Extinction is a natural process. But scientists point out that humans have sped that process up. A new study maps out the places on Earth where species are in the greatest danger of going extinct. The Great Lakes Radio Consortium’s Rebecca Williams reports:
Extinction is a natural process, but scientists point out that humans have
sped that process up. A new study maps out the places on earth where
species are in the greatest danger of going extinct. The Great Lakes Radio
Consortium’s Rebecca Williams reports:
Conservation biologists are most concerned about endangered animals and
plants that are confined to just one location on earth, such as one
mountaintop, one lake, or one farm.
A new study finds there are close to 800 endangered species worldwide that
are found in single remaining sites.
Taylor Ricketts is the lead author of the study published in the
Proceedings of the National Academy of Sciences. He says historically, most
extinctions have been on islands, but the species at risk now are found more
often on the mainlands.
“And I think that’s because our footprint on the mainlands has just grown,
and our habitat conversion of a lot of these places has intensified so much
that even the not particularly susceptible species are beginning to be
threatened with extinction.”
Ricketts says two thirds of these isolated sites don’t have full legal
protection. He points out it’s hard to protect species that are on land
with competing uses, such as agriculture, timber harvest or houses.
Meredith Buhalis and her daughter Zoe. Meredith's breast milk was tested for PBDEs as part of a study by the Environmental Working Group. (Photo by Meredith Buhalis)
Couch cushions often have PBDEs in them... (Photo by Nicholas Sales)
...and so do TVs. Are there any health effects from being surrounded by these chemicals? (Photo by Craig Young)
Flame retardant chemicals help make our lives safer.
The chemicals are designed to keep plastics and foam from
catching on fire, but the flame retardants are worrying some
scientists because these chemicals are turning up in people’s
bodies, sometimes at alarmingly high rates. The Great Lakes
Radio Consortium’s Mark Brush has more:
Flame retardant chemicals help make our lives safer. The chemicals are designed
to keep plastics and foam from catching on fire. But the flame retardants are
beginning to worry some scientists because these chemicals are turning up in
peoples’ bodies. Sometimes at alarmingly high rates. The Great Lakes Radio
Consortium’s Mark Brush has more:
If you take a look around your house, you can find a lot of things that have
flame retardant chemicals in them. They’re in your television set, the cushions
in your couch, and the padding underneath your carpet. They’re known as poly-bromiated-diphenyl
ethers, or PBDEs. And they’re either mixed in or sprayed on plastics and foam to keep a fire
Five years ago a Swedish study found these chemicals were accumulating in women’s breast
milk. Studies in the U.S. followed, and researchers also found PBDEs in Americans, but at
even higher levels. In fact, Americans have some of the highest levels ever measured. And
over time, the levels have been going up.
(sound of baby)
Meredith Buhalis was one of those people measured in a study by an envrionmental organization
called the Environmental Working Group. Buhalis and 20 other first time moms sent in samples
of their breast milk. When the samples were tested, all of them had some level of PBDEs in
them. Buhalis says when she read the results she didn’t know what to think.
“I guess I kind of read the results and the study was like, ‘Oh, well that sort of sucks.’
I wish I knew more about what that meant. ‘Cause I don’t. You know, they don’t know what
Scientists don’t know how or if the chemicals affect human health. And some scientists
think the government and the chemical companies aren’t doing enough to look into PBDEs.
(sound of typing)
In his office at the University of Texas in Dallas, Dr. Arnold Schecter is working on an
article about the flame retardants. He’s been studying toxic chemicals for more than thirty
years. He and some of his colleagues think PBDEs are a lot like another type of chemical…
“It reminds us of PCBs. PCBs structurally are similar to the PBDEs. So there is the worry,
or the concern, that they may have many, if not all, the toxic effect that PCBs have on humans.”
So far the data on PCBs strongly suggest that the chemicals can cause cancer in humans as
well as other human health effects such as damage to the nervous and immune systems. The
companies that manufacture the flame retardants say it’s not fair to compare PBDEs with
PCBs. They say the chemicals are vastly different.
But no one really knows whether the chemicals are similar in the way they affect human
health. That’s because no one’s studied the human health effects of PBDEs.
“Unfortunately, there are no published human health studies and I don’t believe any have
been funded by the federal government to date. Nor by industry, nor by any foundations,
which is a bit different than the situation with PCBs and dioxins years ago when many
studies were being funded.”
Some animal studies suggest that the chemicals can permanently disrupt the hormone and
nervous systems, cause reproductive and developmental damage, and cause cancer. All that
makes scientists such as Dr. Schecter especially concerned about the most vulnerable
population – developing babies.
Because of the concerns, the biggest manufacturer of these chemicals in the U.S. has agreed
to stop making two of the PBDE formulations that were found to accumulate in people. Great
Lakes Chemical says production will stop by the end of this year. The chemicals will be
replaced with another type of brominated flame retardant.
The Bromine Science and Environmental Forum is a trade group that represents companies
that make the flame retardants. Peter O’Toole is the group’s U.S. Director. He says so
far the amount of chemicals found in people doesn’t concern the companies, but the upward
“And again, it wasn’t of alarming numbers, but the manufacturer was concerned that these
numbers were going up nonetheless. And they thought it was prudent, and they talked to the
EPA and EPA thought it was prudent if there was some sort of mutual phase out of those materials.”
Dr. Schecter says he commends the company for taking this step. But he says even though these
two formulations will be phased out, the flame retardants are already in our environment now.
He says his research has found high levels of PBDEs by wiping the plastic casing on television
sets, and in the dust found in homes. He says what’s in our homes now isn’t going to vanish,
so we need to figure out how the chemicals get into us, so we can avoid potential health problems.
For its part, the U.S. Envrionmental Protection Agency says large-scale human health studies
take a long time to develop. An agency spokesperson says the EPA first needs to learn how a
person becomes highly exposed. After that, they say researchers will be able to ask the question,
“for the highly exposed people, are there any health effects?”
(sound of baby)
That leaves people such as Meredith Buhalis, with a lot more questions than answers.
“We are thinking of having another baby, and I think I would really like to know more about
PBDEs. I think about it when I think about that.” (to her daughter) “Oh thank you. Hi, baby.
The Federal government doesn’t plan to regulate the chemicals anytime soon. But some states
aren’t waiting for more studies. A handful of states have placed restrictions on certain
types of PBDEs. And in other states, legislation is pending.
For the Great Lakes Radio Consortium, I’m Mark Brush.