The Ministry of Health, Labor and Welfare has been developing
the methodology of screening of tens of thousands of suspected
endocrine disruptors for hormonal activities in order to
establish a priority list for detailed hazard evaluation
studies. It is also engaged in the methodology of the definitive
studies in parallel (see the scheme).
A battery of in silico, in vitro and in vivo tests ((i), (ii)
and (iii) in the scheme diagram) should permit successive
examination of hormonal activities of so many substances.
The priority list may be improved progressively by re-sorting
(e.g. in the order of decreasing hormonal activities) as new
information or screening results are obtained. Additional
prioritization criteria may be introduced, such as production
information, for ordering in a more general viewpoint. The
detailed tests (currently under development) will start from the
top compound in the priority list. The resulting hazard
evaluation, along with evaluation of actual exposure, will lead
to a risk evaluation which will divide the reviewed substances
into what needs risk management and what does not. Appropriate
measures will be taken for the former, while the latter will be
put on hold as long as new findings require reappraisal.
Notwithstanding this principle, the evaluation of hazard,
exposure and risk may be conducted immediately of substances for
which large-scale tests have already made with results
sufficient for the evaluation of hormonal activities, as is the
case for pesticides for which multigeneration tests have been
finished.
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