Chemicals in sunblock and plants causing a decline in sperm counts and gender bending.

[Guest guest]

Sun block

This is the first study to show that oestrogen-like compounds disrupt the

signalling process, " says Jennifer Fox, one of the research team at Tulane

University, Louisiana.

 

- http://www.newscientist.com/news/news.jsp?id=ns9999641 -

 

19:00 18 April 01

 

Gender-bending chemicals that mimic the effect of oestrogen are common in

sunscreens, warns a team of Swiss researchers who have found that they

trigger developmental abnormalities in rats.

 

" We need to do more tests to see how they might be affecting people, " says

Margaret Schlumpf from the Institute of Pharmacology and Toxicology at the

University of Zurich, Switzerland.

 

Researchers know that chemicals which behave like oestrogen can cause

health problems. They can have a dramatic effect on animals, for example

turning fish into hermaphrodites.

 

Some researchers claim that hormonally active chemicals from the urine of

women taking the birth control pill are already swamping the environment,

and may be causing a decline in sperm counts.

 

 

Uterine growth

 

 

Schlumpf and her colleagues tested six common UV screening chemicals used

in sunscreens, lipsticks and other cosmetics. All five UVB screens -

benzophenone-3, homosalate, 4-methyl-benzylidene camphor (4-MBC), octyl-

methoxycinnamate and octyl-dimethyl-PABA - behaved like oestrogen in lab

tests, making cancer cells grow more rapidly.

 

Three caused developmental effects in animals. Only one chemical - a UVA

protector called butyl-methoxydibenzoylmethane (B-MDM) - showed no

activity.

 

One of the most common sunscreen chemicals, 4-MBC, had a particularly

strong effect. When the team mixed it with olive oil and applied it to rat

skin, it doubled the rate of uterine growth well before puberty. " That was

scary, because we used concentrations that are in the range allowed in

sunscreens, " Schlumpf says.

 

Nobody knows if doses are high enough to create problems for people, says

Schlumpf.

 

 

Low levels

 

 

" Evidence that they're a real health concern is still lacking, " says

Richard Sharpe from the Medical Research Council's Reproductive Biology

Unit in Edinburgh. But he adds, " It's not good news that we are lathering

ourselves with creams with hormonal activity. "

 

The Cosmetic Toiletry & Perfumery Association, which represents sunscreen

manufacturers in Britain, replies that the levels found by Schlumpf are

well below anything that would cause an effect after a single application.

 

A study by the association, not yet published, shows no effect from these

chemicals in rats. But, it adds, " If levels are increasing [in the

environment] then we're aware something would have to be done soon. "

 

 

Breast milk

 

 

That day may be here since 4-MBC and other sunscreen chemicals have been

shown to accumulate in fish from lakes where people swim.

 

More worryingly, they have been found in breast milk at levels of nanograms

per kilogram of fat - about the same as other known environmental

contaminants. Schlumpf worries that the large amount of sunscreen used by

bathers, especially children, could dramatically increase this exposure.

 

Schlumpf says the other 25 or so chemicals used in sunscreens should also

be tested for hormonal activity, and she will be looking more closely at 4-

MBC to see if the offspring of exposed rats develop health problems.

 

For the moment, she isn't advising people to ditch sunscreens completely,

but suggests that sunblocks like zinc oxide might make a healthier

alternative.

 

More at: Environmental Health Perspectives (vol 109, p 239)

 

Correspondence about this story should be directed to

letters

 

Nicola Jones

 

" Gender-bending " chemicals disrupt plants too

http://www.newscientist.com/news/news.jsp?id=ns99991298

 

09:51 14 September 01

 

Oestrogen-like compounds in pesticides, herbicides and pollutants can

disrupt chemical signals in plants, researchers have shown. Knock-on

effects could even be affecting human and livestock fertility.

 

The scientists demonstrated that the chemicals - such as the pesticide DDT

and bisphenol, a by-product of plastic making - disrupt the signalling

between leguminous plants and symbiotic bacteria in their roots.

 

The legumes include soy bean, alfalfa, pea and clover and use the bacteria

to convert nitrogen from the air into a form that can be used in protein

manufacture.

 

" This is the first study to show that oestrogen-like compounds disrupt the

signalling process, " says Jennifer Fox, one of the research team at Tulane

University, Louisiana.

 

It is well established, that oestrogen-like molecules interfere with animal

hormones, but this study opens up a new range of potential effects on the

environment and on crops.

 

 

Impaired growth

 

 

Fox assessed the presence of different chemicals on the activity of the

bacteria's nitrogen fixation pathway. Oestrogen-like compounds caused a

reduction in activity of up to 90 percent.

 

Paradoxically, this might mean that adding certain pesticides and

herbicides to crops will actually inhibit their growth by impairing

nitrogen fixation. Farmers might not notice the effect because added

fertilisers provide an alternative supply of nitrogen, says Fox. " Maybe

people did not get this connection before, " she adds.

 

She suggests that her research might allow farmers to choose pesticides and

herbicides that do not have this effect so that they could achieve the same

yield for a smaller fertiliser input and hence lower cost.

 

Potentially more worrying are possible indirect effects on humans and

livestock. If the signalling process between plant and bacteria breaks

down, the microbe stops converting atmospheric nitrogen. The nitrogen

hungry plant then boosts its own signal production.

 

This, says Fox, might load the plant with natural phyto-oestrogens, which

will end up in the person or animal that eats it. Phyto-oestrogens are

known to mimic some hormones in mammals, including humans, particularly

those related to fertility.

 

John Hillman, director of the Scottish Crop Research Institute in Dundee

says that this is an " interesting idea. " However, he added: " I am not aware

of evidence for a change in the physiological status of the plant, " when

oestrogen-mimicking chemicals are present.

 

 

 

Parting of the sexes

 

http://www.newscientist.com/news/news.jsp?id=ns9999141

12:38 07 November 00

 

Men and women's brains continue to develop differently well into adulthood,

scientists from the Netherlands have found.

 

The region of the hypothalamus studied is related to gender identity -

feeling male or female. It was known to be bigger in men than women, but

the new study shows it only becomes relatively large well after puberty

begins.

 

" The process of sex differentiation extends over a much longer period than

we thought, " says Wilson Chung of the Netherlands Institute for Brain

Research in Amsterdam.

 

Chung and his colleagues compared post-mortem brains from fetuses, infants

and children up to age 16, and adults over 22 years old. They found the

size difference only in the adult group. Chung says the difference may

develop late in puberty, but certainly not at its onset, when you might

expect.

 

 

 

Gender identity

 

 

 

It is unclear why the region changes in size. The area studied is known as

BSTc and is thought to be important in gender identity. For instance, NIBR

director Dick Swaab reported in 1995 that the same brain region in

transsexual men was more typical of the size seen in females than in males.

 

But gender identity is now thought to be heavily influenced by testosterone

levels during fetal development, and is certainly well established before

than the change in size of the BSTc becomes apparent. " Kids and

transsexuals know their gender identity much earlier, " says Chung.

 

His study only measured changes in the volume of the region. There may be

sex differences in biochemistry or connectivity within the area before the

size difference develops. Alternatively, other brain areas might play a

role. But Chung thinks the influence of sex hormones on the structure of

the brain seems to extend into adulthood.

 

This research was presented at a conference in New Orleans, organised by

the US-based Society for Neuroscience. New Scientist's full coverage of the

conference is here:

 

 

 

 

 

 

 

 

[Guest guest]

-

" Elaine " <mem121

<Undisclosed-Recipient:@usermail.com;>

Sunday, February 24, 2002 10:20 AM

Chemicals in sunblock and plants causing a decline in

sperm counts and gender bending.

 

 

> Sun block

> This is the first study to show that oestrogen-like compounds disrupt the

> signalling process, " says Jennifer Fox, one of the research team at Tulane

> University, Louisiana.

>

> - http://www.newscientist.com/news/news.jsp?id=ns9999641 -

>

> 19:00 18 April 01

>

For about 20 years now, I have been using PABA (taken in tablet

form) instead of sunscreen. I used to burn very badly, even though I lived

up North, just by going out & being active. I never sunbathed or slept in

the sun, and I still burned. Since taking PABA daily, I rarely burn. I

just tan. Below are 2 snips about PABA. One a warning about some people

being allergic, and the other a description of its action. From what I

understand, we humans need UV in the near UV range for vitamin D synthesis.

 

Alobar

 

.. . . complaints about PABA being bad for your skin. The main reason for

these complaints is that PABA sometimes causes an allergic reaction in

certain people. These people should avoid contact with PABA

 

PROPERTIES AND USES

 

 

PABA is used as a topical sunscreen, absorbing ultraviolet light of wave

lengths between 190 and 270 nanometers. However, it does not absorb in the

near ultraviolet range, 350 to 400 nanometers,

[Guest guest]

What is a " gender-bending chemical " ? I've never seen a chemical in drag...

 

Seriously, though these studies that attempt to root gender identity in

biology are so hokey given how gender is socially constructed...

 

Ramit

 

At 08:20 AM 2/24/2002 -0800, you wrote:

>Sun block

>This is the first study to show that oestrogen-like compounds disrupt the

>signalling process, " says Jennifer Fox, one of the research team at Tulane

>University, Louisiana.

>

>- http://www.newscientist.com/news/news.jsp?id=ns9999641 -

>

>19:00 18 April 01

>

>Gender-bending chemicals that mimic the effect of oestrogen are common in

>sunscreens, warns a team of Swiss researchers who have found that they

>trigger developmental abnormalities in rats.

 

 

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[Guest guest]

Hi Ramit,

That was cute! a chemical in drag

I believe what they are speaking of is estrogen or progesterone that will

actually make a male into a female, or vise versa, the imbalance may cause much

problems with females and or males that have not been associated with a hormone

imbalance coming from plants or sunblock.

Elaine

-

Ramit

Gettingwell

Sunday, February 24, 2002 4:23 PM

Re: Chemicals in sunblock and plants causing a decline

in sperm counts and gender bending.

 

 

What is a " gender-bending chemical " ? I've never seen a chemical in drag...

 

Seriously, though these studies that attempt to root gender identity in

biology are so hokey given how gender is socially constructed...

 

Ramit

 

At 08:20 AM 2/24/2002 -0800, you wrote:

>Sun block

>This is the first study to show that oestrogen-like compounds disrupt the

>signalling process, " says Jennifer Fox, one of the research team at Tulane

>University, Louisiana.

>

>- http://www.newscientist.com/news/news.jsp?id=ns9999641 -

>

>19:00 18 April 01

>

>Gender-bending chemicals that mimic the effect of oestrogen are common in

>sunscreens, warns a team of Swiss researchers who have found that they

>trigger developmental abnormalities in rats.

 

 

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[Guest guest]

Hiya!

 

>That was cute! a chemical in drag

>I believe what they are speaking of is estrogen or progesterone that will

>actually make a male into a female, or vise versa, the imbalance may cause

>much problems with females and or males that have not been associated with

>a hormone imbalance coming from plants or sunblock.

>Elaine

 

I don't doubt these nasty things forced into our food are having a negative

impact on our bodies, and I do worry about how all these foreign hormones

impact children's development! That said, " gender bending " means something

very different from having sexual developmental problems, so I was just

picking on the article, which I thought was very poorly written. Not

trying to shoot you, oh messenger!

 

Ramit

 

 

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