Assessment of the pollution and ecological risk of lead and cadmium in soils

Abstract

The aim of the study was to assess the content, distribution, soil binding capacity, and ecological risk of cadmium and lead in the soils of Malopolska (South Poland). The investigation of 320 soil samples from differently used land (grassland, arable land, forest, wasteland) revealed a very high variation in the metal content in the soils. The pollution of soils with cadmium and lead is moderate. Generally, a point source of lead and cadmium pollution was noted in the study area. The highest content of cadmium and lead was found in the northwestern part of the area-the industrial zones (mining and metallurgical activity). These findings are confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. Among the different types of land use, forest soils had by far the highest mean content of bioavailable forms of both metals. The results showed a higher soil binding capacity for lead than for cadmium. However, for both metals, extremely high (class 5) accumulation capacities were dominant. Based on the results, the investigated soils had a low (Pb) and moderate (Cd) ecological risk on living components. Soil properties, such as organic C, pH, sand, silt, and clay content, correlated with the content of total and bioavailable forms of metals in the soils. The correlations, despite being statistically significant, were characterized by very low values of correlation coefficient (r = 0.12-0.20, at p ≤ 0.05). Therefore, the obtained data do not allow to define any conclusions as to the relationships between these soil properties. However, it must be highlighted that there was a very strong positive correlation between the total content of cadmium and lead and their bioavailable forms in the soils.

Geochemical Fractions of the Agricultural Soils of Southern Poland and the Assessment of the Potentially Harmful Element Mobility

“…As described previously [17] in southern Poland, where investigations were conducted, soils are generally classified as cambisols, podzols, and luvisols according to the World Reference Base for Soil Resources (IUSS Working Group 2015). The measured pH values classified the investigated agricultural soil samples as neutral in the Opolskie (pH H2O range: 6.8-7.2, mean: 7.0) andŚląskie (pH H2O range: 6.8-8.3, mean: 7.0) and slightly acidic in the Małopolskie (pH H2O range: 4.8-7.9, mean: 6.50),Świętokrzyskie (pH H2O range: 5.4-7.2, mean: 6.4), and Podkarpackie (pH Our tests of the pseudototal PHE contents in agricultural soil samples confirmed the results of the research conducted previously in the Regions of SE Poland: inŚląskie [28,[50][51][52][53], of S Poland: in Małopolskie [33,[54][55][56][57][58], and of SE Poland: in Podkarpackie [59] and inŚwiętokrzyskie [60]. Our results were also comparable to those obtained within the frame of the National Environmental…”

“…Actually available PHE contents in pore water were extracted with 20 cm 3 of 0.01 mol/dm 3 CaCl 2 and potential soluble total PHE concentration in pore water were extracted with 0.05 mol/dm 3 Na 2 EDTA from 2 g of each soil sample, followed by shaking for 2 h [27,32,33]. After extraction samples were centrifuged at 3000 rpm for 10 min, and supernatants were separated from precipitate through a filter.…”

The contents of the potentially harmful elements in the arable soils of southern Poland, with the assessment of ecological and health risks: a case study

“…The bioavailable forms of PHEs were extracted, 2 g of each soil sample, with 20 cm 3 of 0.01 mol CaCl 2 / dm 3 (Rauret 1998;Pueyo et al 2004;Wieczorek et al 2018) and shaken for 2 h. After extraction, the samples were centrifuged at 3000 rpm for 10 min. The supernatants were separated from the precipitates through a filter.…”

The lead toxicity and pollution with this element in Poland

“…The metal is also capable of displacing essential microelements from metalloenzymes. It can also impede the biosynthesis of heme and cause disturbances in microelement (Fe, Cu, Zn Se and Ca) metabolism [2,[9][10][11][12]. Calcium and phosphorus administered singly reduce Pb absorption from the gastrointestinal tract by 1.3 and 1.2 times, albeit less than when these nutrients were given jointly (a 6-fold reduction).…”

“…Mining operations began as early as the 12th century and these regions were leading producers of Pb in the Middle Ages. In prior centuries, Pb was commonly used for covering roofs, window frames, pipes, tableware, jewelry, weights, making glass, shooting balls, printing fonts and for the toy industry for the production of lead soldiers [1, 12,28].…”