**5. Conclusion**

**Needle age Pb Cu Mn Zn Cd**

Current year 2.7 15.7 459 36.8 0.49 Ranges ICP forests 3.94 2.28–7.7 172.05–912 32–77.5 0.05–0.45 1 year 4.9 22.1 1466 49.6 0.54 Ranges ICP forests 0.14–5.59 1.96–6.88 222.05–1331.95 31.5–96 0.06–0.50

**Table 6.** Content of heavy metals in *Pinus sylvestris* needles from the area of Central Balkan National Park.

(3.1 mg kg−1), *Rubus idaeus* (2.9 mg kg−1), *Fragaria vesca* (1.5 mg kg−1), etc. [83].

and cadmium were relatively low.

150 Soil Contamination - Current Consequences and Further Solutions

for the area soil units (see **Table 7**).

soils [22].

Repeatedly increased copper content was determined in comparison with the established variation limits of these elements within the ICP Forests [41]. The exceedances of manganese

*Bulgarka Nature Park* is adjacent to the Central Balkan National Park. The park is located on the northern slopes of the central part of the Balkan range, occupying a total area of 21,772.163 ha. Environmental pollution risk in landscapes formed by alpine pastures, due to the soil enrich‐ ment with heavy metals, was determined on the park territory [79]. The maximum measured values of lead in soils reached 497 mg kg−1 and of arsenic—112 mg kg−1. These values were determined at the pasture of the Malusha locality. The following herbaceous plants were identified as strongly lead‐accumulating plants: *Holcus lanatus* (29.29 mg kg−1), *Thymus sp.* (42.32 mg kg−1), *Viola tricolor* (9.81 mg kg−1), etc. Arsenic‐accumulating plants are *Viola dacica*

The studies of heavy metal content in soils and plants of *Pirin National Park* are also very limited. The park was created in 1962 in order to preserve the natural character of the ecosystems and landscapes along with their plant and animal communities and habitats. The park territory, occupying 40,356.0 ha, has not been differentiated into appropriate landscape units yet. In order to study the soil pollution in 2015, the authors carried out a research on representative

**Soil unit Horizon Depth pH Pb Cu Mn Zn Cd**

Umbrisols A turf 0–8 5.7 58 16 549 82 1.35

Cambisols A0 3–0 5.4 26 7 336 47 1.65

Rendzic Leptosols A0 5–0 5.8 27 10 63 68 1.55

Only cadmium content can be assessed as excessive in accordance with the criteria on forest

**Table 7.** Heavy metal content in soils from the territory of the Pirin National Park.

**cm (H2O) mg kg−1**

A 8–60 6.5 55 14 519 67 1.50

A 0–33 5.0 41 12 252 56 0.90 B 33–75 6.2 32 13 204 55 1.15

A 0–33 7.1 52 11 110 68 2.45

**μg g−1**

The content of Pb, Cu and Zn in *Cambisols* and *Luvisols* from the regions of the western Balkan Mountains, Sredna Gora, Rhodope Mountains and Strandzha, remained stable during the period 1986–2015. Soils were not affected by acidic atmospheric depositions. The high heavy metal content in litter should be evaluated in relation to the soil pH. When evaluating the pollution of soils with heavy metals, it is necessary to take into consideration the maximum coefficients of their natural accumulation in the surface soil layers. Higher values of these coefficients should be achieved in order to determine pollution. It is necessary to expand the studies of heavy metal content in soils in national and nature parks. Sometimes, environmental risks can occur due to natural enrichment of soils with certain toxic elements. It is recom‐ mended to perform soil mapping and, if necessary, to restrict harvesting of medicinal plants and pasture in particular areas.
