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Page 12 of 21 Artyukhov et al. Carbon Footprints 2026, 5, 8

represent the greatest potential for positive feedback to climate change .
[58]

Ecotoxicological state of soils and radial differentiation of metals
The studied area is characterized by high diversity and patchiness of the soil cover, while the level of heavy
metal contamination in the soils is generally low. The highest concentrations of heavy metals were observed
in soil samples with high SOC content and high clay and silt fractions. Soils of the southern hypoarctic
tundras of the Yamal Peninsula contained Pb - 14 mg/kg, Co - 9 mg/kg, and V - 42 mg/kg. Soils of the
mountain tundras of the Polar Urals contained Pb - 11 mg/kg and V - 87 mg/kg. Soils of the forest-tundra of
the Lower Ob region contained Pb - 27 mg/kg, Co - 18 mg/kg, and V - 129 mg/kg, which is attributed to
their high sorption capacity [45,63] . The level of soil contamination by heavy metals is influenced both by the
functional load on the area and the physicochemical characteristics of soils . Soil contamination with heavy
[60]
metals is associated with areas of geological exploration, hydrocarbon production, roads, and settlements.
Soils sampled in areas remote from major transport highways exhibit low (acceptable) contamination levels
(Zc < 16), consistent with earlier studies .
[63]
Based on the total heavy metal content in the soils, the values of Zc were calculated [Figure 5]. Analysis of the
obtained data, considering territorial affiliation, revealed the following: Out of 16 soil samples collected on
the Yamal Peninsula (Ya_P1, Ya_P2), 9 were characterized by low (acceptable) total contamination levels
(Zc < 16), and 7 by moderate (moderately hazardous) levels (16 < Zc < 32), which may be attributed to the
proximity of the winter ice road “Payuta-Novy Port”. In the Polar Urals, most of the studied samples (RI_C2,
RI_C3, RI_C5, RI_C6) exhibited acceptable total contamination levels, with only 1 out of 18 samples
showing a moderate (moderately hazardous) level (16 < Zc < 32). Near populated areas such as the cities of
Salekhard, Labytnangi, and the settlement of Gornoknyazevsk, the highest number of soil samples (Sal_C1,
Gk_C7, Lb_C8) demonstrated moderate (moderately hazardous) or high (hazardous) levels of total soil
pollution. Specifically, 4 out of 14 samples were characterized by moderate levels, 2 samples by high levels
(32 < Zc < 128), and 8 samples by low (acceptable) levels (Zc < 16).

It was found that the majority (32 out of 47) of soil samples were characterized by a low (acceptable) level of
total contamination (Zc < 16), 13 samples by a moderate (moderately hazardous) level (16 < Zc < 32), and
only 2 by a high (hazardous) level (32 < Zc < 128). The priority pollutants were lead (Pb), vanadium (V), and
cobalt (Co). Elevated concentrations of lead and vanadium indicate a significant contribution of vehicle
emissions to heavy metal contamination of the soil cover. The spatial distribution of soils contaminated with
lead and vanadium correlates with the location of roads , confirming the dominant role of vehicle
[64]
emissions in the anthropogenic load on the environment of YaNAO and the ecotoxicological state of soils in
the region [65,66] .

The application of the coefficient of radial differentiation (R) enabled a quantitative assessment of the
influence of pedogenesis on the redistribution of individual chemical elements concentrations throughout
the soil profile relative to the parent material. Values of the radial differentiation coefficient of chemical
element concentrations in the soils of Yamal, Polar Urals and Lower Ob region exhibit distinct profile
distribution patterns [Figure 6].

In Albic Podzol (Sal_C1), an accumulation of Pb, Zn, and Co was observed in the upper horizons, while the
radial differentiation of other elements was insignificant. In Cryic Histosol (Gk_C7), V and Ni were leached
into lower horizons, whereas Pb and Zn accumulated in the upper horizons. In Histic Cryosol, Cr
accumulated in the upper horizon, while Ni, Co, and MnO leached into lower horizons. In Skeletic Cryosol
at one site (RI_C5), Ni, Co, and MnO were leached and accumulated in the lower horizons, while Sr, As, and
Zn accumulated in the upper horizons. At the second site (RI_C6), Pb accumulated throughout the soil