Environmental Engineering Reference
In-Depth Information
For the other two cities, the maximum values exceed the alert threshold for Pb,
by 1.4 times in Bucharest soils and by 1.7 times for Iassy soils. Accordingly, from
an abundance point of view, lead is the dominant chemical element and is strongly
influenced both by traffic and industrial emissions.
In addition to absolute values and statistical parameters of the heavy metal con-
tents, the values of two abundance indexes: pedogeochemical index (PAI) and geo-
chemical index (GAI) were also calculated. They are representing the ratio between
the metal content medium value in analyzed soils and the normal content value in
soils, clark value. Clark is representing the medium content of a chemical element
in the lithosphere. Analysis of Fig.
1
clearly reveals that the two indicator values are
small and very small, ranging round the one value for Cr, Cu, Mn and Ni.
This fact proves the predominant geogenic origin of these chemical elements.
Higher values of the pedogeochemical index were recorded for Co, attesting concen-
trations of this chemical element in the soil. On the contrary, the IAG and IAP values
for Cd, Zn, and especially Pb, have been striking the wrong note. Very high values
of these two indicators denote the major contribution as anthropogenic, which
enhance very much these chemical element contents, as compared to lithological and
pedologic background (Fig.
1
). The heavy metal abundance in urban soils situated
lengthways the main streets in the three investigated Romanian cities is superior to
BM
11.78
7.09
I
2.24
1.34
B
3.30
1.99
BM
52.90
49.60
I
10.13
9.50
B
7.93
7.43
BM
1.35
0.46
I
2.10
0.72
B
1.85
0.64
BM
1.04
0.52
I
1.04
PAI
GAI
0.52
B
1.01
0.51
BM
1.00
3.34
I
1.15
0.49
B
2.55
1.08
BM
0.66
0.28
I
1.03
0.37
B
0.97
0.35
BM
4.60
1.28
I
5.20
1.44
B
4.60
1.28
BM
5.33
12.30
I
5.66
13.10
B
7.33
16.90
Fig. 1
Values of pedogeochemical (PAI) and geochemical abundance index (GAI) of heavy metals in
urban soils situated lengthways the main streets of Bucharest (B), Iassy (I) and Baia Mare (BM) cities
