EarthworksKn

owle

dge

& R

esea

rch

ISSU

E 13

Nov

eem

ber 2

001 ■ EDITORIAL

page 2

■ RECOVERING LOST GOLDStudies in Zimbabwe and Guyanapages 2 and 3

■ SMALL-SCALE MININGModel schemes of assistancepages 4 and 5

■ LOW-COST LIMELime for small-scale farming(FarmLime)page 6

■ LOCAL PHOSPHATEResources for sustainable developmentpage 7

■ IODINE DEFICIENCYEnvironmental controlspage 8

Cover picture: Tantalite small-scale mining inNigeriaKevin D’Souza, © Wardell Armstrong

Issue 13 November 20012

EARTHWORKS

Editorial

This issue of Earthworks focuses on two mainthemes: small-scale mining (SSM) and food-related issues in developing countries. All

articles relate to studies undertaken under DFID’sKnowledge & Research (KaR) Programme.

Two important articles are presented on SSM.Both draw attention to the extreme poverty existingin this sector and attempt to develop approaches toremedy this. In the first of these studies, Dr MikeStyles of BGS presents the results of a project aimedat improving practices in the small-scale gold miningsector. The work demonstrates how simple but

appropriate local technology can dramaticallyincrease gold recovery while at the same time bene-fiting the environment. The second account, fromKevin D’Souza of Wardell Armstrong, describes amore general analysis undertaken of the SSM sector,designed to develop a model scheme to assist small-scale miners. This stresses the range of factors thatneed to be addressed if policies are to be successfuland sustained. Interestingly, both studies concludethat an effective way to induce change is to demon-strate the benefits of new techniques through pilotschemes as an example for others to follow.

The remaining articles relate to food and health.Two of these are concerned with improving the

productivity of farmland through the use of locallyavailable soil supplements. Dr Don Appleton of BGSdescribes how local phosphate rock can be used as afertiliser in nutrient-poor tropical soils depleted byerosion and leaching. In a companion account, CliveMitchell also from BGS describes how agriculturallime from local deposits can be used to neutralise theeffects of acidified soils.

Finally, Dr Chris Johnson (BGS) reports onsolutions aimed at increasing the availability of iodinein the local environment. His study is an attempt todocument the behaviour of iodine in the natural envi-ronment as a basis for considering sustainable alterna-tives to the iodinisation of table salt.

Small-scale and artisanal gold mining is a vitalsource of livelihood for millions of poor peoplein developing countries. The efficiency of gold

recovery in small-scale mining (SSM) is notoriouslypoor (reputedly around 30–40%), as evidenced by thefact that tailings are reworked many times. Thisproject is aimed at improving gold recovery andencouraging more environmentally friendly methods,thereby achieving a more sustainable livelihood and asafer and cleaner environment for the miners and thelocal communities. The project has been carried out inpartnership with the Geology and Mines Commissionin Guyana, and ITDG in the UK and Zimbabwe.

Small-scale gold mining is difficult to preciselydefine but covers a range of activities from smallgroups of miners with limited finance and equipmentto the hapless artisan trying to make a living withwhatever comes to hand. The countries selected forthis study, Guyana and Zimbabwe, span the range butthis article focuses on Guyana. The first part of theproject was a review and feasibility phase thatincluded desk and field surveys, and covered bothtechnical and sociological factors.

The technical review found that although manytechniques are used for gold recovery in large goldmines, few are really suitable for SSM. Sluicing,

which is already widely used, can be relativelyefficient but only where the gold grains are not toosmall. However, it is very difficult to obtain informa-tion on grain-size distribution of gold in mining areas,and testing has to be a vital factor before recommen-dations on mining techniques can be made. InGuyana, for example, it was widely perceived thatmuch of the gold was fine-grained and that loss of thiswas the main cause of poor recovery. However, arange of tests carried out on the alluvial gravel ore, thesluice box concentrates and the sluice box tailingsshowed that: (1) there was very little very fine-grainedgold in the ore (always less than 10%) and (2) losseswere across the spectrum of grain sizes but involvedcoarse gold in many cases. The perceived problemwith fine-grained gold was, in fact, a groundlessrumour: a well set-up sluice box with a more efficientgold-trapping mechanism should be able to recoverperhaps 80% of the gold. Ironically, their boxes werequite good at trapping the finer gold, but unfortunatelyperhaps there was very little of it present in thisinstance.

The surveys identified that miners’ knowledgecame mainly from copying their employers or neigh-bours but few really knew why they did it in a particu-lar way or had any understanding of the basic princi-ples of mineral processing. To improve recoveries,technology needed to be changed. The surveys alsoconcluded that the best way to transfer improved tech-nology to the miners was to carry out demonstrationsand refit sluice boxes with better equipment. At thesame time, staff from the Mines Commission weretrained in ore testing and sluice box assessments,means of improvement, and giving advice to miners.Teaching materials for the mines officers to supple-ment their knowledge and enable them to carry outsustained assistance to miners, were also prepared.

By chance, a Canadian environmental project wasalso giving assistance to gold miners, and the projectsagreed to collaborate. The initial joint demonstrationwas carried out in the Mahdia area in 1998. The rec-ommended method of improvement was to install aCanadian-devised system of gold trapping. This

Recovering the lost gold of the developing worldMike Styles, British Geological Survey, Project R7120

Typical sluice box with large rifles and black cocoa mats.

Mik

e St

yles

, BGS

© N

ERC

3Issue 13 November 2001

EARTHWORKS

Current projectsR7116, G1 Evaluating possible uses ofZimbabwean phosphate based wastes. (Ottos Ruskulis, Intermediate Technology)

R7120, G1 Recovering the lost gold of the developingworld. (Mike Styles, British Geological Survey)

R7181, G1 Design and pilot implementation of amodel scheme of assistance to small-scale miners.(Jeffrey Smith, Wardell Armstrong)

R7354, G1 Mercury-free coal-gold agglomeration(CGA) process for gold. (Professor MichaelMingos, Imperial College of Science Technologyand Medicine)

R7370, G1 Local phosphate resources for sustainable agriculture. (Don Appleton, BritishGeological Survey)

R7410, G1 Low-cost lime for small-scale farming(FARMLIME). (Clive Mitchell, British GeologicalSurvey)

R7416, G1 Sustaining communities through minewaste reclamation. (David Harrison, BritishGeological Survey)

R7118, G2 Cost-effective evaluation of hazardsfrom mine waste. (Ben Klinck, British GeologicalSurvey)

R7411, G2 Environmental controls in iodine deficiency disorders. (Chris Johnson, BritishGeological Survey)

R7815, G2 Landslide risk assessment in the ruralaccess sector. (Gareth Hearn, Scott, WilsonKirkpatrick & Co Ltd)

R7198, G5 Appropriate technology for low-costgeological mapping. (Eugene O’Connor, BritishGeological Survey)

R7199, G5 Strategies and systems for maximisinggeoscience data value. (John Laxton, BritishGeological Survey)

R7816, G5 Glacial hazard risk minimisation inrural environments. (John Reynolds, ReynoldsGeo-Sciences Ltd)

R8035, G5 Self-help toolkit to construct a geo-science metadata system. (John Laxton, BritishGeological Survey)

R8036, G2 Socially sustainable developmentstrategy. (Stephen Davis, Congo-Online Ltd)

KaR websiteFor more information on KaR geoscienceprojects visit www.bgs.ac.uk/dfid-kar–geoscience

involved replacing the traditional black cocoa mats,sometimes with large Hungarian riffles, that were inalmost universal use, with vinyl ‘Nomad’ mats andshallower, expanded metal riffles. The width andslope of the box was adjusted to give optimum flowconditions. At that time these mats and riffles werevery difficult to obtain in Guyana and had to bespecially imported. The first refit was on the sluicebox of one of the best-known and most well-organised miners, on the assumption that other minerswere more likely to copy a local role model. Tests byRandy Clarkson, the Canadian mining engineerinvolved, showed that efficiency increased fromaround 60% (surprisingly high) to around 80% as aresult of refitting.

A survey of the take-up of technology, along withfurther demonstrations, was carried out in 2001 in theKonawaruk area, some 50 km from Mahdia. Thisshowed that of the miners that had been working inthe Mahdia area in 1998, perhaps 100 groups, themajority had now moved to other areas. However,those that remained and many in the Konawaruk area,were mostly using the improved technology, to agreater or lesser extent. Most surprising was the factthat the better materials were now widely availablelocally and could be purchased over the counter at asmall mining store in the interior. Many miners hadmade the capital outlay but not got the details quiteright, which shows the need for follow-up instructionand on-going advice from mines officers.

The financial benefits were even greater thaninitially expected: the pay-back period as a result ofimproved gold recovery was estimated to be as littleas two weeks to perhaps one month. The pile of theblack mats wears away very quickly, which partlyaccounts for their poor performance and they have to

be replaced every month or so. By contrast, the vinylmats, although costing twice as much, wear muchmore slowly and those fitted in 1998 were still in use16 months later.

This project found that there is less resistance tochange than might be expected, and that miners willadopt new techniques provided they are appropriateand affordable. Convince a few and the rest willcopy. In Guyana, the perceived best way to carry outgold sluicing has changed in two years due to theinfluence of technical assistance projects. The mainenvironmental benefits are less reworking of tailingsand damage to the local environs. Better gold-trapping means there is no need to use mercury inthe pits and sluice boxes, as a good mat does the jobefficiently. However, it is very difficult to persuadethem not to use mercury or use retorts at the stagewhere they clean up the concentrate of gold andheavy minerals recovered on the sluice box. To theminers, speed of recovery and transparency, so thatthe whole team of miners can see what is happening,are far more important than possible long-termhealth dangers.

Large sluices in Guyana.

Mik

e St

yles

, BGS

© N

ERC

For further informationcontact:

Dr M T Styles, British Geological Survey,Keyworth, Nottingham NG12 5GG,United Kingdom

Tel: +44 (0)115 936 3414Email: mts@bgs.ac.uk

Issue 13 November 20014

EARTHWORKS

Much has been written about the harmfuleffects of small-scale mining (SSM) on com-munities and the environment. Of the various

factors associated with SSM, the one common denom-inator is the abject poverty of the sector. It should beremembered that many individuals only operate in thissector because they have no other choice. It is alsotrue that many of the social and environmental conse-quences (e.g. child labour, lack of education, sub-standard sanitation, deforestation, river silting,mercury pollution, etc.) come about, not throughdeliberate, malicious intent but rather out of ignoranceand lack of financial resources.

Wardell Armstrong (incorporating CSMAConsultants), in conjunction with the BGS, was com-missioned by DFID to carry out an analysis of theglobal SSM sector aimed at developing a modelscheme of assistance that could be implemented bycentral authorities and multilateral donors. A newapproach is needed if the desperate poverty that existswithin the SSM community worldwide is to becombated. The end purpose is to improve the qualityof life of miners and communities by advancing struc-tured policies aimed at the sustainable development ofthe sector.

A number of components make up a successfulSSM project, all of which must be in place if SSM isto contribute real benefits to the miners, the local pop-ulation, and the national government. The focus of anyreform should be to provide financial empowerment tosmall-scale miners that will then act as a catalyst toother miners to improve their financial position. Thebest inducement to act within the legal structure, withdue regard to health, safety and the environment, is tosee other miners who have benefited financially fromworking within the legislation and have been aided bythe government to do so.

The approach therefore should be all-encompass-ing, dealing with each of the relevant issues that arefundamental to the sector. An integrated approachshould give the organisational and legal aspects, man-agement techniques, and environmental and socialissues at least the same priority as technical issues orthe supply of equipment. An assistance programmethat seeks to solve one aspect but ignores the others,while perhaps well-intentioned, is unlikely to have anylasting impact. Above all, if there exists a genuinedesire to draw the SSM sector into the formal businesscommunity, there must be an acceptance that financialempowerment and gain is part of the process. The aim

should be to encourage the miners to be entrepreneurs,not to constrain and hinder them. Although assistanceprogrammes should be essentially non-discriminatory,there may be a rationale for trying to identify a smallgroup of miners to aid initially in order that they canbe used as an example for others to follow. Thisapproach might be appropriate in concentratinglimited resources on a key objective to avoid thembeing spread too thinly over a wide area, therebyachieving little.

ConclusionsThe research identified a number of problems relatingto SSM and the funding of aid programmes in thissector.i The attitude of host governments to the sector

varies considerably often due to reaction to recentevents rather than the result of a rational develop-ment of strategy.

ii While a great deal of aid money is spent on thesector by donor agencies, the projects sponsoredare usually aimed at specific topics and rarelyaddress the sector as a whole and particularly thepoverty issues.

iii Many of the projects that are funded are unsustain-able in the long term in that they only last as longas there is aid money; once this is exhausted theprojects cease.

iv The projects that are undertaken are oftendesigned to control and regulate the sector. Theyare often studies rather than technical activities.

v There is widespread duplication of projects withlittle thought of budget-sharing or information-exchange. This has often resulted in poor utilisa-tion of resources.

vi There appears to be a general reluctance, on thepart of certain aid agencies to divulge information.This makes the determination of the success ofprojects extremely difficult.

vii There is little co-ordination between aid agencies,either on matters of funding or exchange oftechnical findings. Often, this appears to bebecause the aid agencies have their own specificagendas.

viii There are very few NGOs working in the sector,unlike other sectors such as agriculture. Thismeans that there is little historical precedent.

One of the main findings of the project is that theproblems traditionally associated with SSM occur as adirect result of the poverty associated with the sector.Often, the miners appear to have been effectively disen-

A model scheme of assistance to small-scale minersKevin D’Souza, Senior Mining Engineer, Wardell Armstrong,

Project R7181

Diamond mining in Ghana.

Kevi

n D’

Souz

a ©

War

dell

Arm

stro

ng

“... many of the social and environmental conse-quences (e.g. child labour, lack of education, sub-standard sanitation, deforestation, river silting,

mercury pollution, etc.) come about, not throughdeliberate, malicious intent but rather out of

ignorance and lack of financial resources...”

EARTHWORKS

5Issue 13 November 2001

franchised by governments and donors alike; the scaleof the problem should not be underestimated. Thisscenario may be reversing as a result of the NationalStrategy for Sustainable Development (NSDD) policythat all countries have to target for by the year 2005.

Our initial report concludes that if governmentsand agencies wish to make a real difference to thesituation, they must begin to address all the issues thataffect the sector, not just the ones that are currently invogue or politically correct. There needs to be a movetowards a culture of wealth-generation and an attempt

to draw the SSM sector into the legitimate socialfabric of the country. Many of the present negativeimpacts of SSM could be mitigated by a concertedattempt to introduce these types of policies. Not onlywill they enhance the quality of life but they will alsodemonstrate the benefits of working within the legalframework rather than outside it.

The primary issues in this study fundamental toimproving the general management, production, safetyand environmental performances of the SSM sectorsin the developing countries are:

● defining a model government institution, unit orset-up to handle and/or manage the SSM sector

● establishing and enabling an appropriate legisla-tive framework and licensing scheme for SSMoperations

● defining relevant and consistent occupationalhealth and safety standards and practices, andproviding appropriate training on these issues

● establishing appropriate and realistic environmen-tal protection principles and practices

● addressing the social welfare and gender issuesthat plague the sector

● delineating or defining the overall mineralpotential for SSM exploitation, addressing the reli-ability and suitability of the deposit in terms ofreserves and mineralogy

● establishing a self-sustaining technical assistanceand training scheme for small-scale miners

● providing a viable and efficient financing andbanking scheme for small-scale miners

● providing a simple and effective marketing systemfor SSM products.

Kevi

n D’

Souz

a ©

War

dell

Arm

stro

ng

Gold mining in the Philipines.

Kevi

n D’

Souz

a ©

War

dell

Arm

stro

ng

For further informationcontact:

Kevin P C J D'Souza, Wardell Armstrong,Lancaster Building, Newcastle-under-Lyme,Staffordshire ST5 1PQ, United Kingdom

Tel: +44 (0)1782 612626e-mail: kdsouza@wardell-armstrong.comWebsite: www.wardell-armstrong.com

Gold mining in the Philipines.

Issue 13 November 20016

EARTHWORKS

The occurrence of acidified soils in many develop-ing countries often leads to poor crop yields, asituation which could be easily remedied if agri-

cultural lime (aglime) were used. However, subsis-tence farmers often fail to do so, in part due to lack ofknowledge but also because aglime is too expensive.Production of low-cost aglime from suitable carbonateresources within farming districts would improve theaccess of small-scale farmers to this valuable additive.The aim of the FarmLime project therefore is twofold:first, to investigate low-cost means of producingaglime using appropriate local technology, and secondto conduct crop trials to demonstrate its effectiveness.

Since the first report on FarmLime (Earthworks,November 1999), at which time the project had beenrunning barely three months, a truly multidisciplinaryteam of collaborators has been established includingagronomists, chemists, engineers, geologists andsocial scientists. The project activities are co-ordinatedby the British Geological Survey (BGS) in conjunc-tion with the staff of the Zambian Geological SurveyDepartment (GSD) and the University of Zambia(UNZA) as follows:● Project leader:Clive Mitchell (BGS)● Socio-economic survey:Diana Banda (UNZA

Department of Agricultural Economics) andMlotha Damaseke (Programme AgainstMalnutrition, PAM)

● Carbonate resource assessment: BonifaceMuibeya and David Kapindula (GSD)

● Lime production research:Professor StephenSimukanga (UNZA School of Mines) and Moffat

Mwanza (UNZA Technology DevelopmentAdvisory Unit, TDAU)

● Crop trials: Dr Victor Shitumbanuma (UNZASchool of Agricultural Science)

● Project consultant:Briton Walker (UK).The socio-economic survey was intended to 'set thescene' in the farming districts by understanding theconstraints affecting the use of aglime. At the sametime, small-scale farmers willing to become involvedin the crop trials element of the project needed to beidentified. It quickly became apparent that the socio-economic and crop trials teams would benefit fromworking closely together. This study confirmed thatsmall-scale farmers experience problems both inobtaining and affording aglime. Simple solutions tothis were forthcoming from the farmers themselves:bulk buying of aglime by local co-operatives; makingaglime available in smaller bags (25kg); substitutionof part of their fertiliser for aglime; and bartering foraglime with maize or other products.

The carbonate resource assessment focused ondolomite deposits in Solwezi (North-WesternProvince) and Mkushi (Central Province), Zambia.Samples were collected on a simple grid pattern andevaluated in the laboratories of the GSD.Determinations were carried out for: neutralisingvalue (NV) expressed as calcium carbonate equivalent(CCE); nutrient contents expressed as calcium andmagnesium oxide contents; reactivity; and 'grindabil-ity'. As a result, the dolomite in both areas was foundto be suitable for use as aglime. A private companyhas since set up an aglime production operation(HiQwalime) in Mkushi (although so far this mainlysupplies commercial farmers).

The lime production study involved tests on bulksamples of dolomite from Mkushi using an adaptationof a hammer mill designed originally for maize milling.Initial field trials were carried out with the assistance ofinmates from Munsakamba open prison (near Mkushi)who (with no irony) were set to breaking rocks tosupply feed material for the mill! Based on these trials,a modified mill with strengthened hammers, additionalwear plates and a smaller product screen has been takenback to Mkushi and Solwezi for final milling trials. Theground dolomite produced using the mill is used asaglime for the crop trials.

The crop trials involve small-scale farmers in theMkushi area identified by the local agriculturalextension officer as operating well-run farms andrespected in the local community. The crop trials aresituated in the Chalata and Kasansama agriculturalcamps, as well as the Mkushi Farm Training Centre.

The trials include both maize, as it is a staple, andgroundnuts, as they respond well to changes in soilacidity. The soil in these areas has a pH of 4.6 to 4.9and therefore requires 200 to 450 kg of aglime perhectare for neutralisation of acidity. The crop trials usea conservation technique known as ‘pot hole’ farming(also referred to as ‘precision farming’) in whichaglime or fertiliser are placed in regularly spacedholes rather than being spread over the entire area asin the more traditional ‘ridge’ farming. As only 7% ofthe farming land is used, the amount of inputsrequired is reduced. The method has been demon-strated to radically improve farmers’ crop yields.Typical maize yield using ridge farming (withoutaglime) is less than 2 tonnes per hectare, whereasusing ‘pot hole’ farming (with aglime) production hasbeen reported at well over 10 tonnes per hectare,which exceeds the performance of even the large-scalecommercial farmers! The crop trials will continue forfive growing seasons to fully demonstrate the benefitsof using aglime to small-scale farmers.

By spring 2002, the research phase of the projectwill be completed and the dissemination/demonstra-tion phase will commence. FarmLime will be holdingworkshops throughout the SADC region starting withLusaka in June 2002 and progressing to othercountries, such as Kenya, Namibia, Malawi,Mozambique and Tanzania, over the next few years.

Low-cost lime for small-scale farming(FarmLime)Clive Mitchell, British Geological Survey, Project R7410

Carbonate resource assessment.

Cliv

e M

itche

ll, B

GS ©

NER

C

Hammer mill in action.

Cliv

e M

itche

ll, B

GS ©

NER

C

For further informationcontact:

Clive Mitchell, British Geological Survey, Keyworth, Nottingham, NG12 5GG,United Kingdom

Tel: +44 (0)115 936 3257E-mail: cjmi@bgs.ac.ukWebsite: www.bgs.ac.uk/omer/farmlime.html

EARTHWORKS

7Issue 13 November 2001

ADFID overview of soil fertility issues in sub-Saharan Africa has highlighted the inherent lownutrient status of weathered tropical soils, as

well as the loss of nutrients through erosion andleaching. Phosphorus is a key nutrient. Low soil-nutrient status can be rectified by increased inorganicfertiliser use. However, this is constrained by the lackof adequate knowledge regarding, amongst otherthings, the potential for the production of fertilisermaterials from local phosphate rock resources, andnon-industrial techniques for increasing the solubilityof native phosphate rock. For forest/agricultureinterface production systems, the application of a widerange of rock-based phosphate sources should be con-sidered for dealing with the degradation of naturalresources at the forest margin.

The various stakeholders concerned may not beadequately aware of locally available phosphate rockresources, nor their agronomic potential as a low-costsource of phosphate for the enhancement of soilfertility and productive capacity of relatively poor,smallholder farmers. A need therefore exists to ensurethat the use and development of local resources is con-sidered as an option for restoring the P-status and pro-ductive capacity of degraded soils. The DFID-fundedKaR project Local Phosphate Resources forSustainable Development will produce three regional

reviews (covering sub-Saharan Africa, Asia, and LatinAmerica) which will provide advisers with a concisesummary of national and regional information on localphosphate resources.

The first section of the African report containsregional or generic reviews of:● phosphate mineral resources of sub-Saharan

Africa, including information on phosphate rockand phosphate fertiliser production, consumption,and export

● phosphate rock products and processing options● estimated investment required for mining, infra-

structure and processing options● constraints for utilisation of phosphate rock

resources● environmental constraints related to

heavy/hazardous elements contained in the rockphosphates or their by-products

● existing or anticipated direct use of phosphate rockin agriculture including general results ofagronomic and economic assessments and

● the role of phosphate rock in strategies for dealingwith soil fertility.

The second section of the report comprises thirty-onecountry profiles, each of which summarises:● quantity, quality and location of local phosphate

rock deposits/sources in each country (maps

indicate the location of the phosphate resourcesand major transport routes)

● past and current phosphate rock production,including export as intermediate/raw materials andlocal use in agriculture and

● agronomic and agro-economic assessments ofrock phosphates and associated phosphate fer-tiliser products, including information on the soiltypes and crops likely to show a positive responseto direct application of rock phosphate fertilisers.

Phosphate rocks in sub-Saharan Africa are of twomajor types. (1) Sedimentary deposits of phosphaterock formed in coastal marine or lacustrine environ-ments as the result of biogenic activity. These are pre-dominant in western Africa. (2) Phosphate depositsassociated with alkaline and carbonatite igneouscomplexes, mostly of Jurassic, Cretaceous andTertiary age. Most of the phosphate deposits insouthern and eastern Africa are of this type.

The distinction between sedimentary and igneousphosphate rocks may not be of major importance ifthese are beneficiated and used for manufacturingchemical fertilisers. However, the low reactivity ofigneous phosphate rock generally makes it unsuitablefor use as a direct-application fertiliser, other than inspecial circumstances such as tea plants grown onvery acid soils in areas with high rainfall. Extensivelateritisation of phosphatic sedimentary rocks hasproduced aluminium phosphate deposits at a numberof localities of which the most important is the Pallodeposit in Senegal. Relatively small deposits of batand bird guano occur at a number of localities.

Local phosphate resources for sustainable developmentDon Appleton, British Geological Survey, Project R7370

Location of phosphate deposits in sub-Saharan African.

Deposit typeGuanoIgneousMetamorphicSedimentary

For further informationcontact:

Dr J D Appleton, British Geological Survey,Keyworth, Nottingham NG12 5GG,United Kingdom

Tel: +44 (0)115 936 3207Email: jda@bgs.ac.uk

Tunduma

NkombwaIsoka

Mpika

ChipataChilembwe

KaluweRufunsa

Kapiri Mposhi

Chambishi

Ndola

LusakaNambala Mission

Mumbwa North

Livingstone

Location of phosphate rock resources in Zambia.

Issue 13 November 20018

EARTHWORKS

Other DFID Newsletters inthe same series

ENERGYTRANSPORTURBANISATIONWATER

Contact addresses

Earthworks, David Greenbaum,British Geological Survey,Keyworth, Nottingham NG12 5GG, UKTel. +44 (0) 115 936 3224Fax. +44 (0) 115 936 3474E-mail: dgree@bgs.ac.ukWeb: www.bgs.ac.uk/dfid-kar-geoscience

Energy, Clive Caffall,ETSU,156 Harwell, Didcot, Oxfordshire OX11 0QJ, UKTel. +44 (0) 1235 433591Fax. +44 (0) 1235 433548E-mail: clive.caffall@aeat.co.ukWeb: www.etsu.com/dfid-kar-energy/

Transport, Linda Parsley,International Division, TRL Limited,Old Wokingham Road,Crowthorne, Berkshire RG45 6AU, UKTel. +44 (0) 1344 770551Fax. +44 (0) 1344 770356E-mail: international_enquiries@trl.co.ukWeb: www.transport-links.org/transport_links/newsletter/newsletter.asp

Urbanisation,Darren Saywell,Water, Engineering and Development Centre,Loughborough University of Technology,Loughborough, Leicestershire LE11 3TU, UKTel. +44 (0) 1509 222885Fax. +44 (0) 1509 211079E-mail: wedc@lboro.ac.ukWeb: www.lboro.ac.uk/garnet/UrbanKaR/dfid-kar-urban.html

Water, Geoff Pearce,HR Wallingford Limited,Howberry Park, Wallingford, Oxon OX10 8BA, UKTel. +44 (0) 1491 822439Fax +44 (0) 1491 826352E-mail: g.pearce@hrwallingford.co.ukWeb: www.hrwallingford.co.uk/projects/dfid-kar-water.html

Earthworks is published by:The British Geological Survey on behalf of the Department for International Development.

The views expressed are not necessarily thoseof DFID.

Editor: David GreenbaumSub Editor: Joanna ThomasDesign: Adrian MinksProduction: James RaynerPrinted by: Hawthornes, NottinghamPRINTED ON RECYCLED PAPER

Iodine is an essential trace element for humans andanimals. A deficiency of iodine in the diet will leadto iodine deficiency disorders (IDD), the most strik-

ingly obvious manifestation of which is goitre — anenlargement of the thyroid gland in the neck. Infantsborn to severely iodine-deficient mothers may bementally retarded (cretinism); indeed, iodine defi-ciency is reported to be the world’s most commoncause of mental retardation and brain damage. Indeveloped countries and many parts of the third world,this problem has been tackled successfully usingmedical intervention techniques such as the iodinisa-tion of table salt. However, such intervention requirescontinuous input to local communities from outsideagencies and, moreover, is only successful where thelocal communities are prepared to accept the methodsused. For example, very poor communities will oftencontinue to use salt made from traditional sourcessimply because they cannot afford to buy table salt.

This current project is looking at environmentalsolutions to increase the availability of iodine in thelocal environment. During the past year, the projecthas collected samples of soil, water and foodstuffsfrom an iodine-deficient area of Xinjiang Province,China. Here, an American-sponsored project (KiwanisInternational) has been adding iodine to the environ-ment through dripping potassium iodate into irrigationwaters. The ongoing study will provide informationon how iodine migrates through the food chain toprovide this essential trace element in our diet. Resultsto date suggest that, whilst the dripping programmeresults in a significant short-term increase in theiodine status of the local population, in the long term

the added iodine does not appear to have a longresidence time in the soil. This emphasises the need toestablish which factors are responsible for fixingiodine in the environment and what agriculturalpractices best ensure that iodine gets transferred intocrops.

A comprehensive database of iodine’s behaviourin the environment is being prepared and will beavailable together with other information on theproject’s website.

Environmental controls in iodine deficiency disorders (IDD)Dr Chris Johnson, British Geological Survey, Project R7411

Soil sampling in Xinjiang province, China.

Dr A

lex

Stew

art,

Wirr

al H

ealth

Aut

horit

y

For further informationcontact:

Dr Chris Johnson, British Geological Survey,Keyworth, Nottingham NG12 5GG,United Kingdom

Tel: +44 (0)115 936 3372Email: ccj@bgs.ac.ukWebsite: www.bgs.ac.uk/dfid-kar-geoscience/idd/

UK Data Protection ActWe hold the Earthworks mailing list as a computerdatabase. Unless we hear to the contrary weassume that all the named recipients of thisnewsletter have no objection to their details beingrecorded in this way.