Arsenic drives soil health risks in Armenia’s Shirak region

Soils across the Shirak region of northwestern Armenia carry arsenic at concentrations well above both global reference levels and national safety thresholds, according to a new geospatial assessment published in Environmental Geochemistry and Health. The study, described by its authors as the first baseline geochemical characterization of soils in this agricultural region, maps the distribution of seventeen soil parameters, identifies which elements travel together in the landscape, and estimates the human health risks associated with swallowing contaminated soil particles.

The research team, led by scientists affiliated with Armenian institutions together with an Italian collaborator, analyzed arsenic, manganese, titanium, calcium, potassium, barium, chromium, vanadium, cobalt, zirconium, strontium, rubidium, zinc, copper, lead and soil pH. Their central finding is a pronounced enrichment of several elements relative to the Upper Continental Crust, the standard reference composition used to judge whether soil chemistry is natural or disturbed. Mean arsenic concentrations of 15.1 milligrams per kilogram exceeded the crustal reference by a factor of 3.15, the largest relative enrichment in the dataset. Manganese, at a mean of 1104 milligrams per kilogram, ran 1.65 times above the reference value, titanium 1.33 times, copper 1.35 times and chromium 1.20 times.

Enrichment alone does not establish pollution, because some regions are naturally endowed with elevated element levels. To separate geology from contamination, the researchers combined correlation analysis, k-means clustering and principal component analysis biplots, statistical tools that reveal which elements behave as coherent groups across the mapped area. The analysis resolved two distinct geochemical associations. The first groups iron, cobalt, titanium, vanadium, zinc, zirconium, rubidium, lead and manganese, an assemblage the authors interpret as typical of volcanic rocks, pointing to predominantly natural origins for these elements.

The second association links calcium, strontium, barium and potassium, and its footprint coincides with areas where Kastanozems and Chernozems, soils characteristic of dry grassland climates, have formed. These soils tend to accumulate secondary carbonates, and the association is strongly tied to soil pH, suggesting that the regional pattern of these elements reflects soil-forming processes rather than anthropogenic inputs.

Against regulatory benchmarks, however, two elements stood out. Mean concentrations of arsenic and chromium exceeded the Maximum acceptable concentration by factors of 1.51 and 1.15 respectively, indicating that average soil levels in the region surpass the thresholds used to flag potential concern. Arsenic is the more troubling of the pair: it is a recognized carcinogen, and its enrichment factor of more than three relative to the continental crust, combined with its exceedance of the acceptable concentration, makes it the element of greatest interest for follow-up work.

The health risk assessment focused on the ingestion pathway, the route by which people inadvertently swallow soil and dust. The results showed that across the entire region, both non-carcinogenic and carcinogenic risk levels were observed for children. Among the elements assessed, arsenic contributed the most to the overall health risk estimates, consistent with its high measured concentrations and toxicological potency.

The authors emphasize that the study provides the first baseline geochemical characterization of Shirak region soils. Baselines of this kind matter because they establish the natural background against which future changes, whether from agricultural intensification, industrial development or other land-use shifts, can be measured.

Several caveats follow from the scope of the published findings. The reported health risk figures are model-based estimates derived from measured concentrations and standard exposure assumptions, not direct measurements of arsenic or chromium in residents themselves. The abstract reports regional mean values and does not detail the spatial extent of the highest concentrations or the specific contributions of individual districts. The study also addresses the ingestion pathway specifically; inhalation and dermal contact, the other standard exposure routes in health risk frameworks, are not covered in the reported results.

For an agricultural region whose soils support crop production, the combination of arsenic levels more than three times the continental crust reference and exceedance of the acceptable concentration carries practical weight. The authors position the work as a foundation for soil management in Shirak, and the identification of two geochemically distinct element groups gives local authorities a framework for distinguishing naturally elevated areas from those where monitoring for anthropogenic influence may be warranted. As the first systematic geochemical map of the region’s soils, the study fills a documented gap and sets the reference point against which any future assessment of soil quality in Shirak will be judged.

Subject of Research: Geospatial assessment of potentially toxic elements and associated human health risks in agricultural soils of the Shirak region, Armenia

Article Title: Geospatial assessment of potentially toxic elements in soil: distribution, geochemical associations and health risks in an agricultural region (Shirak, Armenia)

Article References: Tepanosyan, G., Poghosyan, Z., Gevorgyan, A., Saribekyan, A., Yenokyan, T., Ricca, N., & Guagliardi, I. (2026). Geospatial assessment of potentially toxic elements in soil: distribution, geochemical associations and health risks in an agricultural region (Shirak, Armenia). Environmental Geochemistry and Health, 48(16), Article 661. https://doi.org/10.1007/s10653-026-03565-2

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03565-2

Keywords: soil geochemistry, arsenic, chromium, potentially toxic elements, Shirak Armenia, human health risk assessment, Upper Continental Crust, geochemical associations, Kastanozems, Chernozems, soil ingestion pathway, Environmental Geochemistry and Health