54
(Librazhd and Burrel areas). Other Pb anomalies though lower in concentration
levels were found in different parts of the country indicating the different sources of
Pb content in moss samples. The spatial analysis plot of the Pb normalized concentration data (Fig. 2.10b) looks likely uniform throughout the whole territory indicating low anthropogenic sources. The highest anthropogenic effects were found in St.
45 (Burrel) followed by St. 40 and 41 (Bilisht and Pogradec). Small Pb anomalies
were found in St. 23 and 24 (Berat and Kuçova). All these areas are known for their
ore deposits and mining activity. By comparing the spatial distribution of Pb concentration data and normalized concentration data, it is clearly showed that most of
the country is affected by natural emission sources of Pb mostly caused by soil dust
emission. The spatial analysis plot of Pb (linear model) shows more stable and
homogenous distribution of Pb throughout the country (Pb = 2.308 + 0.0335 × n; n
represents the number of sampling site) (Fig. 2.10) that is probably derived from
long-range transport of pollutants and local natural emission sources. The outlier
points with high Pb content are probably indicating the local anthropogenic inputs
of Pb. Differences observed on spatial distribution of Pb during two moss monitoring surveys probably are derived from the changes in the bioavailability of the elements caused by the climatic changes that favour dry deposition on 2010 moss
survey and wet deposition on 2010 (Lazo et al. 2019, Qarri et al. 2019).
Pearson correlation analysis showed very strong and significant correlation
between Pb concentration data and Pb normalized concentration (Pb(N) data
(r = 0.719, p = 0.000) probably indicating that the effect of anthropogenic sources
is stronger than the natural emission sources. Pb normalized concentration data
show moderate and significant correlations with Ni and Ni(N) data (r = 0.528 and
484, p < 0.001, respectively). The correlation of Pb vs. Pb(N) is verified by the linear regression analysis (Fig. 2.11).
2.3.2.6 Mercury
Mercury is a global pollutant that occurs in the environment in different forms such
as metallic, inorganic and organic mercury. It is a metal naturally occurring in
earth’s crust and is widely used in different processes and man-made products
(ATSDR 1999). Hg ranged from 0.04 to 0.213 mg kg
−1
with an average content of
0.059 mg kg
−1
. The concentration data of Hg show a moderate variation
(CV% = 68%) followed by relatively high positive values of skewness and kurtosis
(1.86 and 4.2, respectively). Relatively high Hg content was found in the southern
coastal area from Borsh to Ilias (St. 3 to St. 5), in the S-E (St. 35, 37–39) in the
border line between Albania and Greece and in the north part of the country (St. 49).
The spatial analysis plot of Hg normalized concentration data that reflect the anthropogenic Hg contribution showed a different view regarding the distribution of the
Hg(N) data. The first anomaly in the S-W is still evident (St.1 to St. 5). The second
area with relatively high Hg(N) values was found in the S-E (St. 38 to St. 42), and
the next one zone is recorded in the north (St. 9, 51, 52 and 54).
S. Allajbeu et al.
(Librazhd and Burrel areas). Other Pb anomalies though lower in concentration
levels were found in different parts of the country indicating the different sources of
Pb content in moss samples. The spatial analysis plot of the Pb normalized concentration data (Fig. 2.10b) looks likely uniform throughout the whole territory indicating low anthropogenic sources. The highest anthropogenic effects were found in St.
45 (Burrel) followed by St. 40 and 41 (Bilisht and Pogradec). Small Pb anomalies
were found in St. 23 and 24 (Berat and Kuçova). All these areas are known for their
ore deposits and mining activity. By comparing the spatial distribution of Pb concentration data and normalized concentration data, it is clearly showed that most of
the country is affected by natural emission sources of Pb mostly caused by soil dust
emission. The spatial analysis plot of Pb (linear model) shows more stable and
homogenous distribution of Pb throughout the country (Pb = 2.308 + 0.0335 × n; n
represents the number of sampling site) (Fig. 2.10) that is probably derived from
long-range transport of pollutants and local natural emission sources. The outlier
points with high Pb content are probably indicating the local anthropogenic inputs
of Pb. Differences observed on spatial distribution of Pb during two moss monitoring surveys probably are derived from the changes in the bioavailability of the elements caused by the climatic changes that favour dry deposition on 2010 moss
survey and wet deposition on 2010 (Lazo et al. 2019, Qarri et al. 2019).
Pearson correlation analysis showed very strong and significant correlation
between Pb concentration data and Pb normalized concentration (Pb(N) data
(r = 0.719, p = 0.000) probably indicating that the effect of anthropogenic sources
is stronger than the natural emission sources. Pb normalized concentration data
show moderate and significant correlations with Ni and Ni(N) data (r = 0.528 and
484, p < 0.001, respectively). The correlation of Pb vs. Pb(N) is verified by the linear regression analysis (Fig. 2.11).
2.3.2.6 Mercury
Mercury is a global pollutant that occurs in the environment in different forms such
as metallic, inorganic and organic mercury. It is a metal naturally occurring in
earth’s crust and is widely used in different processes and man-made products
(ATSDR 1999). Hg ranged from 0.04 to 0.213 mg kg
−1
with an average content of
0.059 mg kg
−1
. The concentration data of Hg show a moderate variation
(CV% = 68%) followed by relatively high positive values of skewness and kurtosis
(1.86 and 4.2, respectively). Relatively high Hg content was found in the southern
coastal area from Borsh to Ilias (St. 3 to St. 5), in the S-E (St. 35, 37–39) in the
border line between Albania and Greece and in the north part of the country (St. 49).
The spatial analysis plot of Hg normalized concentration data that reflect the anthropogenic Hg contribution showed a different view regarding the distribution of the
Hg(N) data. The first anomaly in the S-W is still evident (St.1 to St. 5). The second
area with relatively high Hg(N) values was found in the S-E (St. 38 to St. 42), and
the next one zone is recorded in the north (St. 9, 51, 52 and 54).
S. Allajbeu et al.