Publications by authors named "Karel Nemecek"

The present study investigated the distribution of elements and potentially toxic elements (PTEs) in soil profiles in the southeastern region of Nigeria, where unrefined and primitive mining practices are common. Soil samples were collected from mine and non-mine sites in Ameka and Nkalagu and analyzed for total elemental concentration using portable X-ray fluorescence (pXRF). The results showed that the Ameka mine-affected soils were heavily polluted, while the Ameka non-mine-affected soils were moderately polluted.

View Article and Find Full Text PDF

Increasing concentrations of potentially toxic elements (PTE) in agricultural soils remain a major source of public concern. Monitoring PTEs in an agricultural field with no history of contaminants necessitate adequate analysis utilizing a robust model to accurately uncover hidden PTEs. Detecting and mapping the distribution of soil properties using portable X-ray fluorescence (pXRF) and proximal sensing techniques is not only rapid, but also relatively inexpensive.

View Article and Find Full Text PDF
Article Synopsis
  • * The study used portable X-ray fluorescence to analyze 49 soil samples for total PTE concentrations and applied statistical methods to find correlations between PTEs and potential normalizers like Al, Fe, and Rb.
  • * Results showed that Rubidium (Rb) is the best normalizer and the World Average Value (WAV) is the most suitable GBL, aiding future soil quality evaluations in agricultural settings.
View Article and Find Full Text PDF
Article Synopsis
  • * The study explores the effectiveness of using combined visible-near infrared (vis-NIR) and X-ray fluorescence (XRF) spectroscopy, along with feature selection methods, to assess soil PTEs in a polluted region of the Czech Republic.
  • * Results indicate that XRF alone, especially when using genetic algorithm-selected data, outperforms vis-NIR and their fusion for predicting PTEs, with the best models improving accuracy in detecting arsenic and lead contamination.
View Article and Find Full Text PDF

Environmental pollution by potentially toxic element (PTE) and the associated health risks in humans are increasingly becoming a global challenge. The current study is an in-depth assessment of PTEs including the often studied lead (Pb), manganese (Mn), zinc (Zn), arsenic (As) and the less-studied titanium (Ti), rubidium (Rb), strontium (Sr), zirconium (Zr), barium (Ba) and thorium (Th) in highly polluted floodplain topsoil samples from the Litavka River, Czech Republic. Soil chemical properties including carbon (C) and reaction (pH_HO) together with iron (Fe) were assessed in the same soils.

View Article and Find Full Text PDF

Composition of soil vegetation cover and land management directly influences the cycling of chemical elements and is a key factor for soil biogeochemistry and also Al behaviour. Moreover, Al is an important factor limiting the growth of cultural plants. Our results are based on long-term observations of soils translocated from selected small areas of eight 1 ha plots of different land-use gradient, with identical geological, climatic and geographical conditions, located in the North of Congo Basin (near Mbalmayo, Cameroon).

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigated how aluminum (Al) behaves in soils beneath beech forests with different types of parent rock, while also examining how herbaceous vegetation affects this behavior.
  • - Researchers hypothesized that the presence of vegetation significantly influences the soil's content of elements like aluminum, and low molecular mass organic acids (LMMOA) indicate the decomposition of soil organic matter and litter turnover.
  • - Findings showed that areas with less herbaceous vegetation had lower pH and nutrient levels, higher soil organic matter, and larger aluminum pools, indicating that LMMOA and vegetation cover are crucial for understanding the aluminum soil cycle.
View Article and Find Full Text PDF

Here, for the first time, we report the thallium (Tl) isotope record in moderately contaminated soils with contrasting land management (forest and meadow soils), which have been affected by emissions from coal-fired power plants. Our findings clearly demonstrate that Tl of anthropogenic (high-temperature) origin with light isotope composition was deposited onto the studied soils, where heavier Tl (ε(205)Tl ∼ -1) naturally occurs. The results show a positive linear relationship (R(2) = 0.

View Article and Find Full Text PDF

Aluminium (Al) speciation is a characteristic that can be used as a tool for describing the soil acidification process. The question that was answered is how tree species (beech vs spruce) and type of soil horizon affect Al speciation. Our hypotesis is that spruce and beech forest vegetation are able to modify the chemical characteristics of organic horizon, hence the content of Al species.

View Article and Find Full Text PDF

The behaviour of principal inorganic anions in forest soils, originating mainly from acid deposition, strongly influences the forest ecosystem response on acidification. The aim of this study was to describe seasonal and temporal changes of sulphate and nitrate contents and related soil properties under beech and spruce forests in a region heavily impacted by acidification. The Jizera Mountains area (Czech Republic) was chosen as such a representative mountainous soil ecosystem.

View Article and Find Full Text PDF

Soil acidification promotes Al release from minerals and parent bedrocks; it also affects Al mobilization and speciation. Speciation of KCl extractable and water-extractable Al in forest soils was done by means of HPLC/IC method. Species Al3+ were the most abundant Al forms in the KCl extracts (around 93%).

View Article and Find Full Text PDF

This study gives an overview of the health care reform in six Central European countries after the transition from a central planning system to a regulated market economy. We focused on cost containment policies for drugs, especially the requirements for submitting health economic data in the pricing and/or reimbursement processes. The literature review was supplemented with a survey with decision makers at national health authorities in each country.

View Article and Find Full Text PDF

Objective: To determine the patterns of consumption in calcium channel blockers (CCB) groups in the Czech Republic between 1992 and 1999 and make a comparison with selected countries.

Methods: This was part of a drug utilization study using WHO methodology [Anatomical Therapeutic Chemical classification/defined daily doses (ATC/DDD)]. The wholesale data collected by drug distributors were used.

View Article and Find Full Text PDF