30/08/2005 - Swiss research
has shown that some ultra violet filters used
in sunscreens could be absorbed through the
skin into the body and potentially affect
reproduction.
Every one in Europe – particularly in the
north - welcomes the chance to bask in the
summer sun. And careful sunbathers have followed
advice about using a sunscreen to protect
them against the sun’s rays.
However, now it appears that not all sunscreens
that we rub into our skin are as benign as
we thought. Swiss research shows that chemical
ultraviolet filters used in some lotions have
an oestrogen-like activity and when absorbed
through the skin into the body may affect
reproduction.
Scientists at Zurich University tested ten
widely used sunscreen chemicals and found
that some of them mimicked the female hormone
oestrogen, and interfered with the development
of reproductive organs.
Dr Schlumpf of the Zurich research group
explained the significance of the results
to WWF:
"Fifty years ago chemicals were not
used so intensively. Today they are used a
lot. Endocrine (oestrogen) active chemicals
have the potential to interfere with oestrogen
and its functions in the body. As well as
targeting reproduction, they may affect many
different organs and functions like the skin,
bone density and even the brain".
Sunscreen chemicals absorbed through the
skin?
As part of their research the Zurich Group
devised a test to find out whether these chemicals
could be absorbed through the skin. "We
realised it was necessary to look at the substances
that are put on the skin, as it is living
and such a vital part of the body", said
Dr Schlumpf.
"Information on skin penetration is
not readily available and tests on the protective
effects of sunscreens are usually carried
out on adult, healthy skin. We do not know
how these compounds affect young children’s,
elderly people’s or sun burned skin,"
she added.
Their results suggested that some of the
chemicals were able to pass through the skin.
These findings have since been supported by
Danish research carried out on a group of
human volunteers, where it was found that,
to variable degrees, these chemicals do, in
fact, pass through the human skin.
How has industry reacted to the test results?
The Swiss Society of Chemical Industries is
sceptical about the results, as it says that
industry’s own tests have reached different
conclusions, with regard to the toxicity of
these compounds.
However, the Zurich Group has long-term experience
in developmental toxicology, i.e. the effects
on extremely sensitive developing organisms.
Their findings are also supported by studies
carried out by several other research groups
under the European Commission’s Fifth Framework
Programme on endocrine disrupting chemicals
(EURISKED, CREDO research Cluster).
In an Open Declaration on endocrine disruption
by chemicals, participants at the Prague Meeting
in May 2005 appealed to politicians no longer
to ignore potential effects on humans, but
instead to take precautionary action on reducing
exposures to and the risks from endocrine
disruptors.
Chemicals disturb the entire ecosphere
Scientists are also worried about how these
chemicals affect the environment. "The
chemicals we tested for are not only found
in sunscreens but also in clothing and cosmetics",
said Dr Schlumpf. "These will be washed
away into our sewage system and then find
their way into animals, returning to us via
the food chain. We can no longer distinguish
between ecotoxicology and human toxicology
– they are part of the same process,"
she said.
Is REACH the answer?
REACH will help close the knowledge gap that
we now have on the safety of chemicals which
surround us in every day products but the
current draft falls short of adequately addressing
endocrine disrupting chemicals. A view shared
also by Dr Schlumpf, who stresses that "it
will be important to continuously improve
testing for the proper identification of endocrine
disrupting chemicals as hormonally active
substances would fall within the scope for
authorisation".
Her concern is that REACH could result in
short-term acute toxicity testing, which would
not adequately pick up a chemical’s toxicity
on developing organisms, which is when endocrine
disrupting chemicals particularly exert their
damaging effect. Unfortunately developmental
toxicity tests are expensive and require long
term testing, which would be inconceivable
given the extensive amounts of chemicals to
be tested.
WWF considers that this underlines the urgent
need to develop new innovative test methods,
and to ensure the adequate screening and testing
of chemicals for their ability to disrupt
the endocrine system.
Notes:
• Chemicals in the sunscreens that behaved
like oestrogens in test systems were: Benzophenone-3;
Homosalate; 4 methyl-benzylidene camphor (4-MBC);
Octyl-methoxycinnamate; Octyl-dimethyl-PABA.
• 4-MBC was toxic to reproduction
• People should continue to protect themselves
from the sun, and those who are concerned
about these results should cover up or use
sunscreens with mineral filters.
