NIMD Forum 2012
Current topics of mercury impact
to human and environment

26 January 2012
Conference Hall, Minamata Disease Archives
National Institute for Minamata Disease
Minamata City, Kumamoto, Japan

NIMD Forum 2012

Minamata City, 26 January 2012

Programme
Opening Session
9:00

-

9:10

Pages
Opening Remarks NIMD
Director-General Juichi Abe

9:10

-

9:40

Darko Viler

Idrija Municipal Museum, Republic of Slovenia

Introduction of Idrija City and municipal Museum
9:40

-

10:10

Tetsuhiro Yoshimoto

Minamata City

Steps Taken by the Minamata City, “Environmental Model City”
10:10

-

10:30

Milena Horvat
10:30

-

11:00

NIMD
Jožef Stefan Institute, Republic of Slovenia

Tatjana Dizdarevič Idrija Mercury Mine, Ltd., Republic of Slovenia“Closure of the Mercury Mine and the Quality of Life in Idrija”

11:00

-

11:30

8

Coffee Break
Chair: Akito Matsuyama

Session Ⅰ

3

Milena Horvat

14Jožef Stefan Institute, Republic of Slovenia“Mercury fate and transport in the wider Idrija Region and the Gulf of Trieste; fromenvironmental measurements to modeling tools.”
11:30

-

12:00

Akito Matsuyama

21

NIMD

“Mercury concentration in fish muscle (Pargus major) based on current seawater
characteristics of Minamata Bay.”
12:00

-

13:00

Lunch
Chair: Keisuke Mori NIMD

Session Ⅱ

Nives Ogrinc
13:00

-

28

13:30

Nives OgrincJožef Stefan Institute, Republic of SloveniaJožef Stefan Institute, Republic of Slovenia“Mercury in contaminated coastal sediments: novel approaches in source
appointment.”
13:30

-

14:00

Keisuke Mori

31
NIMD

“Mercury pollution by many small-scale gold ore smelters in Talawaan River, North
Sulawesi, Indonesia.”
14:00

-

14:30

Janja Snoj Tratnik

36Jožef Stefan Institute, Republic of Slovenia“Biomarkers of low level mercury exposure: exposure, impact and genetic
susceptibility.”
14:30

-

15:00

41

Choong Hee Park National Institute of Environmental Research, Republic of Korea"National Environmental Health Survey - Mercury Concentration in Blood andUrine -"

15:00

-

15:20

46

Coffee BreakI

NIMD Forum 2012

Minamata City, 26 January 2012
Chair:Mineshi Sakamoto

Session Ⅲ

Milena Horvat
15:20

-

15:50

Mineshi Sakamoto

NIMDJožef Stefan Institute, Republic of Slovenia

NIMD“Placental transfer of heavy metals and the changes in their body burden in infants
during early-breastfeeding period.”
15:50

-

16:20

50

Young-Seoub Hong Dong-A University, School of Medicine, Republic of Korea“The blood mercury concentration in a coastal area and four cases ofneuropsychological abnormal findings in children with high blood methyl-mercury
concentration in Korea”

16:20

-

16:50

53

Pablo Higueras Universidad de Castilla-La Mancha, Spain“Health effects of mercury in Almadén, the world's largest mercury mining district.”

16:50

-

17:00

Closing Remarks
Director-General Juichi Abe

II57

NIMD Forum 2012

Minamata City, 26 January 2012

Introduction of Idrija town and Municipal Museum
Darko Viler
The Idrija Municipal Museum
Idrija is a small town in Slovenia and the site of the second largest mercury mine in theworld.
It lies in a valley 300 meters above sea level, on a tectonic fault running from northern Italyto the Adriatic, which is also the border between the pre-alpine and Karst regions. The ore deposit
originated due to geological activity at the fault. The town developed at the confluence of the Idrijca
and Nikova rivers, amid dense forests. In the past it was precisely wood and water that contributed
significantly to successful extraction of mercury. According to legend, in 1490 a bucket makerdiscovered an unusually heavy, glittering substance in a stream. Identified as mercury, it resulted inquick arrival of prospectors from Italian, German and Czech lands. Idrija is the seat of amunicipality with population 12,000, half of them living in Idrija itself. Idrija lies an hour's drivefrom Ljubljana, the capital of Slovenija, 450 kilometers from Vienna, historically the capital of the
Habsburg Monarchy, 200 kilometers from Venice and 100 kilometers from Trieste, the two
historically important ports for mercury exports.
The Idrija Municipal Museum is a public institution with administrative seat at
Gewerkenegg Castle in Idrija, which was built just decades after mine opening. The Museum has
two units, the Idrija Department and the Cerkno Department. The former organizes exhibitions in
the renovated Castle complex, and houses the permanent exhibition entitled »Five Centuries of the
Mercury Mine and the Town of Idrija«, which the Luigi Micheletti Foundation from the European
Museum Forum declared the Best European Museum of Industrial and Technical Heritage in 1997.
The Idrija Department is also responsible for the many technical and cultural monuments, including
the Idrija Kamšt (a large water-driven pump), a set of restored large mine machinery in the Francis
Shaft, a miner's house, and the WWII Slovenia Partisan Printing Shop on the Vojsko plateau near
Idrija. The Cerkno Department offers two new permanent exhibitions: »The Cerkno Region
Through the Centuries« and »Pust is to Blame! – The Story of the Laufarji from Cerkno«,
displaying local spring festival traditions. The Department also invites visitors to the homestead ofwriter France Bevk in Zakojca near Cerkno, and devotes special care and attention to a remarkable
WWII monument – the Franja Partisan Hospital in Dolenji Novaki near Cerkno.

3

NIMD Forum 2012

Minamata City, 26 January 2012

イドリヤ市とイドリヤ地方博物館の紹介
イドリヤはスロベニアの小さな町であり、世界で 2 番目の大きな水銀鉱山を有している。
イドリヤはイタリア北部からアドリア海に走っている断層の上の海抜 300 メートルの谷に位置し、また前アルプス山脈とカルスト地域の境を接するところでもある。地質学活動により断層部に鉱石が堆積した。町はイドリヤ川と Nikova 川の合流地点、深い森の中に発展した。昔はこの森と水が水銀の輸出に大いに役立った。
イドリヤ歴史博物館は Gewerkenegg 城内にある公共の施設で、鉱山が開かれて数十年後に建てられたものだ。博物館はイドリヤ部と、Cerkno 部という二つのユニットに分かれている。町がこの城の修復、展示物の管理にあたっており、「5 世紀にわたる水銀鉱とイドリヤの街」と題した常設展示品を収蔵している。
また Cerkno 部には “世紀を超えて、Cerkno 地方”や、“Cerkno 出身の Laufarji の話”等の新たな常設展示が加わり、また春節祭の伝統等も紹介している。

4

NIMD Forum 2012

Minamata City, 26 January 2012

5

NIMD Forum 2012

Minamata City, 26 January 2012

6

NIMD Forum 2012

Minamata City, 26 January 2012

7

NIMD Forum 2012

Minamata City, 26 January 2012

Steps Taken by the Minamata City, “Environmental Model City”
Tetsuhiro Yoshimoto
Minamata City
Minamata City is located in the southern part of Kumamoto Prefecture. In 1900’s it is asmall-scale city with abundant blessings from sea, mountains, rivers and mild climate and its
population is about 27,000 and the area is 162 km². It was a mere small farming and fishing village
with the population of about 12,000 in 1900’s. However, after the establishment of the Minamata
Factory of Japan Nitrogenous Fertilizer Company (the forerunner of Chisso Corporation) in 1908,the city developed as an industrial city along with rapid increase of the population.
The New Japan Nitrogenous Fertilizer Company resumed production of vinyl choloride in1949 and around 1950’s serious health damage appeared on human in fishing villages. Since thedirector of the hospital attached to the New Japan Nitrogenous Fertilizer Company reported theoccurrence of the patients to the Minamata Health Center on May 1, 1956, this day has become theday of official confirmation of Minamata disease.
At that time the cause of this disease could not clarified at all. Because of themisunderstandings of this sickness as contagious disease, the families with the patients received
discrimination and prejudice and many people died painful deaths.
In 1956, the population of the city exceeded 50,000 and the city had gotten flourished more
and more while the outbreak of the disease continued mainly in fishing villages.
Due to the complex regional factor that sufferers and wrong doers were living in the same
town, mutual distrust grew gradually among the residents. That led the local community to collapse
and have a long confused period.
Some years later the cause of the Minamata disease became clear and in 1977 the Minamata
Bay Pollution Prevention Project in which dredging of the sedimentary sludge containing mercury
in and out of the Minamata Bay and reclamation was initiated in order to prevent diffusion of thedamage. In 1990 the project was completed and the reclaimed area has become an eco-park.
And in January, 1993, the Minamata Disease Municipal Museum was opened to collect andkeep materials and to disseminate the information in order to make use of the lesson of Minamata
Disease in the future. Up to these days approximately 750,000 people have visited from home andabroad. Particularly all the fifth graders of Kumamoto Prefecture visit every year as a part of theirenvironmental study.

8

NIMD Forum 2012

Minamata City, 26 January 2012

「環境モデル都市」みなまたのあゆみ
水俣市は、熊本県の南に位置し、人口約 27,000 人、面積約 162 平方キロメートルで、海・山・川と自然が豊かで温暖な気候に恵まれた小規模都市です。1900 年頃は、人口 12,000 人余りの小さな農漁村に過ぎませんでしたが、1908 年にチッソ株式会社の前身である日本窒素肥料株式会社水俣工場が設立されてからは人口も急速に増加し、工業都市として発展の途を歩むこととなります。
1949 年に新日本窒素肥料株式会社が塩化ビニールの生産を再開、1950 年代頃から漁村において人に重大な健康被害が見られるようになり、1956 年 5 月 1 日に新日本窒素付属病院院長が水俣保健所へ患者発生の報告を行ったことから、この日が水俣病公式確認の日となっています。
当時は、病気の原因が全く分からず、患者が発生した家庭は伝染病など誤解され差別や偏見を受けながら、多くの人が苦しみのなか亡くなっていきました。
1956 年に本市の人口が５万人を超え市勢は拡大の一途をたどる傍ら、漁村地域を中心に患者の多発が続きました。
ひとつのまちに被害者と加害者が混在するという複雑な地域事情から、次第に住民間に相互不信が起こることとなり、そのことがそれまで築き上げてきた地域コミュニティを崩壊へと向かわせ、長く混迷の時代が続くこととなりました。
やがて水俣病の原因も判明し、被害の拡散を防止するため水俣湾内外に堆積した水銀ヘドロの浚渫・埋め立てを行う水俣湾等公害防止事業が 1977 年に着手され、1990 年に工事が完了、現在エコパー
クとして親しまれています。
また、1993 年 1 月水俣病の教訓を後世に生かすため、資料を収集・保存し、情報を発信することを目的として、水俣市立水俣病資料館が開館しました。現在まで、国内外から 75 万人の方が訪れています。特に小学校の環境学習の一環として、熊本県内全校の小学 5 年生は毎年来館しています。
本市は、これまでの長い混迷と苦しみを教訓に、二度と人の健康や環境に悪影響を及ぼすことがな
いよう、1992 年に全国に先駆け「環境モデル都市づくり」宣言を行い、水俣再生の目標としました。
家庭などから出るゴミの高度分別への取り組みを初め、学校などにおける環境ＩＳＯの取り組み、食など安全にこだわったものづくりを実践する環境マイスターの認定、国によるエコタウンの承認、みなまた環境大学事業の実施など、市民協働の取り組みを行い、住民同士の絆を取り戻す「もやい直し」
へと進んできました。
このような実践行動が高く評価され、2001 年から 10 年間実施された NGO による「日本の環境首都コンテスト」において 2011 年 3 月に「日本の環境首都」の称号を獲得しました。
本市は、これからも持続可能な地域社会のさらなる構築を目指すとともに、「真の豊かさ」を感じることができ、多くの人が交流する活力あるまちを、市民協働で築いていきます。

9

NIMD Forum 2012

Minamata City, 26 January 2012

10

NIMD Forum 2012

Minamata City, 26 January 2012

11

NIMD Forum 2012

Minamata City, 26 January 2012

12

NIMD Forum 2012

Minamata City, 26 January 2012

13

NIMD Forum 2012

Minamata City, 26 January 2012

Closure of the Mercury Mine and the Quality of Life in Idrija
Tatjana Dizdarevič1, Urška Repinc2
1: Idrija Mercury Mine, Ltd. – in liquidation

2: Municipality of Idrija; Slovenia
The town of Idrija is known worldwide mostly for its mercury mine, one of the oldest minesin Europe. It has been estimated that from 1490 till 1995 over 12 million tons of mercury ore wereexcavated and a total of 153,309 tons of commercial mercury (Hg) were extracted, which represents
over 13% of the entire world Hg production to date. All activities in the Idrija Mercury Mine
Company relating to the shutdown of the mine were completed by the end of the year 2009.
In view of man’s growing ecological awareness in the 70’s, when Hg production reached its
final peak, first systematic measurements of total mercury in water, soil, air, plants, animals andhumans were introduced. Mining and reprocessing of ore has severely enhanced the mobilisation of
Hg - it has been estimated that during the mine operation about 44,616 tons of Hg have beenreleased to the environment uncontrolled. Unfortunate outcome of the mining activities has been theconstant exposure of the inhabitants of Idrija and miners to Hg. Considerable decrease of Hg
content in air in Idrija was observed in the last decades after the processing of mercury ore in thesmelting plant was discontinued. The concentrations of Hg in air were reduced from about 2,000
ng/m3 in 1970’s to about 10 ng/m3. Airborne Hg caused elevated Hg levels in surficial soil layers.
On specific locations naturally increased levels of mercury are found in soil where the ore deposit
reaches the surface in the immediate area of the town (Pront area), or due to many abandoned
improvised smelting/tailing sites from the earlier periods of Hg production. Despite drastic
reduction and final ceasing of mining and smelting activities in Idrija in the 90’s, the mercury
concentration in soils and vegetation remain high. Though Hg levels in vegetation are several ordersof magnitude lower than those in soils, the results show high persistence of Hg, despite drasticallydiminished airborne Hg emissions. Concentrations of Hg in surface waters upstream are below 10
ng/L and downstream of the mining district increase to about 200 ng/L, and remain elevated until
the confluence with the Soča River. Significant decrease of Hg concentrations in surface water with
the increasing distance from the town of Idrija is observed today. The fact is that Hg concentrations
in river sediments are still relatively high and there are no signs of the expected decrease.
Concentrations of Hg in mine waste water, which is periodically released to Idrijca River, arewithin the permitted values set by Slovenian legislation. The tailings and contaminated soils in the

14

NIMD Forum 2012

Minamata City, 26 January 2012

Idrija region are continuously eroded and serve as a continuous source for the river and the flood
plains. Therefore Idrija area continues to supply Hg into the Idrijca River and Soča river systems,
which empties into the Gulf of Trieste some hundred km downstream. At the current level of
exposure to Hg in the town of Idrija, no directly perceivable toxic effects are expected. Nutritional
habits of inhabitants have changed in the past decades; therefore the intake of Hg through inhalationis considered the most significant. The latest study on mercury exposure revealed that children
living in the area of the former mercury mine are not under any significantly elevated risk ofmercury exposure.
Although Hg is present in Idrija region mostly in inorganic forms, numerous researchstudies were performed to address Hg, transport and transformation processes of different Hg
species in Idrija region. The results have served as a basis in preparing long term rehabilitation
measures for reducing the effects of the past mining activities. On the basis of the provisions of the
EU Strategy for Mercury (2005) as well as the applicable laws and implementing regulations of the
Republic of Slovenia (1999-2004) stipulating the final rehabilitation of the environment andelimination of the consequences of mining works, the Mining project of monitoring in the period
after the termination of mining activities in the Idrija Mercury Mine was prepared. Also
Municipality of Idrija has become aware of the importance to address environmental issues in order
to continuously improve the quality of life of its inhabitants. The strategic goals of the Idrija
Municipal Environmental Protection Program prepared in 2009 include the setup of an effective
environmental management system (ISO 14001), reduction of environmental pollution, regulationof public utility infrastructure, waste management, sustainable use of energy, protection of natural
resources and biotic diversity, as well as awareness raising and information transfer.
The decision that Slovenia can also contribute to the full implementation of the EU Strategy
concerning mercury led to the establishment of the Information and Research Centre for Mercury(IRC Hg) in Idrija in June 2008. The opening of this Centre has brought new dimensions to theexisting activities of the Idrija Mercury Mine. Unfortunately IRC Hg could not reach its potential
due to the liquidation process of the Idrija Mercury Mine, which started in 2010. The Slovenian
Government is currently working on establishment of a new public institute named Idrija Mercury
Heritage Management Centre, whose operation will also be harmonised with the management plan
according to the application for inscription on UNESCO's World Heritage List. The international
project "Heritage of Mercury. Almadén and Idrija" nominated by Slovenia and Spain for inscription
on UNESCO's World Heritage List, is by all means one way of directing and planning activities in
the future. Emphasis is laid on the conservation, development and presentation of heritage of
exceptional universal value to contribute to a broader awareness of its significance and respect, as
15

NIMD Forum 2012

Minamata City, 26 January 2012

well as to the sustainable development of the region and the local community. In addition totechnical and cultural attractions, we are also aware of the natural features in the environment of
Idrija. With its exceptional geological heritage, botanical diversity, unique forests and rich mining
heritage, Idrija holds an important place in the European environment. The emerging Geopark
Idrija, which represents a form of informal protection, interpretation, promotion and marketing of
natural heritage in a geographical area, connects natural and cultural heritage in a unique andoriginal way.
For almost 500 years the Idrija Mercury mine was the only driving force for development in
Idrija region. The crisis in the mercury market in the 1970's and consequently the stagnation of the
Idrija Mercury Mine favoured and led to the development of more environmentally friendly
technologies and industry, that changed the appearance of the town in many aspects. Rich scientific,
technical and cultural heritage that gave unique and recognizable shape to Idrija town during half acentury of mercury mining, is a legacy of immeasurable value, therefore we shall have to find ways
to preserve it for the generations to come.

イドリヤの水銀鉱山の閉鎖と生活の質
イドリヤの町はヨーロッパで一番古い水銀鉱山として世界的に知られている。1490 年から 1995 年まで 1,200 万トン以上の水銀鉱石が掘り出され、合計で 153,309 トンの商業水銀が掘り出された。これは現在までで全世界の水銀生産の 13％以上になる。鉱山閉鎖に関連した活動は 2009 年末に完了した。
大気中の水銀の大幅な減少は、精錬工場での水銀鉱石の加工が止まった後の過去 10 年に観測された。
大気中の水銀濃度は約 2,000 ng/m3 から 1970 年代には約 10 ng/m3 にまで減少した。大気中の水銀が、地層表面の水銀レベルの増加を引き起こした。90 年代におけるイドリヤの採鉱や溶錬活動の徹底した現象にもかかわらず、土壌と植生中の水銀濃度は依然として高いままである。川の堆積物中の水銀濃度はいまだに高く、イドリヤ地域の汚染された土壌は継続的に浸食され川と洪水が起きる平原へ連続的な水銀放出の源となっている。
また、イドリヤ市は住民の生活の質を継続的に向上するために環境問題の重要性を指摘しており、2009 年に設定されたイドリヤ市環境保護プログラムの戦略目標には効果的な環境管理システム、環境
汚染物質の減少、電気、ガスなどのインフラ、廃棄物管理、持続的なエネルギー利用、天然資源の保
護、生物の多様性の設定、さらには意識の向上と情報伝達などが含まれている。スロベニア政府は現
在イドリヤ水銀遺産マネジメントセンターという名称の新しい公共機関を設立中である。この機関の運営は UNESCO の世界遺産リスト登録への申請に向けての管理計画と協調するもので、スロベニアとスペインによって UNESCO の世界遺産リストに推薦された国際的なプロジェクト、“水銀の遺産 ア
ルマデンとイドリヤ”は、未来を目指した行動の計画である。
約 500 年もの間イドリヤ水銀鉱山は、イドリヤ地方で唯一の開発の原動力であった。1970 年代の水銀市場の危機とその結果としてイドリヤ水銀鉱山の不振は、より環境にやさしいテクノロジーや産業に尽力した。その結果町の様相は様々な観点で変貌した。水銀採鉱の半世紀の間イドリヤの町に独特で明確な形を与えた豊かな科学的、技術的、文化的な遺産は計り知れない価値の遺産であり、我々は来たるべき世代に対し保存する道を見出すべきである。

16

NIMD Forum 2012

Minamata City, 26 January 2012

17

NIMD Forum 2012

Minamata City, 26 January 2012

18

NIMD Forum 2012

Minamata City, 26 January 2012

19

NIMD Forum 2012

Minamata City, 26 January 2012

20

NIMD Forum 2012

Minamata City, 26 January 2012

Mercury fate and transport in the wider Idrija Region and the Gulf of Trieste;from environmental measurements to modelling tools
Milena Horvat1, Dušan Žagar2, Rudolf Rajar2, Matjaž Četina2,
David Kocman1, Jože Kotnik1, Nives Ogrinc1
1: Department of Environmental Sciences, Jožef Stefan Institute, Ljubljana

2: Faculty of Civil Engineering and Geodesy, University of Ljubljana; Slovenia
Mercury (Hg) mining activities in Idrija, Slovenia, have resulted in significant

environmental contamination. Hg contaminated soils, Hg-laden material and tailings continue tosupply Hg to the local river system and to the Gulf of Trieste in N Adriatic, some 100 km
downstream from the mercury mine. Due to the abundant precipitation, steep slopes and highly
erodible underlying lithology, this region is especially prone to erosion. In the last 10 years
numerous measurement campaigns were implemented and used for the validation of modeling tools
to better describe and simulate the fate and transport of mercury in the catchment area, estuarine
and the costal environment of the Gulf of Trieste. Such an approach has been demonstrated to be an
efficient tool for the resource management planning, including remediation in the riverine andcoastal environment.
The presentation will provide examples of recent developments in the use of Erosion
Potential Method (EPM) in a Geographic Information System (GIS) environment (Kocman andHorvat, 2009, 2011) which was used to estimate mercury delivery to the receiving water bodyassociated with the contaminated soil loss from the Idrijca River catchment draining the area of themine. Surface geology and soils, topographic features, climate, and land use were taken into
consideration and validated against mercury measurements in soils and suspended solids delivered
to the riverine system. Based on the spatial distribution of mercury in catchments soils the averageannual Hg load to the Idrijca River system was predicted at 933 kg. Due to the high variability inspatial distribution of mercury in soil areal loads vary significantly and are the highest in the areasurrounding the mine (5 – 20 mg Hg m-2 yr-1). In addition, based on the site-specific empiricalcorrelations between the measured Hg emission fluxes and the parameters controlling the emission,a mercury emission model was developed within GIS to simulate non-point source mercury
emissions at the catchment scale. The most contaminated areas surrounding the mine that represent
less than 5 % of the catchment contributes 25 % of total annual mercury load to the Idrijca River

21

NIMD Forum 2012

Minamata City, 26 January 2012

system. In this way, spatial distribution and significance of most polluted sites that need to beproperly managed were assessed.
In the marine environment, tha fate and transport model PCFLOW3D previously developed(Rajar et al., 2004, 2006; Žagar et al. 2006, 2007) has been improved in order to (1) forecast water
circulation in the areas under study in adequate spatial and temporal resolution, (2) simulatetransport and fate of pollutants on the basis of measured and modelled input parameters and (3)perform nearly real-time short-term simulations. Previous studies (Žagar, 1999, Rajar et al., 2000)
showed high impact of wind induced waves and currents on bottom sediment resuspension andtransport, particularly in the northern, shallow part of the Gulf. Therefore, the PCFLOW3D model
has recently been upgraded with a module for prediction of wave parameters and wave-induced
bottom shear stress from wind speed and direction measurements at the buoy positioned near thecoastline. The module is based on an artificial neural network algorithm. The improved modelallows for simulation of more environmental parameters and to account for the impact of several
new variables on mercury transformations in much better horizontal and vertical scale (approx.
150x150 m and the layer thickness is 1 m). Such a model allows for an effective use in theadvanced integrated monitoring system in which the measurement data from buoys and robots aretransferred via web-interfaces from the AmI database to PCFLOW3D and the modelling results arethen fed back to the database. GIS models are applied to simulate conditions in the backgroundareas and to determine riverine inputs. Using all the described improvements and the significantly
larger quantity and better quality of input data, it is expected to increase the accuracy of mercury
transport and transformations simulated with the PCFLOW3D model.

Acknowledgement
The EU FP7/2007-2013 (grant agreement n° 212790 – HYDRONET) and the ARRS of the R
Slovenia is acknowledged for financial support.
References:
Kocman D, Horvat M. 2009. A laboratory based experimental study of mercury emission from contaminated soils in
the River Idrijca catchment. Atmos. Chem. Phys. Discuss. 9/6, 25159-25185.
Kocman D, Horvat M. 2011. Non-point source mercury emission from the Idrija Hg-mine region: GIS mercury
emission model. J. Environ. Manag, 92/8, 2038-2046.
Rajar R, Žagar D, Širca A, Horvat M. 2000. Three-dimensional modelling of mercury cycling in the Gulf of Trieste.
Sci. total environ. 260, 109-123.

22

NIMD Forum 2012

Minamata City, 26 January 2012

Rajar R., Žagar D., Četina M., Akagi H., Yano S., Tomiyasu T., Horvat M. 2004. Application of three-dimensional
mercury cycling model to coastal seas. Ecol. model., 171/1/2, 139-155.
Rajar R, Četina M, Horva M, Žagar D. 2007. Mass balance of mercury in the Mediterranean sea. Mar. Chem., 107/1,
89-102.
Žagar, D. (1999) Development and application of a three-dimensional model to simulate mercury transport andtransformation process in the marine environment, Acta Hydrotechnica, 17, 27. 68.
Žagar, D.; Knap, A.; Warwick, J.J.; Rajar, R.; Horvat, M.; Četina, M.2006. Modelling of mercury transport andtransformation processes in the Idrijca and Soča river system. Sci. Tot. Environ. 368: 149– 163.
Žagar D., Petkovšek G., Rajar R., Sirnik N., Horvat M., Voudouri A., Kallos, G. B., Četina M.. 2007. Modelling of
mercury transport and transformation in the water compartment of the Mediterranean Sea. Mar. Chem.., 107/1, 64-88.

広域イドリヤ地方とトリエステ湾での水銀の命運と輸送; 環境測定からモデル化手法までスロベニアのイドリヤにおける水銀鉱山活動は、深刻な環境汚染を引き起こした。水銀は、土壌を汚染し、水銀を含む物質及びテーリング（尾鉱）は水銀鉱山から数 100 ㎞にわたって、地域の河川系、さらには北アドリア海のトリエステ湾に水銀を供給し続けている。豊富な雨量、険しい勾配、受食性の高い岩質のせいで、この地域は特に浸食されやすい。過去１０年間に膨大な計測の運動が履行され、最終結果の予測と水銀が流域、河口、トリエステ湾の沿岸の環境にどのように運ばれるかをよりよく説明するための検証に使用された。これらの取り組みは河川と沿岸環境の修復を含む資源の管理計画
にとり効率的な道具になることを示してきた。
今回の発表では、地理情報システム（GIS）環境におけるエロージョン・ポテンシャル法(EPM)を用い た 最 近 の 研 究 の 例 を 示 す (Kocman and Horvat, 2009, 2011) 。 海 洋 環 境 で は 動 態 と 輸 送 モ デ ル
PCFLOW3D が既に開発されていて(Rajar et al., 2004, 2006; Žagar et al. 2006, 2007)、さらに改良され、以下を可能にしている。（1）適正な空間的かつ時間分解能における研究が行われている地域の水の循環の予測（2）測定値と入力されたモデル値を基とした運送と命運のシミュレーション（3）現実に近い
短時間のシミュレーションの実行。先の研究(Žagar, 1999, Rajar et al., 2000)では、沈殿土砂上の再懸濁と輸送における風に引き起こされた波と流れによる影響の大きさを示した。また、更なる改良を加え、膨大な量とより良い質の入力データのを用いて、PCFLOW3D モデルでシミュレートされた水銀の輸送と変換の正確さが増加することが予測される。

23

NIMD Forum 2012

Minamata City, 26 January 2012

24

NIMD Forum 2012

Minamata City, 26 January 2012

25

NIMD Forum 2012

Minamata City, 26 January 2012

26

NIMD Forum 2012

Minamata City, 26 January 2012

27

NIMD Forum 2012

Minamata City, 26 January 2012

Mercury concentration in fish muscle (Pargus major) based on current seawater
characteristics of Minamata Bay
Akito Matsuyama
Department of Epidemiology, National Institute for Minamata Disease
In Minamata Bay, the dredging project involving sediment with a mercury concentration of
more than 25 ppm was implemented from 1977 until 1990. Then, currently, Sebastiscus marmoratus,
and Pseudolabrus japonicus are specified as a monitoring fish for mercury pollution in Minamata
Bay. Recently, average values of total mercury concentration in fish muscle for 3 years (2008-2010)of these fishes were 0.36 ppm and 0.20ppm, respectively. On the other hand, the average values of
total mercury concentrations of these fishes in Japan are 0.12 ppm and 0.04 ppm respectively. FDA(2001, 2004) and Health Canada (2008) suggested that a part of mercury accumulated in fish isderived from seawater. Therefore, to evaluate absorption and accumulation of mercury in fish, thefish cage experiment using young fish (red sea bream) and a special fish food that do not include
mercury was carried out for 2 years continuously in Minamata Bay and Nagashima (control). As aresult, there was no difference on mercury accumulation in fish muscle (red sea bream) between
Minamata Bay and Nagashima. Therefore, generally, in case of red sea bream, it seems to be mostmercury that was accumulated in fish muscle is not from seawater, then it was reconfirmed thatmost mercury that was accumulated in fish muscle is from diet in the sea based on our results.

水俣湾の現在の海水特徴に基づく魚（マダイ）筋肉中の水銀濃度

水俣湾では 1977 年から 1990 年にかけて水銀濃度 25ppm を超える堆積物を埋め立てるため浚渫工事が行われた。現在カサゴとササノハベラが水俣湾の水銀汚染観察対象魚とされている。
この 3 年間（2008～2010）、この魚の筋肉における水銀濃度平均値はそれぞれ 0.36ppm、0.20ppm であった。一方、日本におけるこの魚の一般的な水銀濃度平均値は各々0.12ppm、0.04ppm である。FDAと Health Canada では魚の水銀蓄積の一部は海水によるものとしている。
よって、魚の水銀蓄積とその吸収を評価するため真鯛の稚魚と水銀を含まない特定の餌を使用し、魚ケージによる実験を 2 年間連続で水俣湾と長島（対象地）の海水域で行った。
その結果、魚（真鯛）の筋肉おける水銀蓄積には水俣湾と長島間での違いは認められなかった。よって真鯛に関しては、魚の筋肉に蓄積される水銀のほとんどは海水によるものではなく、そのほとん
どは海から採取される食物によることが再確認された。

28

NIMD Forum 2012

Minamata City, 26 January 2012

29

NIMD Forum 2012

Minamata City, 26 January 2012

30

NIMD Forum 2012

Minamata City, 26 January 2012

Mercury in contaminated coastal sediments: novel approaches in source
appointment
Nives Ogrinc1, Milena Horvat1, Jože Kotnik1, Jadran Faganeli2,Mark Hines3, Holger Hintelmann41: Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia

2: Marine Biological Station, National Institute of Biology, Fornače 41, 6330 Piran, Slovenia

3: Department of Biological Sciences, University of Massachusetts Lowell, One University Ave, Lowell,MA 01854, USA

4: Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Canada

Contamination with mercury (Hg) on coastal sediments is initially suspected based on
historical land use such as mining or industrial activity. Hg mining results in a legacy ofcontamination that can occur on large distances from the source. The Gulf of Trieste represents an
ideal case study where large quantities of Hg have been released into the environment of Hg mines
due to inefficient mining procedures and incomplete extraction of Hg in Idrija mining district.
Several research studies were performed in order to track the transport and transformation pathwaysof Hg in this Hg contaminated coastal region (Horvat et al., 1999, Covelli et al., 2001). It was foundthat Hg was methylated and demethylated everywhere in the gulf sediments (Hines et al., 2000).
The freshwater to marine gradient is dynamic, exhibiting seasonally and horizontally variable rates
of sulfate reduction and Hg transformation. Hg mobilization and methylation were driven by S
cycling, but coastal demethylation may significantly attenuate the accumulation of methylmercury(MeHg). In general concentrations of MeHg correlates well with total Hg in sediments in noncontaminated environments (Ogrinc et al., 2007), however this is not always the case in polluted
coastal environments, indicating that environmental factors play an important role in mercury fate
and transport. As expected, the ratio between MeHg and total Hg in sediments is low with anaverage value of 0.32. Novel instrumental techniques based on stable isotope fractionation werealso applied in order to trace the sources of Hg in surficial sediments of the gulf (Foucher et al.,2009). It was found that the Hg isotopic composition of river sediment was similar to that of
cinnabar ore from upstream. We concluded that sediments throughout the watershed of Soča/Isonzo
River to the Gulf of Trieste were dominated by Hg exported from the headwaters near the Idrija Hgmine progressively decreasing from > 90% in the northern part to < 45% in the southern Gulf.
References:

31

NIMD Forum 2012

Minamata City, 26 January 2012

Covelli, Stefano, Faganeli, Jadran, Horvat, Milena, Brambati, Antonio. 2001. Mercury contamination of coastal
sediments as the result of long-term cinnabar mining activity (Gulf of Trieste, northern Adriatic sea). Appl. geochem.,
16/4, 541-558.
Foucher Delphine, Ogrinc, Nives, Hintelmann Holger. 2009. Tracing Mercury Contamination from the Idrija Mining
Region (Slovenia) to the Gulf of Trieste Using Hg Isotope Ratio Measurements. Environ. Sci. Technol., 43 (1), 33-39.
Hines, Mark, Horvat, Milena, Faganeli, Jadran. 2000. Mercury biogeochemistry in the Idrija river, Slovenia fromabove the mine into the Gulf Trieste. Environ. Res. 83/A, 129-139.
Horvat, Milena, Covelli, Stefano, Faganeli, Jadran, Logar, Martina, Fajon, Vesna, Rajar, Rudolf, Širca, Andrej, Žagar,
Dušan. 1999. Mercury in contaminated coastal environments; a case study: the Gulf of Trieste. Sci. Total Environ.,
237/238, 43-56.
Ogrinc, Nives, Monperrus, Mathilde, Kotnik, Jože, Fajon, Vesna, Vidimova, Klara, Amouroux, David, Kocman,
David, Tessier, Emmanuel, Žižek, Suzana, Horvat, Milena. 2007. Distribution of mercury and methylmercury in deepsea surficial sediments of the Mediterranean Sea. Mar. Chem. 107/1, 31-48

汚染された沿岸沈殿物中の水銀： 起源選定の新しいアプローチ
沿岸部底質中の水銀汚染は、当初、鉱工業活動などの歴史的な土地利用によるものと考えられた。
水銀採掘は発生源から広範囲の汚染という負の遺産を残した。トリエステ湾はイドリヤ鉱業地区の非効率の採掘方法と不十分な水銀抽出により、大量の水銀が環境に流出した典型的な事例である。輸送
経 路 お よ び 汚 染 沿 岸 部 で の 水 銀 の 変 容 経 路 の 様 々 な 研 究 が 行 わ れ （Horvat et at.,1999, Covelli etal.,2001）、水銀のメチル化、脱メチル化は湾内底質の至る所で起きていることが分かった（Hines et al.,2000）。淡水から海水への勾配は変化に富み、硫酸還元や水銀変容は季節および水深による変動が見られる。水銀動態とメチル化は S サイクリングによって起こるが、沿岸部での脱メチル化はメチル水
銀の蓄積をかなり抑制している可能性がある。通常、メチル水銀濃度は汚染のない環境では底質中の総水銀に相関するが（Ogrinc et al.,2007）、汚染沿岸部では必ずしもそうではなく、環境要因が水銀の最終形態や輸送に大きな役割を果たすことを示唆している。また、河川底質中の水銀同位体組成は上流からの辰砂鉱石と同様であることが分かった。このことから我々は、ソカ/イゾンツォ川の分水地点
からトリエステ湾にいたる底質は、イドリヤ水銀鉱山近くの源流から運ばれた水銀がおそらく北部では 90％以上から湾南部では 45％以下のレベルで、蓄積していると結論づけた。
.

32

NIMD Forum 2012

Minamata City, 26 January 2012

33

NIMD Forum 2012

Minamata City, 26 January 2012

34

NIMD Forum 2012

Minamata City, 26 January 2012

35

NIMD Forum 2012

Minamata City, 26 January 2012

Mercury pollution by many small-scale gold ore smelters in Talawaan River,North Sulawesi, Indonesia.
K. Mori1, M. T. Lasut2, and Y. Yasuda3
1National Institute for Minamata Disease, 4058-18 Hama, Minamata City, Kumamoto 867-0008, Japan

2

Marine Science Department, Faculty of Fisheries and Marine Science, Sam Ratulangi University, North Sulawesi, Jl.

Kampus Unsrat Bahu, Manado 95115, Sulawesi Utara, Indonesia

A new gold ore deposit was found in the Talawaan region, North Sulawesi, Indonesia, in
1996, which was followed by establishment of a great number of small-scale gold ore smelters
upstream in the Talawaan River from 1998 to 2000. The smelters distribute in a triangular-shaped
region around Dimembe, Talawaan and Tatelu Villages, which we named AT (auriferous triangle).
In order to evaluate mercury behavior in the environment after release from the smelters, we
determined the methylmercury (MeHg) as well as total mercury (THg) levels in sediments at morethan 10 stations along the Talawaan River in 2010 and 2011. Furthemore, we conducted to catch
some species of fishes along the stream to clarify the bio-accumulation of mercury
Geometric means of sediment T-Hg and MeHg concentrations in the river were 0.31 µg/g
and 0.92 ng/g, respectively. The maximum THg and MeHg levels were both detected inside AT,
as 3.25 µg/g and 9.20 ng/g. MeHg distributions were highly correlated with those of T-Hg, which
implies that MeHg was generated from the elemental mercury derived from the artisanal gold
mining waste materials. In addition, MeHg concentrations in sediment samples were correlatedwith amounts of ignition loss.
Some carnivorous fish showed high value of Hg, and the accumulation of MeHg in fishes
in this area in the food web was observed. Thus, we infer that metallic mercury diffusion frommining into the environment causes bio-accumulation of MeHg in the Talawaan watershed

インドネシア、北スラウェシ、タラワン川の多くの小規模の金鉱石精練所による水銀汚染
1996 年インドネシア、北スラウェシのタラワン地域で新たな金の鉱床が発見された。そしてその後1998 年から 2000 年にかけてタラワン川上流に非常に多くの小スケールの金鉱石製錬所が作られた。製錬所は、我々が AT（金を産する三角形）と名付けたディメンベ、タラワンそしてタテル村の周りの三角形の地域に分布している。製錬所から放出された後の環境中での水銀の動きを査定するために、
我々は 2010 年から 2011 年までタラワン川に沿って 10 か所以上においてメチル水銀と総水銀レベルを測定した。さらに、我々は 水銀の生物濃縮を明らかにするために流れに沿って幾種類かの魚の捕獲を
指揮した。

36

NIMD Forum 2012

Minamata City, 26 January 2012

川の堆積物の総水銀とメチル水銀濃度の幾何平均値は、それぞれ 0.31 µg/g と 0.92 ng/g であった。総水銀とメチル水銀レベルの最高値は 3.25 µg/g と 9.20 ng/g で、両者ともに AT 内で検出された。メチル
水銀の分布は総水銀の分布と密接な関係があり、メチル水銀は小規模金採鉱からの廃棄物から出てきた元素水銀から作り出されることを示唆している。加えて、堆積物サンプル中のメチル水銀濃度は強熱減量と相互に関連がある。
幾種類かの肉食性魚類は、高い水銀値を示し、この地域における食物連鎖中のメチル水銀の蓄積が観察された。このように我々は鉱山から環境中への金属水銀の拡散がタラワン流域のメチル水銀の生物濃縮を引き起こしていると推論する。

37

NIMD Forum 2012

Minamata City, 26 January 2012

38

NIMD Forum 2012

Minamata City, 26 January 2012

39

NIMD Forum 2012

Minamata City, 26 January 2012

40

NIMD Forum 2012

Minamata City, 26 January 2012

Biomarkers of low level mercury exposure: exposure, impact and genetic
susceptibility
Janja Snoj Tratnik1, Ana Miklavčič1, Simona Jurković Mlakar6, Darja Mazej1,
Mladen Krsnik2, Joško Osredkar2, Fabio Barbone3, Marika Mariuz3, Francesca Valent3, Katia
Sofianou4, Zdravko Spirić5, Janja Marc6, Milena Horvat1
1: “Jožef Stefan” Institute, Department of Environmental Sciences, Ljubljana, Slovenia

2: University Medical Centre Ljubljana, Institute of Clinical Chemistry and Biochemistry, Ljubljana, Slovenia

3: Unit of Hygiene and Epidemiology, University of Udine, Udine, Italy

4: Institute of Child Health, “Aghia Sophia” Children's Hospital, Athens, Greece

5: Institute for Applied Ecology, Oikon ltd., Zagreb, Croatia

6: University of Ljubljana, Faculty of Pharmacy, Department of Clinical Biochemistry, Slovenia

Speciation of mercury (Hg) in biological samples is often disregarded when assessing
methyl mercury (MeHg) exposure. To evaluate how good measure of prenatal low-level exposure to
MeHg is total mercury (THg) concentration, we have assessed the relation between these two
species of mercury in available biological samples. THg was determined in 2153 scalp hair samples,
1654 umbilical cord blood samples, 1081 maternal blood samples, and 1051 breast milk samples inpregnant/lactating women from Slovenia, Croatia, Italy and Greece. MeHg was determined inapprox. 30 % of the samples. As it is well known that selenium (Se) can play a protective role
against Hg toxicity in organisms, Se was determined in all samples together with THg in order tofind an evidence for such connection. In a subset of samples, THg and MeHg were determined alsoin placenta, fetal membranes, meconium and pubic hair. In order to observe gene-environment
interactions, the glutathione S-transferase class - theta 1 (GSTT1) and - mu 1 (GSTM1) genedeletion variants were studied in a subset of participating women. The study was implemented
within the EU 6th framework programme PHIME.
The proportion of MeHg in blood and hair was highly variable (14-100 % in blood and 19100 % in hair) and THg concentration was found liable to overestimate MeHg exposure at low
levels. Hair-to-blood MeHg ratio was highly variable as well (67 to 398). We found whole cord
blood as the most suitable biomarker of prenatal exposure to MeHg. For accurate assessment of
exposure, speciation analyses are required in blood samples, while in hair THg determination is
sufficient as an approximate indicator of exposure due to fish consumption. Maternal scalp hair
MeHg was associated more strongly with blood than pubic hair MeHg. The significance of placenta
as an indicator of MeHg or inorganic Hg exposure is questionable, while meconium was found toindicate MeHg exposure to a certain extent, although a negligible proportion of mercury present as
41

NIMD Forum 2012

Minamata City, 26 January 2012

MeHg in meconium indicated potential demethylation of MeHg in the fetus. Positive and significant
linear correlation between Hg and Se was found in cord blood, maternal blood and breast milk. The
strongest correlation was observed between inorganic Hg and Se in breast milk of the overall
population. Hg and Se were found to be associated positively and significantly also in blood ofchildren aged 6-11 from mercury mine area, but not in children from other areas in Slovenia,
confirming the association of Se with inorganic Hg, which is the predominant species people areexposed to in the contaminated site. Se in maternal and cord blood, but not in milk, wassignificantly correlated with the intake of many food items in pregnancy. The strongest direct
associations regarded cheese and some vegetables (artichokes and fennels). In addition, both Hg
and Se in blood were significantly associated with fish consumption, possibly explaining
correlations between these two elements found in selected biomarkers. Hg in milk was not
associated with the frequency of fish consumption, but with the number of amalgam fillings.
Pregnant women with homozygous deletion of GSTT1 gene showed significantly higher MeHg (butnot total Hg) in cord blood compared to women with the presence of GSTT1 gene. When adjusted to
Se levels in blood, positive and significant associations were observed also for MeHg in maternal
blood. No significant differences of MeHg, THg and Se concentrations between GSTM1 genedeletion variants subgroups were obtained.

低レベル水銀曝露のバイオマーカー： 曝露、影響と遺伝学的感受性

胎児の低濃度メチル水銀曝露の測定において、総水銀濃度が有効な指標であることを示すため、生体試料を用いて総水銀とメチル水銀の関係を調べた。スロベニア、クロアチア、イタリアおよびギリシャの妊婦および授乳中の母親から採取した 2153 件の頭髪試料、1654 件の臍帯血試料、1081 件の母体血液試料、1051 件の母乳試料で総水銀を測定、メチル水銀は約 30％の試料で測定した。セレンは生体
内では水銀毒性に対する防御作用があることで知られているため、その関連性を調べるため、総水銀と合わせて全試料においてセレンを測定した。一部の試料で、胎盤、胎膜、胎便および陰髪についても総水銀とメチル水銀の測定を行った。
血液および毛髪中のメチル水銀の割合はばらつきが大きく（血液 14－100％、毛髪 19－100％）、総水銀濃度は低濃度でのメチル水銀曝露を過大評価しやすいことが分かった。毛髪対血液のメチル水銀の割合もばらつきが大きい（67－398）。全臍帯血が胎児のメチル水銀曝露に最も適した生体指標であることが分かった。メチルまたは無機水銀曝露の指標としては、胎盤の有意性は疑わしいが、胎便については、胎便内のメチル水銀が胎児のメチル水銀の脱メチル化の可能性を示唆するため、ある程度
メチル水銀曝露の指標となることが分かった。臍帯血、母体血、および母乳において、水銀とセレンに有意な正の線形相関が見られた。特に母乳で無機水銀とセレンの高い相関性が見られた。水銀とセレンは、水銀鉱山地区の 6～11 歳の児童の血液にも高い相関性があるが、スロベニアの他の地区の児童にはなく、汚染地区の住民で無機水銀とセレンの関連性が確認できた。

42

NIMD Forum 2012

Minamata City, 26 January 2012

43

NIMD Forum 2012

Minamata City, 26 January 2012

44

NIMD Forum 2012

Minamata City, 26 January 2012

45

NIMD Forum 2012

Minamata City, 26 January 2012

National Environmental Health Survey - Mercury Concentration in Blood andUrine Hyun Jeong Kim, Choong Hee Park
Department of Environmental Health Research, National Institute of Environmental Research

The first stage of Korean National Environmental Health Survey(KoNEHS) Based on
Environmental Health Act(2009) was conducted from 2009 to 2011 in order to find exposure status
and pathways of environmental pollutants.
For annually 2,000 adults over the age of 19, total 6,000 people for three years,
questionnaire for identifying the exposure factors and analysis of the 16 different toxic pollutants inhuman blood and urine were performed. The subjects have been selected among urban, rural andcoastal areas and regions adjacent to air quality monitoring networks by securing representative
concentration of environmental chemicals while considering socio-economical and environmental
exposure impact factors.
As the Results of the analysis, the geometric mean of mercury concentration in blood was
3.08 ug/L and men's concentration, 3.65 ug/L, showed high level than women's, 2.65 ug/L. Mercury
concentration in urine was 0.76 ug/g creatinine and the concentration of the 19~39 age group
showed relatively higher level than others.
The results of this survey will be announced as national official statistics by generating
representative value and reference value of in-vivo environmental toxic substances on general
population and will be a reference to other domestic studies while contributing to the establishment
and evaluation of environmental policy.

韓国環境保健調査 –血液と尿中水銀濃度
環境汚染物質の曝露状と経路を調べるために 2009 年から 2011 年にかけて環境健康法（2009）による第一回韓国全国環境健康調査がおこなわれた。曝露要因を見つけるために毎年 19 歳以上の成人
2,000 人、3 年間で 6,000 人を対象としたアンケート調査をし、血液および尿中における 16 種の有害汚
染物質の分析を行った。
分析の結果、血中における水銀血中濃度の幾何平均は 3.08ug/L であり、男性の濃度は 3.65 ug/Lde で、
女性の 2.65 ug/L より高い値を示した。尿中水銀濃度は 0.76 ug/L クレアチニンで、19 歳から 39 歳までの年齢グループによる濃度が、他のグループのものより比較的高い値を示した。
調査の結果は、体内環境毒性物質の代表値および基準値を算出したのち、全国の公式統計として発表し、ほかの国内研究の参考資料として、また環境政策の評価策定に役立てていきたいと考えている。

46

NIMD Forum 2012

Minamata City, 26 January 2012

47

NIMD Forum 2012

Minamata City, 26 January 2012

48

NIMD Forum 2012

Minamata City, 26 January 2012

49

NIMD Forum 2012

Minamata City, 26 January 2012

Placental transfer of heavy metals and the changes in their body burden in
infants during early-breastfeeding period
Mineshi Sakamoto
Department of Epidemiology, National Institute for Minamata Disease

Fetuses and breast feeding infants depend on their mothers for their nutrition, and they are
exposed to heavy metals such as methylmercury, lead, arsenic, cadmium, and selenium throughplacenta and breast milk of mothers. Our study was performed to investigate the changes in heavy
metals body burden in infants during early breastfeeding period in comparison with the metals
transfer through the placenta. Blood samples were collected from 16 mother-child pairs; cord blood
immediately after birth, maternal blood at 1 day after parturition, and infant blood at 3 months(most of the infants were breast-fed). Fetal levels of mercury, selenium, arsenic, and lead strongly
reflected the maternal levels, and the placental transfer of methylmercury was especially high.
However, the methylmercury level in infants after 3 months declined to about 50% of that in infants
at birth. Selenium showed the similar but gentle changes to methylmercury. Se/Hg molar ratio incord RBCs was significantly higher than that in maternal RBCs and the ratio in infants returned tosimilar ratio in maternal RBCs after 3 months. For lead and arsenic, the placenta barrier seemed toprotect fetuses to some extent, and little change was observed during the breast-feeding period. The
placenta barrier seemed to work strongest against cadmium among the metals, and the level was
kept low during lactation. If no particular contamination of any metal exists in the environmental
setting, metal exposure through breastfeeding need not be a concern.

重金属の経胎盤移動と授乳早期の児における体内蓄積変動
胎児期及び乳児期に児は母親の栄養に依存し、これらの金属も母体経由で児へ移行するが、各金属で児への異なる曝露パターンを示した。特に妊娠後期の胎児脳は MeHg に対する感受性が高いと言われている上に、MeHg は母親より高い濃度で蓄積するので注意が必要であるが、通常での魚介類摂取における MeHg 曝露は比較的低濃度であることに加え、乳児期には生後 3 ケ月で血中 MeHg 濃度が半減するので胎児期ほどの注意は必要ないと考えられる。Cd は胎盤透過性が非常に低く、血中 Cd 濃度
は乳児期にも低いまま推移するという独特のパターンを示した。他の金属は、胎盤がこれら金属 の胎児への移行をある程度制限する役割を果たしており、更に、乳児期においては大きな血中濃度の変動は無い。
以上より、胎児期には MeHg の曝露 に関する注意が必要であるが、特段の汚染が授乳中の母親に無い限り、乳児期には特定の金属が児に特に高濃度で蓄積する危険性は少ないと考えられた。

50

NIMD Forum 2012

Minamata City, 26 January 2012

51

NIMD Forum 2012

Minamata City, 26 January 2012

52

NIMD Forum 2012

Minamata City, 26 January 2012

The blood mercury concentration in a coastal area and four cases ofneuropsychological abnormal findings in children with high blood methylmercury concentration in Korea
Young-Seoub Hong
Department of Preventive Medicine, Dong-A University, Busan, Korea

Many of previous studies reported that high blood mercury concentration increases thefrequency of neural developmental disorder caused by mercury poisoning particularly in children
because the development of brain and the nervous system is active during childhood. The healtheffects of mercury that have been reported in Korea are mostly occupational poisoning, and there
have been few cases of health problems caused by non-occupational factors. We would like tosuggest the level of the blood methyl-mercury concentration of the residents of coastal area, Korea,
and introduce the observed four cases of neuro-psychological abnormal findings that were believed
to have been induced by methyl-mercury. We performed thorough examination for four children
whose mercury concentration(16.6 ㎍/ℓ, 15.4 ㎍/ℓ, 17.4 ㎍/ℓ, 20.6 ㎍/ℓ) in the body exceeded theinternational standard in a community epidemiological survey on mercury exposure, and observed
neuropsychological abnormal findings such as mild mental retardation, attention deficit
hyperactivity disorder, and low attention concentration, so here we reported the cases. Based on thiscase report, efforts should be made to conduct expanded research as well as to reduce children’s
exposure to mercury and prevent related health problems in them.

韓国における沿岸地域の血中水銀濃度と高い血中メチル水銀濃度を示した子供達 4 ケースの神経心理学的異常の検出
これまでの研究では、児童期には神経系統や脳の発達が活発であることから、児童の血中水銀濃度が高ければ、水銀中毒による神経発達障害が起こりやすいと報告されている。韓国で報告されている
水銀の健康への影響は、そのほとんどが職業中毒であり、非職業要因による健康問題のケースはほとんど報告されていない。
我々は、体内水銀濃度が水銀曝露に関する国際基準を上回る 4 名の子供に水銀曝露に関する疫学的調査を行い（16.6 ug/L, 15.4 ug/L, 17.4 ug/L, 20.6 ug/L）、軽度の知的障害、注意力欠陥、多動性障害、注意集中力障害等の精神心理学異常所見を認めた。よってこのケースを報告する。
また今後は子供の水銀曝露や関連の健康障害を減らすために、この報告に基づいて更なる研究を重ねていくつもりである。

53

NIMD Forum 2012

Minamata City, 26 January 2012

54

NIMD Forum 2012

Minamata City, 26 January 2012

55

NIMD Forum 2012

Minamata City, 26 January 2012

56

NIMD Forum 2012

Minamata City, 26 January 2012

Health effects of mercury in Almadén, the world's largest mercury mining
district
Pablo Higueras1; Santiago Español2; José M. Esbrí1; Sergi Díez3
1: Instituto de Geología Aplicada, Universidad de Castilla-La Mancha, Spain

2: Fundación Almadén

3: Environmental Chemistry Department, IDAEA-CSIC, Barcelona, Spain.

Almadén mercury mining district (south-central Spain) has been the world’s largest
producer of this element. The district includes a number of different mines and prospects, but themain source has been the Almadén mine, around which the town grown, so that general population
has been always in close contact with the mine products, including mercury vapors spreading in theurban area. The three main sources of local mercury pollution have been the mine itself (affecting
mainly to the mine workers), the metallurgical activity, and the main mine dump. Human exposure
to mercury may occur via a variety of pathways, including occupational uses. In particular the town
inhabitants have suffered intense exposure to mercury vapors, with the presence of other toxic
species such as methylmercury only in relation with heavily polluted minor streams and in products(calcines) from metallurgy. Undoubtedly, the most intense exposure to mercury has been the one
suffered by miners, historically affected by hydrargyrism, the disease related to inhalation of
gaseous mercury. The incidence of the disease declined sharply in the 50’s, thanks to reducing
miner’s work from 20 to 8 days per month, and in recent times (1980-2003), with preventive healthmeasures undertaken by the company medical staff. The mercury levels in the hair of residents
living in Almadén showed higher levels than another area far away. Even though the fishconsumption frequency is an important parameter, exposure to mercury due to residence is a key
determinant that causes that the population most at risk is located in the vicinity of mining activities.

世界最大規模水銀鉱山地帯アルマデンにおける水銀の健康影響

アルマデン水銀鉱山地区（スペイン中南部）は世界最大の生産圏である。この地区にはたくさんの異なる鉱山があるが、しかしその主たるものはアルマデン鉱山で、その周辺には町が発達したため、一般住民は水銀蒸気を含む鉱山からの生産物と密接なかかわりがあり、主たる水銀汚染源は鉱山そのものであり（主に鉱山労働者に影響を与えている）、精錬作業と主たる鉱山からの廃棄物である。住民も水銀蒸気への曝露に苦しんできた。最も強い水銀曝露のケースは抗夫であり、水銀ガスの吸入に関連した病気である。この病気のケースは 50 年代に急激に減少しが、これは、抗夫の労働時間が、月に 20 日間から 8 日間に減ったことと、会社の医療スタッフによる予防策による。アルマデンの住民の高い毛髪水銀レベルも鉱山活動に起因すると考えられる。

57

NIMD Forum 2012

Minamata City, 26 January 2012

58

NIMD Forum 2012

Minamata City, 26 January 2012

59

NIMD Forum 2012

Minamata City, 26 January 2012

60

NIMD Forum 2012

Minamata City, 26 January 2012

NIMD Forum 2012発行 環境省

国立水俣病総合研究センター

Published by National Institute for Minamata Disease, Ministry of the Environment, Japan

〒867-0008

熊本県水俣市浜 4058-18

TEL: 0966-63-3111
FAX: 0966-61-1145

4058-18, Hama, Minamata, Kumamoto 867-0008, Japan
TEL: +81-966-63-3111
FAX: +81-966-61-1145
http://www.nimd.go.jp

問い合わせ先：国際・総合研究部
Inquiry: Department of International Affairs and Environmental Sciences
kokusai@nimd.go.jp

61