Plastic packaging is not without its downsides, and if you thought mineral
water was 'clean', it may be time to think again. According to Martin
Wagner and Jorg Oehlmann from the Department of Aquatic Ecotoxicology at
the Goethe University
in Frankfurt am Main, Germany, plastic mineral water bottles contaminate drinking
water with estrogenic chemicals.
In an analysis of commercially available mineral waters, the researchers found
evidence of estrogenic compounds leaching out of the plastic packaging into
the water. What's more, these chemicals are potent in vivo and result in an
increased development of embryos in the New Zealand mud snail. These findings,
which show for the first time that substances leaching out of plastic food packaging
materials act as functional estrogens, are published in Springer's journal Environmental
Science and Pollution Research.
Wagner and Oehlmann looked at whether the migration of substances from packaging
material into foodstuffs contributes to human exposure to man-made hormones.
They analyzed 20 brands of mineral water available in Germany - nine bottled
in glass, nine bottled in plastic and two bottled in composite packaging (paperboard
boxes coated with an inner plastic film). The researchers took water samples
from the bottles and tested them for the presence of estrogenic chemicals in
vitro. They then carried out a reproduction test with the New Zealand mud snail
to determine the source and potency of the xenoestrogens.
They detected estrogen contamination in 60% of the samples (12 of the 20 brands)
analyzed. Mineral waters in glass bottles were less estrogenic than waters in
plastic bottles. Specifically, 33% of all mineral waters bottled in glass compared
with 78% of waters in plastic bottles and both waters bottled in composite packaging
showed significant hormonal activity.
By breeding the New Zealand mud snail in both plastic and glass water bottles,
the researchers found more than double the number of embryos in plastic bottles
compared with glass bottles. Taken together, these results demonstrate widespread
contamination of mineral water with potent man-made estrogens that partly originate
from compounds leaching out of the plastic packaging material.
The authors conclude: "We must have identified just the tip of the iceberg
in that plastic packaging may be a major source of xenohormone* contamination
of many other edibles. Our findings provide an insight into the potential exposure
to endocrine-disrupting chemicals due to unexpected sources of contamination."