Pesticide Residues in Vegetation - Pesticides: Evaluation of Environmental Pollution - page 312

was conducted in a contaminated area. In the study of aquatic plants (species named above
for DDT), the results ranged from 0.005 mg/kg in E. flexuosa in Spain to 97.3 mg/kg in C.
linum in the same place. Finally, HCH concentrations obtained in different tree species of
pines and mangoes ranged between 0.9 mg/kg of β-HCH in Pic. abies (spruce) in Croatia
and 12.0 mg/kg of γ-HCH in T. platyphyllos in the same country (Krauthacker et al. 2001).
HCB has been detected, especially in the species of Pinus spp. and lichens and mosses,
since, as noted above, most of these studies have been conducted in the Northern
Hemisphere. Some studies in mangoes ( M. indica ) and other species, such as L. decidua ,
P. nigra , T. platyphyllos , Pic. abies , Th. occidentalis , Ab. alba , and grasses have also been con-
ducted. The maximum value of HCB was found in pines in Milan (Italy) (Calamari et al.
1994).
The aldrin, dieldrin, endrin, endrin aldehyde, heptachlor, and endosulfan pesticides
were studied in the following aquatic species: R. cirrhosa , Cym. nodosa , Ca. prolifera , E. flex-
uosa , C. linum , La. obtus , H. cervicornis , and Ac. calyculus , in Spain. The maximum concen-
tration value was obtained for endrin aldehyde in C. linum . Endosulfan in pines, spruces,
and grasses in the mountainous regions of Alberta (Canada) and the Mt Qomolangma
(Himalaya) was also studied.
However, the PCP compound has only been compiled in a study on P. sylvestris in seven
European countries (Sweden, Norway, Denmark, Germany, France, Switzerland, and
Poland).
10.3.4 Distribution with Elevation
The relationship between the presence of POPs and the altitude has been extensively stud-
ied worldwide in high mountain regions (e.g., Davidson et al. 2003; Villa et al. 2003). These
studies have established gradients of correlation between both the parameters for differ-
ent locations. According to the studies on grasses, there is a positive correlation between
the presence of HCH and HCB and elevation, while in the case of o,p'-DDT, p,p'-DDT, and
aldrin, there is an inverse correlation between the concentrations of these compounds and
elevation (Wang et al. 2007). In general, it can be said that high elevation areas may act as
condensers of POPs (Wang et al. 2007). This is due mainly to low temperatures in these
areas.
10.4 Conclusions
The number of studies on the pesticides in natural vegetation are scarce, compared with
those on the pesticides in other environmental compartments such as air, soil, or water
(Barber et al. 2005). Most studies have been conducted in Europe, considering only organo-
chlorine pesticides, mainly DDT and lindane, so the discussed results can be very slant.
However, vegetation is at the base of the food chain and plays a key role in the nutrient
cycles in nature, so it is important to include vegetation in monitoring programs of envi-
ronmental pollution.
The concentrations of pesticides in different plant species depend largely on the chemi-
cal properties of the compounds and the meteorological conditions in the areas, although
also on the characteristics of each plant species. Therefore, the choice of the species to
be used to monitor pollution by POPs is of great importance. In general, there should be