Determination of metal concentrations in vegetation, soil, dust, and water in the vicinity of a cement factory in North West province, South Africa

ABSTRACT

On

a per capita

basis,

ce

me

nt is

the second most w

idely cons

umed produ

ct in the world

a

nd

its

de

mand is

increasing globall

y

due

to popul

ation g

ro

wth

a

nd urbanisation.

Manufacturin

g

plants

p

roduce cement kiln du

st

(CKD) as o

ne of the

by-products whil

e co

a

l

provides

the

do

minant

ene

rgy source in

the ma

nuf

ac

turin

g process. Vario

us

me

ta

ls a

re found

in CKD and some o

f these

are mi

cro

nutrie

nts w

ith pote

ntia

ll

y

toxi

c effects. If these are

present in la

rge quantiti

es

,

th

e

y

pose

a d

irect threa

t to vegeta

tio

n

,

a

nimals and

huma

ns.

T

he a

im

o

f

thi

s stud

y

was

to

qu

anti

fy a se

lecte

d

numbe

r

of trace

meta

l

co

nce

ntrati

o

ns

v

egetatio

n

,

soil

,

dust

a

nd

wate

r

samples

near

a ceme

nt manufac

turing

pl

ant in the North West

Province

.

T

hirty

-o

ne sam

ples at

vari

o

us

dis

ta

nces

J]·o

m

approximate

ly

500m to 2700m

fro

m

whe

re

th

e ceme

nt

factory

is situated

,

were co

llected. In

a

ddition

,

s

im

il

a

r

sampl

es (except f

o

r

water) were ta

ken fro

m a co

ntro

l site situated

72 kilo

me

tres in a

north-western directio

n f

rom the

factory

. The wa

te

r contro

l sample was collected

fro

m the

Ditsobo

tl

a municipa

l wate

r supply.

Soil.

pla

nt and

dust sa

mp

les as well

as th

e sedime

nt fro

m the water

sample were acid di

gested

to

obta

in to

ta

l me

ta

l co

nce

ntratio

ns

.

The aci

d

di

gested sampl

es

we

re

ana

lyzed

fo

r

selec

te

d me

ta

l

conce

ntr

ati

ons

us

ing the

IC

P-M

S.

T

he

re

lat

ions

hip betwee

n

soil metal

concentratio

ns and

parti

c

le s

ize

dis

trib

utio

n

as well

as

the

re

l

atio

nship

between dust co

nce

ntra

tions a

nd

Ca

conce

ntrati

ons was est

a

bli

shed to

de

termine

the

link with the

presence on a C

M

P

in the a

rea. T

he

contro

l sa

mples,

re

fe

re

nce sta

nda

rds and results from

s

imi

l

ar research perf

o

rm

ed were

used

to

compare w

ith meta

l conce

ntratio

ns fo

und in thi

s study.

T

he study

revea

led

th

at Ni a

nd

C

u

concentra

tions are

hi

gher in the s

ilt fract

ion

of

the so

il

whil

st

V.

Co.

Zn

and Pb

in the

s

ilt

f

ractio

n

are onl

y

marginall

y

hi

ghe

r tha

n th

e compl

ete so

il

sample.

O

nly C

r

a

nd M

n

conce

ntrati

ons were

hi

gher in

soil

sampl

es

than th

e contro

l

and reference

v

a

lues.

w

hile

m

eta

l co

nce

ntra

ti

on

s

for

C

r

,

Cu

,

Pb

and Mn

were

hig

he

r in the

dust

sam

p

l

es tha

n

th

e

contro

l

and th

e Emi

ss

io

n

Limit

Value

(E

L

V).

Mo

reove

r

,

me

ta

l co

ncentrati

o

ns

in

the

v

egetat

ion

sa

mples are

not

a conce

rn

as th

e concentratio

ns a

re

lower than refere

nce values

.

C

ad

mi

um

and

As

levels are of no

co

ncern in thi

s study a

rea especia

lly s

ince dust samples had

undetectably low levels

.

The

condition

of

the

environment

m relation

to

pollution

from

the cement factor

y

was

established. Although

so

me metal

s

re

vea

led lower concentration

s,

th

e s

tud

y

demon

s

trated

th

e

pot

e

ntial

of

m

e

tal

contam

inati

on

particularly Ni

,

Mn and

Cr

to the

environment vis-a

v

i

s

on

the

s

urrounding

vege

tation

,

animals and

possibly

on

humans.

was

th

e

r

efo

r

e

r

eco

mmended that

E

L

V

limit

s

for

South Africa should

be

established

and monitor

e

d

for

ce

m

e

nt f

ac

tori

es

in

So

uth

Africa coupled with

s

u

s

tainable land managem

e

nt policie

s

.