Application of contamination indexes on different farming soils

Background levels and baseline values of available heavy metals in Mediterranean greenhouse soils (Spain)

“…According to Andreu and Boluda (1995), Gimeno-García et al (1995 and Gil et al (2004Gil et al ( , 2010, the available fraction percentage (A) and Zn Equivalent Index (ZnEq) were calculated and applied to provide a basis to compare the potential heavy metal mobility and toxicity in soils in accordance with Expressions (1) and (2):…”

Concentrations of Available Heavy Metals in Mediterranean Agricultural Soils and their Relation with Some Soil Selected Properties: A Case Study in Typical Mediterranean Soils

“…The Zn Equivalent Indices (ZnEqT for total heavy metals and ZnEqB for available heavy metals) were used to compare the potential heavy metal toxicity in these soils [12,17,18,42]. They both were calculated as:…”

“…However, there is still very little direct measurement data or predictions of the available fraction of metals in soils. In Portugal and Spain for instance, there is hardly any information at all on available heavy metals in agricultural soils, and this lack of information is reflected in poorly informed legislation, which does not take soil characteristics into account [17,18]. The initial soil pH and the ability of plant roots to change the pH have been found to be the principal predictors of the exchange of heavy metals, and therefore of their bioavailability [19].…”

Multiscale analysis of heavy metal contents in Spanish agricultural topsoils

“…The contribution of metals from anthropogenic sources in soils can be higher than the contribution from natural ones (Liu et al, 2005). Irrespectively of the origin of the source, heavy metals can produce negative effects on the quality of agricultural products (Alegria et al, 1991;Boluda et al, 1993;Gimeno-Garcia et al, 1996;Andreu and Boluda, 1995;Baranowska et al, 2005).…”