Sun Block has Endocrine Disruptor Chemicals

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Sun Block has Endocrine Disruptor Chemicals

JoAnn Guest

Mar 22, 2005 13:55 PST

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Sun Block has Endocrine Disruptor Chemicals

New Scientist 18apr01

[Environmental Health Perspectives Abstract below]

http://www.mindfully.org/Health/Sun-Screens-EDs.htm

 

Gender-bending chemicals that mimic oestrogen are common in sunscreens,

warn Swiss researchers

 

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.

 

 

--

 

 

In Vitro and in Vivo Estrogenicity of UV Screens

Environmental Health Perspectives v.109, n.3, Mar01

Margret Schlumpf, Beata Cotton, Marianne Conscience, Vreni Haller, Beate

Steinmann, and Walter Lichtensteiger

 

Institute of Pharmacology and Toxicology, University of Zurich, Zurich,

Switzerland

 

 

--

 

Abstract

Ultraviolet (UV) screens are increasingly used as a result of growing

concern about UV radiation and skin cancer; they are also added to

cosmetics and other products for light stability. Recent data on

bioaccumulation in wildlife and humans point to a need for in-depth

analyses of systemic toxicology, in particular with respect to

reproduction and ontogeny. We examined six frequently used UVA and UVB

screens for estrogenicity in vitro and in vivo. In MCF-7 breast cancer

cells, five out of six chemicals, that is, benzophenone-3 (Bp-3),

homosalate (HMS), 4-methyl-benzylidene camphor (4-MBC),

octyl-methoxycinnamate (OMC), and octyl-dimethyl-PABA (OD-PABA),

increased cell proliferation with median effective concentrations (EC50)

values between 1.56 and 3.73 µM, whereas butyl-methoxydibenzoylmethane

(B-MDM) was inactive. Further evidence for estrogenic activity was the

induction of pS2 protein in MCF-7 cells and the blockade of the

proliferative effect of 4-MBC by the estrogen antagonist ICI 182,780. In

the uterotrophic assay using immature Long-Evans rats that received the

chemicals for 4 days in powdered feed, uterine weight was

dose-dependently increased by 4-MBC (ED50 309mg/kg/day), OMC (ED50 935

mg/kg/day), and weakly by Bp-3 (active at 1,525 mg/kg/day). Three

compounds were inactive by the oral route in the doses tested. Dermal

application of 4-MBC to immature hairless (hr/hr) rats also increased

uterine weight at concentrations of 5 and 7.5% in olive oil. Our

findings indicate that UV screens should be tested for endocrine

activity, in view of possible long-term effects in humans and wildlife.

Key words: benzophenone-3, estrogenic activity, MCF-7 cell

proliferation, 4-methylbenzylidene camphor, octylmethoxycinnamate, pS2

protein, rat, uterotrophic assay, UV screens. Environ Health Perspect

109:239-244 (2001). [Online 28 February 2001]

http://ehpnet1.niehs.nih.gov/docs/2001/109p239-244schlumpf/abstract.html

 

 

 

--

 

 

Address correspondence to M. Schlumpf, Institute of Pharmacology and

Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057

Zurich, Switzerland. Telephone: +41-1-635 5971. Fax: +41-1-635 6857.

E-mail: schl-

Preliminary reports were presented at the 9th Annual Meeting of

SETAC-Europe, Leipzig, Germany, 25-29 May 1999, and at the Third SETAC

World Congress, Brighton, U.K., 21-25 May 2000.

We wish to thank A. Soto and C. Sonnenschein for their valuable help in

establishing the MCF-7 cell system, and J. Ashby and M. Prins for their

advice on the uterotrophic assay.

This investigation was supported by the Swiss Environmental Protection

Agency (Bundesamt für Umwelt, Wald und Landschaft), grants FE/

BUWAL/1999.H.03 and FE/BUWAL/2000.H.04.

Received 22 August 2000; accepted 13 October 2000.

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