Countermeasures for Agricultural Land Soil

Pollution in Hyogo Prefecture

June 25, 2014Hyogo Prefectural Government

Agricultural & Environmental Affairs DepartmentAgriculture, Forestry & Fisheries Bureau

Agricultural Improvement DivisionEnvironmental Development type Agriculture

Promotion Group

Overview of “Agricultural Land Soil Pollution Prevention Law”Objects　　　　 The Law aims at the prevention of the production of agricultural

crops and livestock which are feared to be harmful to human health or the prevention of the obstacle of the growth of agricultural crops and others to be helpful for the protection of national health or the preservation of a good living environment, by establishment of necessary policies which are useful for the prevention of agricultural land soil pollution caused by specific harmful substances or the elimination and which are useful for the rationalization of utilization of polluted agricultural land

Mechanism• Designate the areas where soil contamination is found as agricultural

land soil pollution policy areas (Hereinafter referred to as ‘Policy Areas’)based on the continuous monitoring by prefectures, make countermeasures and implement remedial measures like soil dressing etc.

• “Protection of human health” (Cadmium) & “preventing growth inhibition of agricultural crops” (Copper & Arsenic) could be the reasons for designation

• Set 0.4ppm for cadmium to ensure consistency with the specification standard of Food Sanitation Act (for rice)

• When the countermeasures are completed, confirm the effect by investigation of Policy Areas and cancel the designation

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3

Continuous

monitoring

Fact-finding investigation of soil pollution (prefecture)

Confirm contamination

Local governme

nt Central government

Sources of

pollution

CostPollution Control

Public Works Cost Allocation Law

Law Concerning Special Government Financial Measures for Pollution

Control Projects

Designated hazardous substances

Designation standard for agricultural land soil

pollutionRemarks

Cadmium and its compounds

Concentration in brown rice exceeds 0.4mg/kg(0.4ppm)

Protection of human health

Copper and its compounds

Concentration in soil125mg/kg(125ppm) or more

Preventing growth inhibition of agricultural crops

Arsenic and its compounds

Concentration in soil15mg/kg(15ppm) or more

Preventing growth inhibition of agricultural crops

The governor can decide within the range of 10-20ppm depending on the natural condition

Mechanisms of “Agricultural Land Soil Pollution Prevention Law”

Designate agricultural land soil pollution policy areas (prefecture)

Design agricultural land soil pollution policy project (prefecture)

Implement improvement work Cancel

designation (prefecture)

Enforced by prefecture or municipalities

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History of Agricultural Land Soil Pollution Prevention in Hyogo

Prefecture• Agricultural land soil is polluted by effluent of suspended or

abandoned mines, by industrial waste water or by falling dust (Mine effluent and factory waste water are the main sources in Hyogo prefecture)

• There are several hundreds of suspended or abandoned mines, mainly in Chugoku mountain region in Hyogo prefecture

• In 1970, the Ministry of Agriculture, Forestry and Fisheries conducted a nationwide investigation of suspended or abandoned mines etc. and surrounding areas. As a part of this nationwide investigation, water pollution special investigation or special investigation for harmful substances were carried out and revealed the contamination condition of hazardous substances like cadmium

• For five years from 1971 to 1976, the Ministry further implemented Agricultural Land Soil Pollution General Investigation (General investigation for heavy metals) and 104 points were monitored in Hyogo prefecture

• Hyogo prefecture has been actively engaged in solving the cadmium pollution of agricultural land soil from the early stage

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Current Soil Pollution Status of Hyogo Prefecture

• Thanks to the countermeasures taken from 1972, all the listed agricultural land soil pollution policy areas of Hyogo prefecture were canceled as of May 2, 2001, when K town was de-registered for completion of remediation of Cadmium

• 5 Areas were designated and executed remediation measures like soil dressing etc. Some areas conducted countermeasures without being designated

• As for the surrounding area of Ikuno Mine, conducted brown rice and soil survey as part of Cadmium etc. concentration investigation (observation type investigation) and gave guidance to thoroughly execute farming method to inhibit Cadmium absorption like flooding management etc.

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Products suspected to lower concentration Products suspected to higher concentration

Transfer of products

Varieties suspected to lower concentration Varieties suspected to higher concentration

In case transfer of product is difficult

Transfer of varieties

Cd concentration of edible part vary in different varieties

Suppress absorption by

applying alkaline materials &

fertilizer

The reduction ratio of Cd concentration in proportion to pH elevation in soil

Susceptible to decline Not susceptible to decline

Cleaning method by plants & dressing soil etc.

Products & Varieties with less risk of absorption

　×Make soil to proper condition（Apply alkaline materials &

fertilizer ）

The Concept of Risk Management

Target pH 6.5-7.0

Cd absorption differs depending on agricultural products or varieties

In case transfer of varieties is difficult

Cd concentration vary in different

products

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Current measures taken by Hyogo Prefecture

1 Observe progress by investigating Cadmium concentration etc.

2 Give guidance of Farming method to suppress absorption of Cadmium

3 Conduct “Cadmium Test” based on Food Sanitation Act

4 Promote Agricultural Land Soil Cleaning Method by Plants Project

1 Investigation of Cadmium Concentration etc.

• The pollution expanded in a wide range for the surrounding area of Ikuno Mine, including the neighboring Akenobe Mine. Thus, even after the completion of the remediation, observation survey of Cd concentration of soil and brown rice (standing crop; the condition before harvest in the field ) is continuously conducted to monitor the contamination condition. 12 sampling points every year

• Following the Implementation Guideline of Cadmium Concentration etc. Investigation, got previous permission of the related municipalities, sought comments of the relevant municipality and drafted the investigation plan

• The designed investigation plan is notified to the Director of Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries and ask for the cooperation to the investigation

• Based on the Implementation Guideline of Cadmium Concentration etc. Investigation, the result is made public (published in official written reports of the prefecture)

　項 目 　 　 　採 取 時 期 　 　 　分 析 項 目 　備 考

　玄 米 収穫前（１週間以内） Ｃｄ 外部委託

　土 壌 玄米採取時 ( )Ｃｄ 可溶態 外部委託 8

Items

Brown rice

soil

Sampling time Analytic Items remarks

Before harvest (within 1 week)

Cd Out sourcing

When taking samples of brown rice

Cd (in soluble form) Out sourcing

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2 Guidance of Farming method to suppress absorption of Cadmium

• As for regions where no measures, like dressing soil construction work to permanently stabilize its safety is taken, give guidance to invest soil improvement materials (Calcium Carbonate or Bentonite, which is a viscous mineral) or farming technology to suppress cadmium absorption by thorough flooding management of paddy rice etc.

• Give guidance and advice to the cultivation calendar making by Agricultural Cooperatives

• The prefectural government, municipalities and Agricultural Cooperatives integrally guide cultivation method, make tour of paddy fields and alert the attention through the Radio Broadcasting system

• From Feb. 28, 2011, Cadmium specification standard of Food Sanitation Act has been strengthened. Thoroughly notify to farmers the farming technology to suppress cadmium absorption via related institutions and organization and promote voluntary inspection before shipping at production area with Agricultural Cooperatives taking the lead

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Alkaline materials (Lime materials) 【 Paddy rice 】

Cd concentration in soil 　Ａ： 1.0 Ｂ： 2.6

If concentration is around 1ppm, pH7 level enables to suppress Cd concentration of brown rice without any flooding management

0.0

0.5

1.0

1.5

2.0

2.5

4 4.5 5 5.5 6 6.5 7 7.5 8pH土壌

(ppm

)玄

米カ

ドミ

ウム

濃度

0 521 +4.35ｙ＝－ ． ｘ r = -0.866

0 248 +1.93ｙ＝－ ． ｘ r = -0.981

B土壌

土壌 Ａ

If elevate the pH level of soil, Cd concentration of brown rice is in decline→Alkaline materials are effective

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Drying upFlooding Management against Cd (3 weeks before & after ear emergence

Flooding Management

■intermittent irrigation

◆Flooding Management

Flooding management is very effective in paddy rice

Cd concentration in brown rice may exceed standard

Cd concentration in soil may be high but that in brown rice is below standard

0.0

0.5

1.0

1.5

6.0 6.1 6.2 6.3土壌ｐＨ

0.4

玄米カドミウム濃度

ppm

間断かん水

湛水管理

＊ Result with Cd concentration in soil 2.6ppm

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3 “Cadmium Test” based on Food Sanitation Act

• In compliance with the “Hyogo Prefectural Plans for the Monitoring of and Guidance on Food Sanitation” based on Food Sanitation Act, Health & Welfare Office conducts removal test centering for areas having a history of Cadmium pollution to secure safety of circulating rice

• In case 0.4ppm or more is detected in the test, it is necessary to take measures to determine the cause etc.

　　→　 Call related institutions and establish countermeasures meeting

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4 Promote Agricultural Land Soil Cleaning Method by Plant ProjectImplement in the area where cadmium is detected more than 0.4ppm or more in brown rice

　　　 In contrast with the soil dressing construction work, the above method can mitigate the Cadmium concentration in soil in lower cost and expect the decline of risk of agricultural products with exceeding standard produced not temporarily but further in the future as well

1) Experimental proof of Soil cleaning method by plants　　 As one of the countermeasures against Cadmium soil pollution of

agricultural land, a soil cleaning method using Cadmium high absorption plants to lower Cadmium concentration in soil (phytoremediation) is put toward practical use. Experiment to prove the effect of plant cleaning method is implemented at local paddy fields

After one year application of this cleaning method, Cadmium concentration (in soluble form) of plowed soil decreased by 10-26% and exceeded the normally expected value of 10%

　　　2) Experimental proof of less Cadmium absorption type rice　　 Compared with the popular variety “Koshihikari”, there is a variety

expected to lower the risk because of its character to absorb less Cadmium.

After taking the same management of experimental paddy field for the

first year, the cadmium concentration of the new variety was lower than that of “Koshihikari”.

　　 The new variety is expected to be the main crop in this area in the future

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Problems: Takes a lot of years & Treatment of the harvested crops

Cleaning Method by Plants (Phytoremediation)

Cd concentration in soil decreased

Soil condition suitable for more absorption

LowMoisture

Low pH

　長香穀（高吸収イネ）

Let the special plants absorb and take them out

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Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

Ｃｄ

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Low Cd Absorption Variety (paddy rice)

Hardly absorb Cadmium despite high Cd concentration in soil and water saving conditions

The yield & quality are almost equivalent to those of the popular “Koshihikari” variety

Soil Cd ： 0.35 ～1.4ppm

イオンビーム育種（農環研）

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In conclusion

Agricultural Improvement Division

Training session & public relations activities

Agriculture & Horticulture Division

Recommend varieties

Extension Center

Guidance to cultivation management

Agricultural Technology Institute

Establish countermeasures technology

Municipalities

Crop design

　 JA ZEN-NOH

Guidance & Coordination

Farming siteProducer

Liaison Committee

• As for the countermeasures for agricultural land soil pollution, the related institutions like municipalities, Agricultural Cooperatives and producers should cooperate in both hardware side (e.g. soil dressing construction work) and software side (e.g. Making cultivation calendar, making tour of paddy fields or guidance of cultivation method)

• Because soil dressing work costs a lot, it is necessary to make a comprehensive study taking into consideration cleaning method by plants or cultivation of crop varieties with less absorption of Cadmium as options