body from sending and receiving those messages.
Stephen Rosenthal, a pediatric endocrinologist at the University of California San Francisco, broke down some basic human developmental biology for me. He says in the womb, we all start out developing as girls.
It tells your gonads to become testis, instead of ovaries, and to start producing testosterone and androgen. Those hormones then travel through the body and hook up with receptors in cells. That sets off a chain of events inside a cell. Now picture some chewing gum in the ignition. I go, yeah but look, the estrogen that works in this frog is exactly, chemically exactly, the same as the estrogen that regulates female reproduction.
So, what about us? Could endocrine disruptors be having feminizing effects in humans? No one knows for sure, but some believe that rising rates of one birth defect could be an indicator. Baskin specializes in correcting hypospadias — the second most common birth defect the country behind heart disease.
Baskin and others in his field suspect environmental exposures may contribute to hypospadias. Think back to the gummed up lock and key that Stephen Rosenthal described.
Endocrine disrupting chemicals, like atrazine for example, could gum up the receptors for those hormonal Homosexuality is found in over 450 species snopes that tell a fetus to develop into a baby boy— or as Baskin explains — prevent the fetus from fully masculinizing.
Ok, so if Tyrone Hayes is finding feminizing effects in frogs who are exposed to atrazine — one of these environmental toxins that Baskin is talking about — are there some parallels to be drawn in human beings?
Baskin pauses for just a split second before responding. Humans clearly are not frogs, but the theory is correct. And in this case we would agree with Dr. Hayes that an environmental disruptor, something in the environment, chemical toxin or medication could certainly be a risk factor for Hypospadias. Baskin says the majority of hypospadias can be fixed with a relatively quick surgery that can make life a lot easier for the child later on.
One of my earliest memories is of being in a hospital and dealing with some physician taking bandages off of my genitals and watching my parents respond in obvious fear about whatever it was that this guy was doing.
I was probably maybe three. But I had my first surgery when I was three "Homosexuality is found in over 450 species snopes" old and I had at least one surgery every year after that until I was at least Devore was born with severe hypospadias. However, the Hypospadias and Epispadias Association — a group which works to raise awareness about these two similar genital conditions - conducted an online survey of roughly men — both with hypospadias and without.
The survey found that men with hypospadias were 15 percent more likely to describe themselves as gay. I told Devore about Tyrone Hayes — the biologist at Berkeley with the homosexual and feminized frogs — and I asked him what he thought about those findings in relation to people.
He said the connection makes sense…. Tyrone Hayes' at work in his lab in Berkeley Photo: Devore says there's a whole lot more to someone's sexual orientation than the chemicals they may have been exposed to during development. This is about who you fall in love with. This is about a whole complex set of social factors. He gets a spoon to mush Homosexuality is found in over 450 species snopes melted chocolate chips around, and comes back out to sit with his mom and me at the kitchen table.
I mean, I talk to him about it personally. Since her son was born, Alice has worked to raise awareness about hypospadias. She also counsels mothers of kids with hypospadias. But she says more attention needs to be paid to figuring out what causes this condition, and communicating that information with the public.
Talking Homosexuality is found in over 450 species snopes problems with reproductive health is something society has never handled well. And perhaps because most hypospadias can be corrected with surgery, very few doctors have raised questions about the underlying causes of this birth defect.
But endocrine disrupting chemicals show up in almost percent of the population, according to the Centers for Disease Control, and many of these chemicals are known to disrupt normal reproductive system development in animals - think back to Tyrone Hayes' frogs here. So I asked Dr. Theo Colborn, who's been studying endocrine disruptors for over 30 years, if she thought our environmental exposures could be affecting our reproductive health. It's one thing to say that exposure to endocrine disrupting chemicals may contribute to hypospadias.
It's quite another to say that a person's sexual orientation could be shaped, in part, by their environmental exposures. That, Colborn says, is an explosive issue. No one wants to touch that research. I mean, you would be laughed out of your chair, believe me. Sensitive, and therefore still very early in terms of scientific findings and evidence. But important questions are now being raised. What effects might chemicals in our environment — particularly those to which we are exposed before birth — have on our reproductive health and the expression of sexual identity?
A study that looks at hypospadias and endocrine disruptors. Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses.
Feminization of male frogs in the wild. Donate to Living on Earth! Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service.
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