Chemistry Reference
In-Depth Information
countries from all over the world. The fi rst meeting
was held in Stockholm in 1970.
The serious problems with the development of
reliable MAC values were also acknowledged by inter-
national agencies like the World Health Organization
(WHO), the United Nations Environment Programme
(UNEP), and the International Labour Organization
(ILO). In a joint venture, they initiated the Interna-
tional Programme on Chemical Safety (IPCS; see pre-
amble to Environmental Health Criteria WHO/IPCS
2006).
The main objective of IPCS has been to carry out
and disseminate evaluations of the effects of chemicals
on human health and the quality of the environment.
Supporting activities have included risk assessment
methods that could produce internationally compa-
rable results. The fi rst Criteria Document was the one
for mercury 1978. One reason why mercury had a high
priority was probably the alarming situation world-
wide due to the effects on humans from consumption
of mercury in fi sh.
The Health Criteria Documents often constitute the
best available information on the toxicology of chemi-
cals. As a rule, they are very valuable, and it is hoped that
the production of documents will continue as planned.
There are, however, examples of intensive lobbying by
states and industrial groups before, during, and after
the preparation of the reports. Because practice has been
to require consensus reports, some Criteria Documents
were very diffi cult to fi nish. The Criteria Document for
cadmium is an example in which such problems were
formidable. The work on this Criteria Document took
approximately 15 years to complete.
The Scientifi c Committee started a series of workshops
and meetings dealing with basic aspects of factors related
to metabolism, dose effects, dose response, and critical
organs for metals. The fi rst of these meetings was held in
Slanchev Briag, Bulgaria, in 1971. It was followed by meet-
ings in Buenos Aires, Argentina in 1972 (TGMA, 1973),
Tokyo, Japan in 1974, and Stockholm, Sweden in 1977.
Results of the consensus reached were published (“Effects
and Dose Response Relationships of Toxic Metals”
edited by G. F. Nordberg and published by Elsevier 1976
and the “Handbook on the Toxicology of Metals,” 1st ed.
1979, 2nd ed. 1986). Several meetings dealt with more
specifi c topics such as developmental and reproductive
toxicity of metals (Clarkson
et al
., 1983) and the role of
carcinogenesis. A workshop on neurotoxic metals was
organized in Brescia in 2006. When there was a need for
information on specifi c metals, we arranged meetings
focusing on single metals, such as arsenic, mercury, cad-
mium, and lead.
As a result of ongoing research and the need for
accurate information the interest in metal toxicology
at the Karolinska Institutet increased. We prepared
independent publications with an international per-
spective for evaluating the health risks of certain
metals. At that time, we already had a close con-
tact with the US Environmental Protection Agency,
which wanted background information for mercury
and cadmium for future Criteria Documents. This re-
sulted in formal contracts, and the resulting reviews
were submitted to the US Environmental Protec-
tion Agency and also published by CRC Press in a
number of monographs:
Mercury in the Environment
(Friberg and Vostal, 1972),
Cadmium in the Environ-
ment
, and
Cadmium and Health
(Friberg
et al.,
1985). It
was also the start of the work for the
Handbook on the
Toxicology of Metals
.
We had been aware for several years of the possi-
ble dangers from the use of methyl mercury. In 1958,
Swedish researchers already demonstrated that seed-
eating birds had high Hg levels in their feathers. Some
years later, it was found that fi sh from several lakes
and rivers had high levels of methyl mercury in their
organs. One major source for the mercury exposure
could be industrial discharge of mercury, but methyl
mercury had also been used extensively over many
years for the dressing of seed.
In Minamata and Niigata in Japan, there had been
two outbreaks of severe poisoning with many fatal
cases and prenatal poisonings. Reliable information
on exposure and dose effect and dose response was
lacking. It became obvious, however, that the source of
the poisoning was fi sh and shellfi sh heavily contami-
nated by industrial discharge of mercury into the local
waters.
We found increased concentrations of mercury in
the blood of Swedish fi shermen, who had extensively
consumed fi sh. The mercury levels were alarming-
ly high, even if no signs of mercury poisoning were
found. Some values later turned out to be as high as
or even higher than the lowest that could be estimated
to have caused symptoms in Japan. It points out that
to get signs of intoxication when exposure is fairly
low, you must belong to a sensitive part of the popu-
lation. Based on an extensive research program with
considerable international aspects, we were able to
produce data that were of value for interpreting the
serious effects in Japan. The report from a Swedish Ex-
pert Group (“Methyl Mercury in Fish,” Berglund
et al.
,
1971) has been used to also evaluate health risks of me-
thyl mercury in other countries.
In Iraq, several hundred farmers died after eating
grain dressed with methyl mercury. The disaster
has been studied in detail by a group from Roches-
ter, New York. Their research program on mercury
is still ongoing, and, in collaboration with Swedish
