Copper and cadmium content in Polish soil: Analysis of 25‐year monitoring study

Abstract

Metals can accumulate in agricultural soils, presenting a serious threat to human health; therefore, it is important to analyze the quality of these soils to avoid possible harm related to their contamination in the future. Despite the importance of monitoring arable soil quality, few studies have examined the current state of Cu and Cd soil contamination through analysis of historical data and temporal trends in heavy metal content. Therefore, this study was aimed at analyzing the spatial variability of Cu and Cd content (expressed by toxicity indices) and assessing the level of contamination of arable soils in Poland over the last 25 years (1995–2020). The average Cu content in soil throughout the duration of the study was ~10 mg/kg. The average Cd content increased from 0.7 mg/kg (in 1995) to 3.4 mg/kg (in 2020). The evaluation of Cu and Cd soil contamination showed that soils contaminated with Cd and Cu constituted 1.4% and 2.3% of the total monitoring points, respectively. The geoaccumulation index and pollution index ranged for Cu from −5.23 to 3.09 (mean: −2.50) and from 0.02 to 6.40 (mean: 0.20), and for Cd from −5.23 to 6.92 (mean: −1.67) and from 0.01 to 60.58 (mean: 0.44). The soil was practically uncontaminated with Cu and Cd in 98.77%/98.92% and 93.44%/97.92% of cases, respectively. On a national scale, the contents of Cu and Cd in soils depend on soil properties (pH, C, OM, ST, and CM) to a very small extent. An assessment of the spatial distribution of Cu and Cd concentrations in Polish arable soils indicated regional differences related to the degree of industrialization/urbanization. The obtained results show the impact of human activity on the level of heavy metals present in soils.

Geochemical Factors as a Tool for Distinguishing Geogenic from Anthropogenic Sources of Potentially Toxic Elements in the Soil

“…The geoaccumulation index (Igeo) is useful for assessing and analysing trace elements in soil as it intuitively reflects the impact of human activities on trace elements as well as the impact of trace elements on the environment [21,22]. The method was introduced by Muller [23] and is commonly used to quantify metal pollution in soils and aquatic sediments.…”

“…The method was introduced by Muller [23] and is commonly used to quantify metal pollution in soils and aquatic sediments. Wdowczyk et al [22] found increased Cd levels in areas where intensive mining as well as metallurgical and industrial activities were carried out. Their study also indicates the impact of human activities on heavy metal concentrations in soils.…”

Cadmium in Selected Organs of Game Animals from Areas with Different Degrees of Industrialisation and Its Intake by Human Consumers

“…In Poland, soil contamination is often observed in industrialised areas, in metal ore mining and processing areas, near metallurgical and smelting plants, and land used for transport and agriculture [6,7]. A Polish study by Wdowczyk et al [8] found the mean Cd concentration in soil to increase from 0.7 to 3.4 mg/kg between 1995 and 2020. It is also important to note that while Cd is immobilised in soils with neutral and alkaline pH, it changes to a mobile form as the pH decreases [9].…”