Ecotoxicity of Cr, Cd, and Pb on Two Mediterranean Soils

Abstract

Three potentially toxic elements [chromium (Cr), lead (Pb), and cadmium (Cd)] were tested to assess their effects on two soils of different properties and origin. The soils were a granitic soil (Haplic Arenosol), which meets the requirements of OECD ecotoxicity testing, and a calcareous soil (Calcaric Regosol) with properties often found in the Mediterranean areas. The metal concentrations used ranged from 0.001 to 5,000 mg kg(-1) soil. The effects on soil microbial activity and community composition (respirometry and polymerase chain reaction-denaturing gradient gel electrophoresis analysis), as well as the effects on plant germination and elongation (Lactuca sativa), were assessed. The toxicity of the soil water extracts was also evaluated by the growth inhibition of algal populations (Pseudokirschneriella subcapitata). Cr showed the highest level of toxicity to soil organisms in the assays performed because this element remains in soil as anionic form and is less retained by the soil solid matrix than Cd and Pb. The lowest observed-adverse effect level for Cr ranged from approximately 0.1 mg kg(-1) [substrate induced respiration (SIR) test for the granitic soil] to 10 mg kg(-1) (basal respiration and SIR tests for the calcareous soil). For Pb (SIR) and Cd (SIR and alga tests), these levels were approximately 100 mg kg(-1). Germination and algal tests showed higher sensitivity in Regosol soil than in Arenosol soil for Cr due to differences in the bioavailability between the soils. In the cases or areas where alkaline soils are abundant, these should also be considered in laboratory ecotoxicity testing to avoid underestimation of ecotoxicological risks.

Speciation Distribution of Heavy Metals in Uranium Mining Impacted Soils and Impact on Bacterial Community Revealed by High-Throughput Sequencing

“…Therefore, microbial-induced conversion of Cr (VI) to Cr (III) leads to a reduction in toxicity, which may be a result of the precipitation of various Cr (III) chemical forms. Moreover, a toxicity has been observed even in soils containing very low contents of Cr (VI) (<1 mg kg –1 ) (Martí et al, 2013). Min et al (2017) reported that total Cr content affiliated with Cr (VI) was the major factor for the difference of soil bacterial communities.…”

Assessment of Soil Contamination with Potentially Toxic Elements and Soil Ecotoxicity of Botanical Garden in Brno, Czech Republic: Are Urban Botanical Gardens More Polluted Than Urban Parks?

“…Metal bioavailability is a key factor in determining the metal’s toxicity and uptake by organisms [ 54 ] and is significantly affected by soil properties such as pH [ 48 ]. Such alkaline soil as in this case limits the presence of fractions of water-soluble soil contaminants in aqueous soil extracts [ 55 ]. Therefore, the overall PTEs bioavailability could be reduced, and the results showed decreased toxicity effect on the tested organisms.…”

Вплив екскреторної функції ссавців на активність аспартатамінотрансферази в листках Glechoma hederacea в умовах забруднення кадмієм

“…вивчено транспорт есенціальних металів (Fe, Zn, Mn і Cu) і транспорт, толерантність, вакуолярну послідовність та рівень транскрипційних реакцій за умов дії неесенціальних металів (Cd, Pb, Cr, Hg і As), їх токсичність на рослинний гомеостаз (Mendoza-Cózatl et al, 2011;Song et аl., 2010;Takamatsu et аl., 2010). Визначено вплив Cr, Cd та Pb на середземноморські ґрунти (Martí et al, 2013) через біодоступність Cd, Pb та Zn та через атмосферні емісії Cd та Pb (Roussel et al, 2010), визначено рослинний метаболізм під впливом Cd, Co, Mn, Cr (Hameed et al, 2011;Hasan et al, 2011;Ruscitti et al, 2011;Vestena et al, 2011;Becerril et al, 2013;Lefcort et al, 2013;Millaleo et al, 2013).…”