Monitoring bioconcentration of potentially toxic trace elements in soils trophic chains

Abstract

Potentially toxic trace elements (PTEs) may be transferred to plants and consequently enter the food chain. Environmental monitoring of PTEs is important to control their concentrations in the environment and, particularly in farmland soils. The study aims at estimating the concentration of PTEs in the soil, its grass cover and collected soil invertebrates and consequently to investigate the transfer of pollutants in the soil-plant-fauna trophic chain. None of the PTEs was recorded in soil concentrations at levels exceeding the limits defined by the Regulation of the Minister of Environment. Mean concentrations of Zn, Pb, Cd, Ni, and Cu in soil were 55, 52, 44, 23, and 10 % of the permitted values, respectively. The concentrations of potentially toxic trace elements in soil samples were higher compared to their levels in grass, except for Cd which was the other way around. Higher concentration of Cd in grass than in soil may be attributable to direct deposition of metal particulates emitted from motor vehicles on grass, rather than soil along the road. As far as other metals (Pb, Ni, Cu, Zn) are concerned, concentration in soil was higher than in grass, however, lower than in the fauna. In the investigated meadow, both grass cover and the collected soil fauna accumulated cadmium in largest amounts and incorporated the studied metals in the following order:All considered elements showed greater concentrations (nearly tenfold higher for cadmium) in fauna than grasses.

The impact of increased flooding occurrence on the mobility of potentially toxic elements in floodplain soil – A review

“…Redox potential therefore not only affects the mobility of PTEs, but also their toxicity (Lee et al, 2005;Shahid et al, 2017). The consequences of PTEs contamination of soils are rarely observed with immediate effect, rather they tend to cause delayed adverse ecological changes, due to the fact that PTEs are persistent in the environment for long periods, non-biodegradable and can only be bio-transformed through complex physico-chemical and biological processes (Chrzan, 2016;Czech et al, 2014;Hooda, 2010). PTEs cause adverse ecological effects on plants and organisms such as impacting their activity, growth rate/yield, metabolism and reproduction, causing symptoms of physiological stress and potentially death.…”

“…As the PTEs are released into the aqueous phase and mobilised in the environment, they present a potential risk to soil organisms (Ehlers and Loibner, 2006;González-Alcaraz and van Gestel, 2015). Soil organisms uptake PTEs via ingestion of polluted soil, food or pore water and/or via dermal uptake or absorption of soil water, with the soil water being the more important of the two pathways (Chrzan, 2016;Hobbelen et al, 2006;Sivakumar and Subbhuraam, 2005). Vijver et al (2007) found that the frequency of flooding did not result in consistent changes in the internal PTEs concentrations of earthworms.…”

Background concentrations and quality reference values for some potentially toxic elements in soils of São Paulo State, Brazil

“…Environmental monitoring of PTE is important for controlling their concentrations in the environment, particularly in agricultural soils (Chrzan, 2016). The natural background concentrations of PTE in soils with no or minimal human influences, represent an important level used for establishing threshold values in order to differentiate contaminated from "clean" soils (Coppola et al, 2010).…”

Profile of Trace Elements in Selected Medicinal Plants Used for the Treatment of Diabetes in Eritrea

“…Clinical studies suggest that the body's balance of mineral trace elements is disrupted by diabetes and thus diabetic individuals are susceptible to trace element deficiency [ 8 ]. Even though trace elements are important for the normal functioning of the body, they can be harmful and toxic at high concentrations [ 9 ]. Therefore profiling the levels of these elements is mandatory in monitoring the safety of herbal preparations employed in the management of diabetes and other ailments.…”