Yokohama Consensus Statement
the Effects of Endocrine Disruptors in Living Things
Yokohama City University
13 December 1999
Yokohama International Workshop on the effects of Endocrine Disruptors
in Living Things was held with particular focus on effects on human
beings, following the 2nd International Symposium on Environmental
Endocrine Disruptors '99, hosted in Kobe on December 9 to 11, 1999
by Japan's Environment Agency.
Responding to reproductive abnormalities reported worldwide in wildlife
due to exposure to manmade chemicals, the Wingspread Statement was
adopted at the July 1991 meeting in Wingspread, Wisconsin, USA.
This statement identified the need to initiate investigations into
human health hazards caused by endocrine disruptors.
the 1991 Wingspread Conference, there have been several significant
advances in our scientific understanding of endocrine disruption.
It is now clear that exposure is ubiquitous. All humans have been
exposed, to varying amounts.
Laboratory experiments show that exposures have impacts at levels
far lower than had been considered possible in traditional toxicology.
more hormone systems, perhaps all chemically-mediated message
systems, are now known to be vulnerable to endocrine disruptors.
more compounds are now known to be powerful endocrine disruptors.
health effects of concern now include adult impacts of fetal exposure.
Japan, concerned ministries and research institutes have also been
conducting similar investigations since 1997. At the Yokohama Workshop
held on December 13-14, 1999, twenty-five scientists from Japan,
North America and Europe agreed on the urgency of investigations
and actions as follows:
organochlorine chemicals working as endocrine disruptors have
already accumulated in the body and effected the health of some
wildlife species. Appropriate technologies must be developed to
reduce organochlorine residues in the environment and consequently
there effects on wildlife.
research is needed to identify the relationships between endocrine
disruptors and their effects on developmental mechanisms. The
most vulnerable period is in the developmental stage. Effective
dose level and metabolic factors can conceivably vary according
to animal species. Also, studies must be conducted into the species
specificity of their effects.
Further investigations should carried out to clarify the effects
of low doses of endocrine disruptors in organisms. In addition,
it is desirable to conduct wildlife investigations not only at
the individual level but also at the population and community
research must be continued to elucidate under what circumstances
endocrine disruptors pose a threat to human health as well as
to the intellectual development and mental health of children.
Investigations must examine the compounded effects of endocrine
disruptors, as exposure occurs to mixtures of substances rather
than to single contaminants.
human beings are biological in nature, with varying genetic predispositions,
and live in groups of individuals under diverse environmental
factors including residence, occupation, lifestyle, etc., research
must investigate individual variation in susceptibility to effects
of endocrine disruptors. For example, study into the effects of
phytoestrogens would be one such theme because Japanese ingest
large amounts of phytoestrogens.
need to determine an effective dose level and evaluate risks of
endocrine disruptors by studying the relationship between concentration
in the environment and intake. Also, study of methodologies for
risk assessment should be promoted.
Until scientific conclusions are obtained, the "precautionary
principle" should be applied to reduce the release of endocrine
disruptors into the environment and the intake thereof.
problem of endocrine disruptors should be addressed in all aspects
of society. Information disclosure and the creation of educational
curriculums on environmental problems are very critical social
problem of endocrine disruption is a global issue. Solutions will
therefore, of necessity, require international collaboration.
Also, joint multidisciplinary research and conferences on the
international level should be continued in order to promote research
City and Yokohama City University will promote both research and
international conferences on endocrine disruptors. Yokohoma City
University will also open its endocrine disruptor research facilities
to researchers both inside and outside of the country in order
to full utilize the benefits.
We, the participants in the Yokohama
Workshop, hereby agree to this Yokohama Consensus Statement. December