Yoshitoku Yoshida
Environmental
Health and Safety Division
The
Ministry of the Environment, Japan
In Article 16 of
Stockholm Convention for the global elimination of Persistent Organic
Pollutants (POPs), it is written that "comparable monitoring data"
reported by the Parties will be used for the "effectiveness evaluation of
the Convention". A
detailed evaluation scheme will be decided by the Conference of the Parties,
but various technical aspects of this POPs monitoring were discussed by the
international experts at UNEP Chemical's workshop on the development of Global
POPs Monitoring held in Geneva in March 2003, and the guidance documents for
the monitoring are now being prepared based on the results of the
workshop.
The Ministry of the
Environment (MoE), Japan, has been conducting
environmental monitoring of various pollutants including major POPs in Japan for
more than two decades, and reported the results every year in a report
“Chemicals in the Environment” (or KUROHON, meaning “black book” in
Japanese). Originally a
conventional GC/ECD method had been employed for the analysis of organochlorine chemicals (OCs) in
biological samples. Then a GC/MS
(low resolution) was introduced for OCs analysis in
sediments and water, and GC/high resolution(HR)-MS
method was introduced for dioxins analysis from around 1990. Due to general decline of POPs levels in
the environment, the number of ND (not detected = less than detection limits)
data had been increasing in recent years, and consequently it became difficult
to extract temporal trends from the monitoring data. In 2002, MoE
decided to reorganize the environmental monitoring framework in order to
respond to the request of POPs convention, and re-started POPs monitoring by
using more sensitive GC/HR-MS method for the analysis of nine POPs chemicals
(dioxins and furans have already been monitored by the method; toxaphene is analyzed by GC/negative ionization-MS). The primary purpose of this
reorganization is to reveal present POPs levels in Japan as a basis to judge
the effectiveness of the measures/countermeasures taken by the Government for
POPs convention. Detailed
explanation of the new monitoring methods and the results of the first year
(FY2002) will be presented separately.
Briefly the results of
the previous POPs monitoring for more than two decades are summarized as
follows;
1) Dioxin
levels (including furans and co-PCBs) in the air decreased to one fifth in
average from 1997 to 2001. The
decrease coincides well with the decrease of estimated national emission
inventory (one fourth from 1997 to 2001).
2) The dioxin
levels in the air tend to be higher in densely populated areas than rural /
remote areas.
3) The dioxin
levels in water decreased to half from 1998 to 2001, while the estimated
emission inventory decreased to one third during the period.
4) The dioxin
levels in sediments and soils did not show clear decreasing trends during the
period between 1998 and 2001.
5) PCB levels
in fishes in Tokyo Bay and Osaka Bay tended to be higher than fishes in other
places. They showed no clear
temporal trends during a quarter of century.
6) HCB, Aldrin and Endrin were not
detected in many of the biological samples in recent years. Dieldrin was
detected only in limited numbers of samples, including mussels and sediments.
7) DDTs were detected in many biological
samples. The dominant compound, p,p’-DDE, showed
general decreasing trends in fishes and bivalves in Western Part of Japan while
the clear temporal trends could not be observed in those in Eastern Japan.
8) Chlordane
levels were relatively higher in fishes caught in Tokyo and Osaka Bays than in
other coastal region. They showed general
decreasing trends in recent years.
Their levels in sediments also tend to be higher in coastal environment
in densely populated areas.
9) Heptachlor
was detected in only limited number of samples while mirex
and toxaphene were not detected.
MoE also
conducted efforts to support implementation of POPs convention and
establishment of regional framework for the convention. MoE hosted the
1st and the 2nd Workshops on POPs monitoring in East
Asian countries in December 2002 and 2003, respectively. The workshop was intended as a forum for
the discussion and information exchange on POPs monitoring among countries in
the region, and the proceedings of the 1st workshop was distributed
at the UNEP Chemicals workshop in Geneva, and also at INC-7 in Geneva. As a consequence of the two workshops, MoE is planning to support to establish an expert working
group of scientists designated by the East Asian Countries, and also to support
to conduct trial (air) environmental monitoring in background sites including
training for the analysis from this year.
Regulation of POPs
Chemicals in Japan
|
Name |
Banned
as
Banned as Industrial
Chemicals
Pesticides |
|
DDT Aldrin Dieldrin Endrin Chlordane* Heptachlor** Mirex Toxaphene PCB HCB |
1981 1971 1981 1975 1981 1975 1981 1975 1986 1968 1986
1975 2002 *** 2002 *** 1974 1979 *** |
*: used mainly for termiticides (other than agricultural purposes); between
1979~1986.
**: Heptachlor was also included in technical
chlordane as impurity (~10 %).
***: never registered as agrochemicals in Japan