Toxic Effects of Thallium on Biological Indicators of Haplic Chernozem Health: A Case Study

Abstract

Thallium (Tl) was introduced into Haplic Chernozem in the amounts of 3, 30, and 300 mg/kg, and biological indicators were observed at 10, 30, and 90 days after incubation in the laboratory experiment. An increase in biological activities; i.e., the total number of bacteria, Azotobacter spp. abundance, enzymes (catalase, dehydrogenases), and phytotoxic indicators (germination rate of radish) after 30 days of Tl exposure were noted. The total number of bacteria and Azotobacter spp. abundance, enzyme activity, and phytotoxicity were more sensitive (16–76%) and informative (12–65%) indicators compared to the control, respectively. Integral biological indicators of soil state (IIBS) noted at 10, 30, and 90 days decreased at a dose of 30 and 300 mg/kg by 13–43% in relation to the control. An increase in Tl concentration and duration of exposure (up to 90 days) inhibited biological properties and caused ecotoxicological effects, respectively. We concluded that the use of individual indicators served as an indicator of the state of the soil.

Assessment of the Ecotoxicity of Pollution by Potentially Toxic Elements by Biological Indicators of Haplic Chernozem of Southern Russia (Rostov region)

“…The ecotoxicity of pollutants is manifested earlier than the three backgrounds (Kolesnikov et al, 2008a , 2009 , 2011 , 2014 , 2019 , 2020 , 2021 ; Popovich & Kolesnikov 2005 ). This applies to all studied elements.…”

“…Moreover, the study was conducted on Haplic Chernozem that is characterized by high buffer capacity with respect to chemical pollution. In soils with a lighter granulometric composition, less organic matter, and more acidic, the ecotoxicity of most pollutants will be even higher (Kolesnikov et al, 2020 , 2021 ; Guney et al, 2020 ; Minnikova et al, 2017 ). According to the degree of inhibition of biological activity in Haplic Chernozem, the studied metals formed the following series: Cd > Pb > Zn > Cu (Gromakova et al, 2017 ).…”

“…The ecotoxicity of such elements as Te, Se, Ag, Bi, Ge, and Tl is currently underestimated (Vodyanickii, 2012 ; Kolesnikov et al, 2020 , 2021 ). This is since their pollution is much less common than, for example, Hg, Cd, Pb, Cu, Zn, Cr, and Ni (Kabata-Pendias 2010 ).…”

“…The background content of thallium in soils is from 0.3 mg/kg (soils in China and France) to 2.8 mg/kg (geochemical anomaly in the south of Western Siberia) (Il’in & Konarbaeva, 2000 ; LaCoste et al 1999 ; Huang et al, 2016 ). Thallium influences the indices of plant seed germination, chlorophyll content, and enzymatic activity of soils (Pavlickova et al 2005 , 2006 ; Ferronato et al 2016 ; Guo et al 2018 ; Kolesnikov et al, 2021 ; Luo et al 2020 ). Thallium has a toxic effect on the soil and has a high accumulation rate in plants (Baceva et al, 2014 ; Sabermahani et al, 2016 ; Sizmur et al, 2016 ).…”

Estimation of the Enzymatic Activity of Haplic Chernozem under Contamination with Oxides and Nitrates of Ag, Bi, Te and Tl

“…Activity of oxidoreductases is an informative and sensitive indicator for soil contamination with heavy metals, petroleum hydrocarbons, and other xenobiotics [4,[55][56][57][58][59]. Activity of catalase in haplic chernozem when contaminated with oxides and nitrates of Ag, Bi, Tl, and Te is shown in Figure 2.…”