|Possibility of effects on the growth of the fetus
|On November 2, 2005, Japan's Ministry of Health, Labour and Welfare announced
the result of the deliberation of the Pharmaceutical Affairs and Food Sanitation
Council, calling for attention about guidelines regarding consumption of
16 types of fish containing dimethyl mercury by pregnant women.
We note that different countries have different standards and guidelines for mercury in fish (including dimethyl mercury). There are also different opinions regarding levels in breast milk, as well as countries with guidelines for young children and adults other than pregnant women, which are important areas of concern.
Leading up to this November 2 announcement there was a risk communication
meeting on July 19 of the government's Food Safety Commission. There has
also been an opportunity for the public to make comments to the Ministry
of Health, Labour and Welfare.
|The progress so far
|In June, 2003, the Food Safety Commission announced its first advice (based on a risk assessment/evaluation) for pregnant women on fish consumption concerning mercury contamination. They set the safe levels to 3.4 ƒÊ‚‡ per kg bodyweight per week (1ƒÊ‚‡ is 1/1,000,000 gram).
After this was announced, JECFA, the joint FAO and WHO expert group, also noted concerns reagrding the toxicity associated with mercury. Several other countries then decided to make a re-evaluation of the intake recommendations for pregnant women.
In July 2004, Japan's Ministry of Health, Labour and Welfare asked the
Food Safety Commission to begin a Food and Health Effect Assessment.
|The Food and Health Effect Assessment of the Food Safety Commission
|The special contaminant committee within the Food Safety Commission must
generally consider the food culture of Japan, and in this case especially
take into account the high intake of fish. It is necessary to look at the
epidemiological data of the Japanese citizens at risk as national guidelines
are made. But, in this case such data does not exist, so it considered
data and human cohort studies from other similar countries, such as the
Seychelles and the Faeroe Islands, where much fish is also consumed in
the daily diet.
|(1) The concept of high risk group: The fetus
|It is well known that the fetus is highly sensitive to the influence of
mercury. Since dimethyl mercury almost never moves via the breast milk,
the infant child is less at risk even if the breast-feeding mother eats
fish. In addition, the ingested dimethyl mercury is excreted from the baby
at the same rate as in the case of adults. Thus the possibility of an influence
on the brain development is the reason the fetus is thought to be a high
risk group, which puts the focus on the guidelines on pregnant women and
women who may become pregnant.
|(2) The level of 2.0ƒÊ‚‡ Hg per kg bodyweight as a permitted safe level of
|The JECFA appraisal was based on calculations using research from hair
and blood samples from the Seychelles and Faeroe islands (measuring the
ratio of mercury concentration in hair and blood) as well as data on excretory
|From the contents of Japan's reevaluation
|The Food Safety Commission's Health Effect Assessment and risk communication,
after accepting the public comments, said there was a decision:
"to increase the number of fish on the list of species that should
be restricted to 16 types, including maguro (tuna), for pregnant women
and women who may become pregnant."
In brief, it appears that there are still many unclear points, and a deplorable
lack of data. The Ministry of Health, Labour and Welfare has expressed
that "this data is not final. As we get more information, we will
continue to update the guideline".
Dimethyl mercury has the most toxic effect among the substances known as
organic mercury. In food, most of the dimethyl mercury exposure (84.2%)
is estimated to come from consumption of fish. Certain species of older
and larger fish, as well as carnivorous fish and swordfish, contain relatively
high levels of dimethyl mercury.
In our opinion, it is essential that the government make more and more
use of the precautionary principle to protect citizens, and we will continue
to call for further
research to get more data regarding this issue.
|(Copyright FSCW August 2005)
Food Safety Citizens' Watch
c/o Consumers Union of Japan
75 Waseda-machi, Shinjuku-ku
Tokyo 162-0042, Japan
|Food Safety Citizens' Watch Newsletter