Our concern for toxic substances in the environment
started more than 35 years ago with the publication of
Rachel Carson's book the Silent Spring, (Carson,
1962). We started to develop models of the fate of toxic
substances in the environment more than 25 years ago
(see a proceeding from a conference focusing entirely
on models of toxic substances in the environment,
Jùrgensen, 1984). At the beginning of the eighties the
idea to make environmental risk assessment (ERA) for
toxic substances was launched and it became compulsory
for all new chemicals sold in EU from 1984. It was
simultaneously attempted to develop ERA for the
chemicals already introduced, although it was acknowledged
that this would require a wide span of
years.