Masatoshi Morita
National Institute for
Environmental Studies (NIES)
Persistent Organic pollutants (POPs)
are the chemicals that give rise to adverse effects to human health and wildlife through bioaccumulation/ biomagnification
after discharged to the environment. They appear not only in the local environment
applied but also with global distribution by a long
distance transportation and it is for the reason that they are to be controlled
under the international cooperation program. Twelve chemicals are currently
nominated as POPs at Stockholm Convention which was enacted in May 2004. Reported
adverse effects by these chemicals on wild life have been discussed in a variety
of endpoints and animal species. They include a reduced reproduction, immune
depression, abnormal behavior and others.
12 POPs are all organochlorine
compounds which had been prohibited their use in 1970-1980’s in most of developed
countries and their concentration in the environment seems slowly fallen down.
However they are still detected in high concentration in the animals of the
top of food chain such as birds of prey. The present paper will report current
situation of residue levels of POPs in wild birds in Japan.
Rachel Carson described a strange world
where no birds sing in her book “silent spring”. It was caused by pesticide
contamination as of DDT and other POPs and such effects were not limited in
USA. In this paper, case will
be discussed for reduced population and extinction of endangered species in
Japan. Thyroid hyperplasia currently
seen in cormorants is also discussed in relation to dioxins.
Toxicological study, chemicals
monitoring together steady field observation are necessary to protect wild
animals from such adverse effects. An approach for toxicological bioassay for
birds is also to be presented.