Pesticide Residues in Vegetation - Pesticides: Evaluation of Environmental Pollution - page 308

In the studies carried out on other species, high concentrations have been obtained, for
example, 97.3 μg/kg of HCH was found in Chaetomorpha linum in Murcia (Spain). In addi-
tion, especially high concentrations of HCH, with values above 20 mg/kg for the congeners
α- and β-HCH were obtained in a study performed on the species Cytisus striatus , Avena
sativa , Vicia sativa , Solanum nigra , and Chenopodium vulgare in a polluted area in Galicia
(Spain) (Barriada-Pereira et al. 2005).
The HCB pesticide in plant samples in a total of 33 countries, most of them in the Northern
Hemisphere, has been studied. By considering the average values, in 51% of the samples
the concentrations were below 0.5 μg/kg, and in 12% the concentrations were between 0.5
and 1 μg/kg. Figure 10.3 shows the average concentration of HCB in vegetation samples
obtained from different countries. The highest concentrations are found in the Northern
Hemisphere, principally Iceland, Norway, Italy, and Czech Republic; the maximum value
of concentration, 4.8 μg/kg, was detected in pines in Estonia and Germany (Hellström
et al. 2004). In the Southern Hemisphere, only the results obtained in Antarctica and Kenya
stand out.
In general, higher concentrations were found in the Northern Hemisphere because most
part of the emissions took place there. Moreover, the values are very homogeneous within
the countries because the use of HCB was banned in most of them and, therefore, the emis-
sion sources have been reduced.
These results agree with the data reported by Barber et al. (2005) about the concentra-
tion of this pollutant in air on a global scale. Furthermore, as in the case of HCH, HCB is
accumulated in cold places and high mountain areas.
< 0.1-0.5 µ g/kg
0.6-1.0 µ g/kg
1.1-10.0 µ g/kg
> 10.1 µ g/kg
FIGURE 10.3
Distribution of HCB (mean concentrations) in Pinus spp. (triangle), Magnifera indica (circle) and lichen/moss
(square) around the world. The size of the symbol indicates different mean concentration of HCB (see legend).