Geochemical Characteristics of the Vertical Distribution of Heavy Metals in the Hummocky Peatlands of the Cryolithozone

Roman Vasilevich; Mariya Vasilevich; Evgeny Lodygin; Evgeny Abakumov

doi:10.3390/ijerph20053847

Geochemical Characteristics of the Vertical Distribution of Heavy Metals in the Hummocky Peatlands of the Cryolithozone

Int J Environ Res Public Health. 2023 Feb 21;20(5):3847. doi: 10.3390/ijerph20053847.

Authors

Roman Vasilevich¹, Mariya Vasilevich¹, Evgeny Lodygin¹, Evgeny Abakumov²

Affiliations

¹ Institute of Biology, Komi Science Center, Ural Branch, Russian Academy of Sciences, 167982 Syktyvkar, Russia.
² Department of Applied Ecology, Faculty of Biology, Saint Petersburg State University, 199178 St. Petersburg, Russia.

Abstract

One of the main reservoirs depositing various classes of pollutants in high latitude regions are wetland ecosystems. Climate warming trends result in the degradation of permafrost in cryolitic peatlands, which exposes the hydrological network to risks of heavy metal (HM) ingress and its subsequent migration to the Arctic Ocean basin. The objectives included: (1) carrying out a quantitative analysis of the content of HMs and As across the profile of Histosols in background and technogenic landscapes of the Subarctic region, (2) evaluating the contribution of the anthropogenic impact to the accumulation of trace elements in the seasonally thawed layer (STL) of peat deposits, (3) discovering the effect of biogeochemical barriers on the vertical distribution of HMs and As. The analyses of elements were conducted by atom emission spectroscopy with inductively coupled plasma, atomic absorption spectroscopy and scanning electron microscopy with an energy-dispersive X-ray detecting. The study focused on the characteristics of the layer-by-layer accumulation of HMs and As in hummocky peatlands of the extreme northern taiga. It revealed the upper level of microelement accumulation to be associated with the STL as a result of aerogenic pollution. Specifically composed spheroidal microparticles found in the upper layer of peat may serve as indicators of the area polluted by power plants. The accumulation of water-soluble forms of most of the pollutants studied on the upper boundary of the permafrost layer (PL) is explained by the high mobility of elements in an acidic environment. In the STL, humic acids act as a significant sorption geochemical barrier for elements with a high stability constant value. In the PL, the accumulation of pollutants is associated with their sorption on aluminum-iron complexes and interaction with the sulfide barrier. A significant contribution of biogenic element accumulation was shown by statistical analysis.

Keywords: biogeochemical barriers; ecotoxicants; histosols; peatlands; subarctic region; technogenesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ecosystem
Environmental Pollutants* / analysis
Iron / analysis
Metals, Heavy* / analysis
Soil / chemistry

Substances

Metals, Heavy
Soil
Iron
Environmental Pollutants

Grants and funding

The reported study by Lodygin E., Vasilevich R. and Vasilevich M. was funded by the Federal budget of Russia, within the framework of the research topics of the In-stitute of Biology (No. 122040600023-8 and 122040600026-9). The work of E. Abakumov (e.abakumov@spbu.ru) was supported by the St. Petersburg State University grant No. GZ_MDF_2023–1, ID: 101662710.