70
P. Lazo et al.
5.1 Chromium, Cr
Cr is naturally occurring and widely distributed in the earth’s crust. It is a common
constituent of many minerals (UNEP 2013). Cr is emitted to the atmosphere via
natural sources such as windblown dust, forest fires, and anthropogenic sources such
as mining, smelting, refining, fossil fuel combustion, and waste incineration (ATSDR
2005, 2012). Chromium contents in moss samples varied from 1.47 to 262 mg kg
−1
(INAA Analysis), with an average concentration of 27 mg kg
−1 . It shows a high
variation (CV % = 168%) and high positive values of skeweness and kurtosis that
indicate high disparity of the concentration data with a tendency of skewed right.
High differences were observed among different areas (Fig. 5.1) that indicate the
effects of different factors. The spatial analysis plot of Cr (linear model) (Fig. 5.1)
shows a high increase from the south to the north direction of the country (Cr = 3.7
+ 0.928 × n, n represents the number of sampling site) that is characterized by a
high slope in the linear model (b = 0.928, very close to the maximum value of b =
1). This trend with very high slope in regression line, is dominately affected by the
significant Cr maximum concentration at the site 42 (Bulqiza area).
High Cr concentrations were found in St. 11, 13, 14, 24, 27, 41, 42, 43 and 47
positioned in the south, central part and in the North-East of the country. The highest
Cr content was found in St. 42, Bulqiza region that is the area of main Cr deposits
of Albania. High Cr contents in moss samples of St. 41, 43 and 47, respectively at
Librazhd, Burrel and Bujan, are strongly linked with geogenic factors of these areas
that are known for their chromite deposits and Cr mining industry. These findings
indicate the important role of soil dust fine mineral particles as the main source of Cr
in these areas. Moss samples at the areas with very high of certain trace elements in
45
40
35
30
25
20
15
10
5
1
250
200
150
100
50
0
MAPE
255.09
MAD
23.07
MSD
1609.73
Accuracy Measures
n
Cr
Actual
Fits
Variable
Spatial Analysis Plot for Cr
Linear Trend Model
Cr = 3.7 + 0.928×n
Fig. 5.1 Spatial analysis plot of Cr
P. Lazo et al.
5.1 Chromium, Cr
Cr is naturally occurring and widely distributed in the earth’s crust. It is a common
constituent of many minerals (UNEP 2013). Cr is emitted to the atmosphere via
natural sources such as windblown dust, forest fires, and anthropogenic sources such
as mining, smelting, refining, fossil fuel combustion, and waste incineration (ATSDR
2005, 2012). Chromium contents in moss samples varied from 1.47 to 262 mg kg
−1
(INAA Analysis), with an average concentration of 27 mg kg
−1 . It shows a high
variation (CV % = 168%) and high positive values of skeweness and kurtosis that
indicate high disparity of the concentration data with a tendency of skewed right.
High differences were observed among different areas (Fig. 5.1) that indicate the
effects of different factors. The spatial analysis plot of Cr (linear model) (Fig. 5.1)
shows a high increase from the south to the north direction of the country (Cr = 3.7
+ 0.928 × n, n represents the number of sampling site) that is characterized by a
high slope in the linear model (b = 0.928, very close to the maximum value of b =
1). This trend with very high slope in regression line, is dominately affected by the
significant Cr maximum concentration at the site 42 (Bulqiza area).
High Cr concentrations were found in St. 11, 13, 14, 24, 27, 41, 42, 43 and 47
positioned in the south, central part and in the North-East of the country. The highest
Cr content was found in St. 42, Bulqiza region that is the area of main Cr deposits
of Albania. High Cr contents in moss samples of St. 41, 43 and 47, respectively at
Librazhd, Burrel and Bujan, are strongly linked with geogenic factors of these areas
that are known for their chromite deposits and Cr mining industry. These findings
indicate the important role of soil dust fine mineral particles as the main source of Cr
in these areas. Moss samples at the areas with very high of certain trace elements in
45
40
35
30
25
20
15
10
5
1
250
200
150
100
50
0
MAPE
255.09
MAD
23.07
MSD
1609.73
Accuracy Measures
n
Cr
Actual
Fits
Variable
Spatial Analysis Plot for Cr
Linear Trend Model
Cr = 3.7 + 0.928×n
Fig. 5.1 Spatial analysis plot of Cr