June 23, 1999

Editorial:Japan needs pre-emptive measures to battle dioxin

After their meeting Monday, advisory panels of the Health and Welfare
Ministry and the Environment Agency released a report recommending that
the maximum
tolerable daily intake of dioxin be lowered to 4 picograms per kilogram
of body weight. A picogram is one-trillionth of a gram. The figure is
considered the largest
permissible amount of dioxin that can be ingested throughout a lifetime
without causing any serious ill effects.

The new number will serve as a basis when the government takes measures
to fight the toxic substance.

The World Health Organization lowered its figure from 10 picograms to 1
to 4 picograms last year. The Geneva-based body explained that 4
picograms is the
maximum permissible amount "for the moment" and less than 1 picogram is
the "target for the future."

Japan adopted the maximum figure as the permissible amount and ignored
the target figure.

The conclusion of the meeting cited an experiment on animals that said
the harmful effects from less than 4 picograms of dioxin was "not
sufficiently reliable." But the
experiment said "some delicate effects" are discernible.

Why then didn't the advisory panels adopt the target figure as well as
the maximum number?

Currently, the average intake of dioxin by a Japanese person per
kilogram of body weight is said to be 2.6 picograms. Government
officials have already said in
private that most people ingest lower than the maximum permissible
amount of 4 picograms.

Against such a background, the new figure of 4 picograms could be taken
as a stamp of approval of the present situation. However, the government
should not
relent in its efforts to reduce dioxin emissions by accepting the new
figure as the standard.

Obviously, the new number is smaller than the current figure of 10
picograms. So the first thing the government should do is strictly
tighten the dioxin-emission
standard at waste incinerators.

The temporary standard, which is to be applied to existing incinerators
until November 2002, seems too lenient. The government should also waste
no time in
regulating small incinerators that are now exempt from law.

Besides, there is no denying that people living near incinerators may be
taking in more than 4 picograms of dioxin per kilogram of body weight.
This makes even
more important to establish an environment standard.

The government intends to revise and upgrade the "guideline" on air
pollution into an environment "standard" based on law. The new guideline
has set the limit of
dioxin emissions from incinerators on the assumption that ingesting 5
picograms of dioxin per kilogram of body weight--half the tolerable
daily intake in effect
now--will not harm people's health.

The Environment Agency probably set this guideline at 5 picograms apart
from the existing tolerable daily intake number because the agency
thought that a
10-picogram figure would discourage efforts to reduce dioxin emissions.

Therefore, there is no reason why the agency should stick to the
4-picogram figure in setting up a new environment standard.

It would be advisable to create an environment standard target about air
and water on the basis of the under-1-picogram figure used by the World
Health
Organization.

The latest conclusion of the advisory panels also refers to the
permissible dioxin intake by babies who are being breast-fed. The
panels' figure is incomparably larger
than that for adults. It appears that the large number was taken for
only a short period because it is applied when people are infants.

To ease the worries that mothers feel about their infants, detailed
advice should be given. Mothers cannot dispel their fears merely by
being told that the density of
dioxin in mothers' milk has continued to decrease.

As studies into dioxin advance, new dangers surface. Unless pre-emptive
measures are taken, there may be more trouble in the future. (Asahi
Shimbun, June 23)