1 April 2003
linked to mouse genetic damage
By Alex Kirby
mice have suffered genetic damage from a compound used in many household
items, US researchers say.
compound, bisphenol A (BPA), is used for making some plastics and
resins, food packaging, and dental sealants.
exposed mice showed increases in meiotic errors - the flawed division
of reproductive cells.
researchers believe BPA is a potent meiotic aneugen, a substance
that affects the number of chromosomes, the structure into which
DNA is bundled.
team, headed by Dr Patricia Hunt of Case Western Reserve University,
describe their work in Current Biology.
found BPA, a manmade compound which in the body has hormone-like
properties that mimic the effects of natural oestrogens, could cause
meiotic aneuploidy in female mice.
is the division of a cell producing eggs or sperm in which the nucleus
splits twice, resulting in four sex cells each possessing half the
number of chromosomes of the original cell. It is characteristic
of organisms that reproduce sexually.
is the gain or loss of individual chromosomes from the normal set.
is used in the manufacture of polycarbonate plastics and epoxy resins,
in food and drink packaging, often for lining cans, and in dentistry.
Hunt and her colleagues were studying mice in an unconnected piece
of research when they noticed a sudden increase in meiotic errors
in the animals, including aneuploidy.
showed this coincided with the inadvertent exposure of the mice
to a source of BPA in their laboratory housing, damaged caging material.
team spent several years checking if this really was the cause by
deliberately damaging cages and water bottles, and then giving the
female mice daily oral doses of BPA.
say: "Our results demonstrated that the meiotic effects were
dose-dependent and could be induced by environmentally relevant
doses of BPA.
results provide the first unequivocal link between mammalian meiotic
aneuploidy and an accidental environmental exposure.
have observed meiotic effects in mice at exposure levels close to
or even below those considered 'safe'.
recent study of pregnant women and their foetuses conducted in Germany
suggests that current human exposure levels may well be within this
possibility that BPA exposure increases the likelihood of genetically
abnormal offspring is too serious to be dismissed without extensive
Soto is professor of cell biology at Tufts University medical school,
US. She told BBC News Online: "First, anyone else using similar
cages may be producing totally spurious research results.
that, this is one more piece of research - and an important one
- that adds to the picture we've built up.
already found evidence that BPA can damage the mammary, the uterus
and the male genital tract in lab animals.
research shows it alters reproductive cells both in foetuses and
in adult animals. It's a finding that could be significant for human
Thomas, of the BPA industry group, told BBC News Online: "Some
powerful studies have looked for possible effects of BPA, like miscarriages
or litter size in animals, and haven't found them.
have a high level of confidence these initial studies don't translate
into the postulated effects in real animals.
we don't think this adds to concerns anyone may have about possible
effects of BPA on human health."
Lyons, toxics science and policy advisor to WWF UK, told BBC News
Online: "It looks as if the smoking gun on bisphenol A is now
Taylor of Friends of the Earth UK said: "This research adds
to our concerns about BPA and reinforces our view that it should
be phased out and replaced with safer chemicals."