KE, RC Voigt, S Thomas, B Lamb, C Urban, T Hassold and PA Hunt.
2003. When Disaster Strikes: Rethinking Caging Materials.
Lab Animal 32:24-27.
to companion paper establishing that
bisphenol A induces aneuploidy even at low doses
here for an explanation of aneuploidy
et al. describe in this paper a laboratory accident that
led to a dramatic new discovery about the harmful effects of bisphenol
A (BPA), the molecule with which polycarbonate plastic is made.
accident occurred in 1998, when a lab technician mistakenly used
an extremely caustic detergent to clean out the water bottles and
cages being used in the laboratories experiments on aneuploidy
following the technician's mistake, the incidence of hyperploidy
shot up dramatically to over 8 times the background rate.
from Koehler et al.
scientists also witnessed a 20-fold increase in chromosomal misalignments
and 4+fold increase in death rate, disproportionately among younger
mice. They also noted increases in reproductive tract tumors which
had been exceedingly rare prior to the accident. Even after completely
replacing cages and bottles, the incidence of aneuploidy and chromosomal
aberrations did not fall back to the low levels prevailing prior
to the accident.
levels returned only after moving the animal colony to a completely
this sort of accident rare? Not according to Koehler et
al. They report that in discussions with colleagues at other
labs they revealed "numerous anecdotal reports of unexplained
changes in experimental results and of rapid, visible changes in
caging materials." Indeed, as this paper was in press waiting
for publication, another laboratory
reported on bisphenol A leaching out of laboratory caging at
levels sufficient to cause an estrogenic response.
is this important? Koehler's report is important for two
it has revealed a hitherto unsuspected cause of aneuploidy, which
is a known cause of a large percentage of spontaneous miscarriages
and birth defects in people. Whether bisphenol A causes aneuploidy
in people has yet to be confirmed, but there is no reason
based on current understandings of the mechanisms of aneuploidy
to conclude that it does not. To the contrary, available
evidence indicates that it does. Exposure to bisphenol A is widespread
in people and experienced
at levels comparable to those that subsequent
work by this laboratory proved were sufficient to cause aneuploidy
in mice. These results thus strongly suggest that the
appropriate public health response would be to immediately initiate
steps to reduce human exposure to BPA.
inadvertent and undetected contamination of this sort in laboratory
experiments is likely to cause many erroneous conclusions, and
in particularly, to create circumstances for false
negatives in the study of environmental toxicants. The result
may be that many experiments have provided false assurances
of safety about the health impacts of contaminants. [For
more on this theme...]
et al. conclude that "the sheer volume of reports
of disrupted experiments, in addition to the results from experimental
tests of substances, such as BPA, that may be released from caging
or other environmental materials, warrants immediate attention by
the animal research community."