Impacts  of  past  mining  activities  on  the  Environment  in  Kabwe Town,  Zambia
Imasiku  A.  Nyambe1,2,  Meki  Chirwa2 and  Bernard  Chaziya1,  1Integrated  Water  Resources  Management  Centre,  University  of  Zambia  2Geology  Department,  University  of  Zambia,  Box  32379,  Lusaka,  Zambia

IGCP  /  Sida Projects  594  and  6006  CLOSING  WORKSHOP,  Praha,  Czech  Republic
26-­28th May,  2014  – Kampai 2017

Outline  of  Presentation
Background  History
Previous  Studies
Assessment  of  Results
Conclusion
IGCP  /  Sida Projects  594  and  6006  CLOSING  WORKSHOP,  Praha,  Czech  Republic
26-­28th May,  2014

Kabwe is capital Central Province ofZambia
Total Population – 250,000

Background History• Lead – Zinc Mine opened in 1904.
• Over the years mining included
open cast & underground, mineralprocessing, smelting and refining withsulphide orebodies, pyrite, sphalerite,
galena – minor covellite, chalcopyrite,chalcocite, bornite & tetrahedrite• Mine officially closed in 1994
• Rehabilitation and Decommissioning
Plan in 1995

Substantial informal setting of 35% of Kabwe’s total population livein unplanned settlement

Soils
According to the FAO/UNESCO (1997) classification ofsoils, the acrisols are most abundant in the Kabwe area.
These are Fe-rich tropical soils without development of acemented horizon. Podsols are less abundant, being formedin areas underlain by shales and quartzites.
Clayey vertisols occur in areas covered by marshes(dambos).
These soils develop a network of cracks on their surface
during the dry season (Kříbek et al. 2009).

GEOLOGICAL MAP OF ZAMBIA

Sampled area

The sulphide cores of the Kabwe orebodies generally comprise
pyrite, sphalerite and galena, with minor covellite, chalcopyrite,chalcocite, bornite and tetrahedrite. Sphalerite is generallydominant over other ore minerals.

The distributions of the orebodies are strongly fault controlled, and/orcontrolled by lithological competence barriers between schistose andmassive dolomite sectors of the Kabwe Dolomite.

Table 1. Zn and Pb contents of Kabwe orebodies (Water
Management Consultants Ltd, 2005)
Orebody

Sulphide   oreOxidized  oreZn  (%) Pb (%} Zn/Pb

Zn  (%) Pb  (%) Zn/Pb

133.2

24.7

1.2

19.2

14.8

1.3

2

-­

-­

-­

20.7

2.1

9.85

5-­6

33.7

14.1

2.39

17.3

6.5

2.0

8

63.4

0.9

70.4

-­

-­

-­

X

33.9

25.0

1.36

20.3

13.4

1.5

Mapping and Assessing the Environmental and Health Impacts of a closed Kabwe
Mine, Zambia

The most comprehensive previous work carried out in the area was thatedited by Kribek et. al (2008), who mapped and assessed the impacts ofmining and mineral processing on the environment and human health in theKabwe area of Central Province of Zambia under the Project of theDevelopment Co-operation Programme of the Czech Republic No.
RP/3/2008 for the years 2008-2010.
Other studies included that of Tembo, Sichilongo and Cernak (2006) who
studied the distribution of copper, lead, cadmium and zinc concentrations insoils around Kabwe Town in Zambia
An earlier scoping and design study by Water Management Consultants Ltd(2005) was part of the Copperbelt Environmental Project that was extended
to Kabwe Town followed the completion of privatization of the ZCCM in2000.

The Scoping and Design Study, Phase 1 for Kabwe was therefore
undertaken, and from this, ZCCM-IH carried out the cleaning of theKabwe Town area and pulling down of the mining infrastructure.

Kabwe Old  Mine  LocationZCCM  –IH  2006-­2009• Kabwe Scopingand Design Study(KSDS);

Yoshinori Ikenaka, 2009

Hokkaido University

Effect  of  mining  activity  on  wild  and  domestic  animals:  Case  study  of  lead  -­zink mining  area,  Kabwe,  Zambiav Phase 1

Ø Determine extent andmagnitude of contaminationby lead and other toxic
substancesv Phase 2

Ø Characterize main pathwaysof lead exposure to residents

They collected 101 soil	  samples	  v Phase 3and	  animal	  samples	  from	  blood	  of	  Ø A revised closure andcattle,	  mice	  and	  organs	  of	  chicken	  rehabilitation plan for themine site, including measures investigate	  metal	  pollution	  of	  As,	  to reduce human exposure
Cd,	  Cr,	  Cu	  Co,	  Ni,	  Pb and	  Zn.	  
to leadASSESSMENT OF RESULTSZCCM	  –IH	  2006-­‐2009 Kabwe Scoping	  and	  Design	  Study

Results	  of	  Lead	  in	  Soil

Source of Pollution: KabweMine Plant formed an intense exposuresource.

Kabwe	  Scoping	  and	  Design	  Study	  after	  Joseph	  Makumba,	  2013
• KSDS showed highBlood Lead Levels (BLL)
above WHO standards(<10 µg/dl), in
population living near
the former mining area.
• Medically, children
between ages 0-7 years
arethe most vulnerable
to effects of lead
exposure.
• BLL are represented inclasses of 1 to 5 basedon concentration oflead in blood

Rehabilitation of Kabwe Mine Plant Area

• All defunct plant
infrastructure
demolished andcleared.
• Public health hazards
the emanation ofcontamination arisingfrom human access toand/or from Kabwe
mine site removed.
••••Community water supply improvements
Establishment of Environmental Public Information Centres
Incidents of children playing at lead contaminated dumps wereprevalent and contributed to elevation of blood lead in children,
lead free play parks for children were constructed.
Greening of households to provide vegetative coverOne  of  the  clinics  constructed  for  lead  care  support

Improved
Information onLead

Sampling points of the soil in Kabwe (n = 101, May 2009)

Kabwe

Pb & Zn mineto Lusaka (T2)

3 km
Measured metal concentrations in soil（As, Cd, Co,Cr, Cu, Ni, Pb, Zn）
17Zinc	  (Zn),	  Lead	  (Pb)	  and	  Copper	  (Cu)	  concentrations	  in	  Kabwe	  soils

Not	  only	   Zn	  and	  Pb,	  but	  Cu	  concentration	  	  also	  	   exceeded	  the	  	  recommended	   value

Zn

Pb

Cu

Zn

Pb

Cu

Range

5  – 91,000

9  – 51,000

2  – 5,000  Median

610

280

40

Recommended

50-­120

120

70

18

Analysis of	  metal	  distributions	  by	  GIS
mine
mine

Pb
Cd
Cadmium(Cd)

Co Low
Cd
Cobalt  (Co)

Zinc  (Zn)Zn

Zn
ArsenicAs
(As)

As
Ni
Nickel  (Ni)

Cu

CrCu
Copper(Cu)

Cr High
Chromium  (Cr)

Pb
Lead  (Pb)

It	  is	  clear	  that	  high	  concentration	  of	  metals	  	  (Pb,	  Zn,	  Cd,	  As,	  Cu)	  were	  distributed	  around	  the	  mine.	  

mineThese	  results	   clearly	  suggest	  that	   not	  only	  Pb and	  Zn,	  but	  Cd,	  As	  and	  Cu	  also	  	  originate	  from	  mining	  activity,	  and	  are	  distributed	  around	  the	  mine. 19

Kidney	  Pb levels	  in	  Kabwe~Toxicological	  effects	  of	  Pb~Collected  around  100  rats  from  various  area  in  Zambia  include  Kabwe

Kidney・Pb

25  mg/kg:  diagnostic  level

AAB

2.5  mg/kg:
Bhistopathologicalthreshold

Kabwe

Copperbelt  Lusaka
Tukey-­Kramer,  P<0.05•

While	  non	  exceeded	  the	  diagnostic	  level	  (25	  mg/kg),	  several	  Kabwe rats	  had	  Pb levels	  higher	  than	  the	  histopathological threshold	  (2.5	  mg/kg). 20

Concentration	  of	  Pb and	  Cd	  in	  the	  tissue	  of	  cattle	  is	  become	  high	  near	  the	  mining	  area

Near  the  mine

Near  the  mine21

2008  PROJECT OBJECTIVES
Project  of  the  Dev.  Assist.  Programme  of  the  Czech  Republic  to  the  Republic  of  Zambia for  the  years  2008-­2010■■■■

Determination  of  the  extent  and  magnitude  of  contamination  by  lead  and  Zinc  other  metals  Kabwe
environment
Evaluation  of  the  gastric  availability  and  plant-­
accessibility  of  lead,  zinc  and  cadmium.  
Assessment  of  harmful  properties  and  ecotoxicity  of  mining-­derived  residues.
Formulation  of  appropriate  measures  for  the  reduction  of  human  health  risk.

2013 Study

Assessment of impacts ofabandoned mines on theenvironment and human health inAfrica as a follow-up toIGCP/SIDA Projects 594 /606
Worked on Kabwe Old Mine
where previous mining activities
still exist such as tailings, as well
as new activities by undertaking:(i) Survey mapping following the work
carried out by Czech – Zambia
Geological surveys (2007 -2008),
ZCCM- IH (2006-2009) and Hokkaido
U. (2012) – to add to the existing data:(ii) Collecting more samples – including
Groundwater ; and(iii)Outreach and educational activities tocommunities and mining companies.

2013 StudyFig.  1.  
Sampling  Points  for  2008  and  2013  studies

2  Methods
Soil  (top  &  subsurface),  stream  sediment,   vegetation,  and  SW  &  GW  samples  were  collected  (Figure  1)

Soil (Top & Sub.) = 29 samples

Surface / Groundwater = 23 S

Groundwater = 23 S

Stream Sediment = 11 S

Vegetation = 36 S

Rhizosphere at vegetation roots = 9 S

Precipitate = 1 S
Total = 109 Samples

Project of the Development Assistance Programme of the Czech Republic to the Republic of Zambia for the years 2008-2010

Extent and magnitude of soil contamination in the Kabwe area
Lead is particularly harmful to thebrain, nervous system and kidney.
Children are especially vulnerable.

Canadian   soil  quality  guideline  value

Lead(mg/kg)

Industrial  land  use

600

Commercial   land  use

260

Residential   land  use

140

Agricultural  land  use70

Formulation of appropriate measures for the reduction ofhuman health risk: long-term goals
Environmental subdivision of the Kabwe area

Dambo

EXPLANATION
Zone  I
Area  of  mining  andmineral  processing
activities,  including
waste  disposal  sites
Zone  II
Extremely  contami-­nated  and  densely
populated  areas  Zone  IIIStrongly  contami-­nated  and  densely
populated  areas  Zone  IV
Contaminatedarea

1

MAKULULUKASANDAMAKANCLANYAMA  Kabwe  Earth  Movers
aggregate  plantPrůmyslový
Industrial
areal
area
Průmyslové
Industrial
odpadywastes

Mutwe  Wansofu

RAILWAY

Sable  Zinc  Plc.
tailings  dam

Mine  Canal

Fe-­Mn  smelter(active)

Dambo

Pb-­Zn  smelter(abandoned)

2013  Assessment  of    Soil  Contamination
Pb =  23  -­ >  10  000ppmZn  =  53.6  (P1)  -­ >10  000ppm  Cu  =  9.72  -­ 3744.71ppm  (P2)and  500  – 3500ppm  around  Mine
Cd  ~  20  -­ 200ppm  around  the  old   mine

Sampling  locations  from  the  2008  and  2013  study

Levels of metals
along a soil profile
from SE to NW

Stream  Sediment  Assessment
Lead =  553.87  >  10,000ppm
Zinc  =  3343.5  >  10,  000  ppm  Copper  =  21.36  -­ 10  000  ppm.  
For example, Heavy
metal concentrations
in stream sediments
along the Canal SEto NWAssessment  of  Surface  water  contamination

Though  Cond.  &  DO  varied,  pH  was  between  5  and  7

Figure 8: Surface
water parameters alongcanal profile (RED)Concentration (ppb)

For  instance,  zinc  and  lead  concentrations  were  observed  to  increase  to  levels  of  between  500,000  ppb  to  around  2,000,000  ppb  in  this  area  (Fig.,  9)

ZnCdFeCoCuNiMg

CrPbAsHg

Figure  9:  Metal  concentrations  along  sampling  locations  on  a  water  profile  (2013  Data).  
(SE)
W2W5W6W8W9W10W16W17W18 (NW)W19Sampling Locations (Profile Approx. 3,460 m)

Assessment  of  Groundwater  contamination
Lead    ~  189.6ppb  Zinc    ~  52  837ppb  Other  metals  (Cu,  Fe  and  Ca)    showed  significant  increases  within  the  vicinity   of  the  old  mine  area

When  compared  to  WHO  and  Zambia  Bureau  of  Standards  (ZABS),   all  the  metal  concentrations  in  groundwater  samples  were  below  these  standards.  Assessment   of  Vegetation    contamination  green  profile

Zinc  ~  8,000  ppm,  Lead  &  Mercury  ~  2,000  ppb

9000

2000

8000

1800
1600

1400

6000

1200

5000

1000

4000

800

3000

600

2000
1000
0(SE)
P1

P2P3

P4P5P6

P10 P11 P17 (NW)
P18

Sampling Locations

Cu

Amounts (ppb)

Amounts (ppm)

7000

Pb

Zn
NiCo
Mn
As

400

Cd200

Cr0Hg

Vegetation  Contamination
Zinc  ppm

Lead  ppm

Copper  ppm

Locality

Cassava  Leaves
Resp.  Rhizosphere Soil

273.6
102.3

34.40
86.31

14.40
12.88

P1P1

Cassava  Tubers
Resp.  Rhizosphere Soil
Cassava  Tuber  Peels
Sweet  Potatoes
Resp.  Rhizosphere Soil

59.7
53.60
41.00
26.3
94.8

6.49
23.95
10.87
7.55
74.07

11.15
16.84
7.28
-­
-­

P1P1P1P1P1

Tomato  Leaves
Resp.  Rhizosphere Soil

158.9
1516.9These  crops  take  up  heavy  metals  from  polluted  and  disrupted  agricultural  land.  

P6P6

Vegetation  Contamination
Zinc  ppm

BlurushResp.  Rhizosphere Soil
Lemon Grass
Resp.  Rhizosphere Soil

Lead  ppm

Copper  ppm

Local.

5550.20 2771.85 2084.78
10,000 10,000 560.70>10,000 1075.68 176.07
1783.10 1596.20
46.11

P4P4P4P4Such plants could be used to clean both the canals and thedisrupted agricultural land of Kabwe.
Metal  concentrations  in  all  edible  vegetation  samples  taken  was  below  WHO  and  ZABS  standards  in  the  sampled  vegetation

Conclusion
In  the  2013  study,  Pb concentrations  were  around  20,000  ppm  near  the  old  Zinc  and  Lead  mine  area,  whereas  the  highest  zinc  concentrations  were  over  10,000  ppm  in  the  same  area  as  was  sampled  in  2008.  
Most  other  locations  sampled  in  2013  had  similar  measurements  as  the  2008  study  e.g.  Zinc  concentration  at  P3  east  of  the  old  mine  area  (this  study),  revealed  similar  results  of  2960.5  ppm  (2013)  and  around  2700  ppm  in  2008.  For  copper,  it  was  observed  that  there  was  some  significant  rise  from  around  320  ppm  in  2008  to  3458.48  ppm  within  the  sampling  area,  (P7  –Figure  1),  located  north-­east  of  the  active  iron-­manganese  smelter.
The  same  sampling  location  also  had  an  increased  concentration  of  iron  from  around  9.0%  in  2008  to  16.0%  in  2013.  
Manganese  was  found  to  be  in  excess  of  7397  ppm  in  2013  from  the  2008  value  of  around  4000  ppm  at  sampling  location  near  P3.

It  is  noted  that  iron  and  manganese  concentrations  had  increased  significantly   from  the  concentrations  obtained  by  Kříbek  et  al.,  2008.  

This is attributed
to the active ironmanganesesmelter within thesame area.

Overall,  despite  the  Government  clean-­up  of  the  Kabwe area,  concentration  values  for  metals  (lead,  zinc,  copper,  iron  and  manganese)  are  either  at  the  same  levels  or  increasing  due  to  continued  processing  of  metal  ores  by  the  new  operations  who  still  use  the  same  facilities  for  disposal  .  

It  is  recommended  to  be  addressed  by  all  stakeholders  through  enforcement  of  existing  legislation  and  re-­introduction  of  rehabilitation  programmes.

Outreach programmes to raise public awareness inlocal schools, municipalities and communities should
be encouraged