Seasonal snow cover can serve as an informative single-season indicator of atmospheric deposition in industrial urban areas because it accumulates airborne contaminants during the winter period. A total of 55 snow samples were collected across the urban area, and the liquid phase was analyzed for major and trace elements using instrumental elemental analysis with defined detection limits and measurement uncertainty. Descriptive statistics, background comparisons, and integrated pollution indicators were used to characterize the spatial variability and intensity of contamination. The results showed that the median concentrations of most analyzed elements did not exceed the reference limits; however, aluminum and iron exhibited elevated levels, with aluminum reaching 1.1–27 times and iron 1.0–3 times the reference values. Median concentrations included 270 μg L⁻¹ for Al, 118 μg L⁻¹ for Fe, 30 μg L⁻¹ for Zn, 11.5 μg L⁻¹ for Ni, and 7.3 μg L⁻¹ for Pb. The obtained data indicate a heterogeneous pollution pattern across Pavlodar and suggest the combined influence of mineral dust, urban-industrial emissions, road-dust resuspension, and natural inputs on snow chemistry. Because the study is based on one winter sampling campaign, the results should be interpreted as a single-season assessment of snow-cover contamination rather than as evidence of long-term temporal stability.

During the period from 2019 to 2021, a series of experiments were carried out to study the uptake of tritium by crops in an area heavily contaminated with atmospheric tritium oxide (HTO), at the former Semipalatinsk test site in Kazakhstan. A quantitative assessment is given of the tritium uptake by typical crops (lettuce, tomatoes, peppers and beans) cultivated all over Kazakhstan in the case of a short-term tritium oxide vapor exposure. The plant samples were collected during and after exposure and analyzed for the tritium concentration in two chemical forms: tissue-free water tritium (TFWT) and organically bound tritium (OBT). During the entire series of experiments, the tritium concentration in free water from leaves and ambient air was of the same order of magnitude. The tissue water tritium concentrations of stems and edible parts was 1 to 2 orders of magnitude lower than in the surrounding air. The average value of the TFWT/HTO_atm ratio in the leaves and the edible part was (0.73±0.2) and (0.04±0.002), respectively. The organically-bound tritium concentration is 1–2 orders of magnitude lower than the tissue water tritium and ambient air concentrations. Under aerial tritium oxide uptake, the distribution of tritium in non-leafy crops was as follows: leaf–stem–fruit (in decreasing order). After exposure, a non-significant amount of tritium is firmly retained in plants for a long time. The tissue water tritium concentrations correlate closely with atmospheric tritium oxid (r = 0.76), correlate weakly with temperature (r = 0.43) and relative humidity (r = -0.43), and correlate moderately with solar radiation intensity (r = 0.56). There was no reliable correlation between the concentration of tritium in organic matter and in ambient air. The concentration of tritium in the free water of leaves is closely correlated with the concentration in the free water of the stems (r = 0.95) and fruits (r = 0.78). The organically-bound tritium concentration in leaves is closely correlated with the organically-bound tritium concentration in stems (r = 0.99) and fruits (r = 98). The results of the study should be considered when evaluating the impact of tritium oxide emissions on the population living near nuclear power.

Tightly bound tritium (TBT) in soil is poorly studied in terms of its bioavailability. This paper presents the results of long-term studies (2018 through 2023) on the bioavailability of tightly bound tritium in soil. Field studies were conducted in the epicentral zones of the Semipalatinsk test site (STS), using dominant and subdominant species. Laboratory tests were carried out in a greenhouse using different vegetable crops. The TBT concentration in the soil over the research period (2018-2023) significantly decreased from 57 to 28 кBq kg^-1 (a total decrease is 29 кBq kg^-1). TBT losses due to nuclear decay amounted to 14 кBq kg^-1 (48 %) and due to leaching, they were 15 кBq kg^-1 (52 %). It was found that the main leaching factor is water regime. The tritium concentration of soil solution is correlates with soil moisture (r = 0.47, p = 0.05). The obtained linear regression model can explain 48 % of the variation in tritium concentration in soil solution depending on soil moisture. The assessment of species differences in the uptake and incorporation of TBT from the soil under laboratory conditions, as well as the established values of the OBT_plant/HTO_soil и OBT_plant/TFWT_plant ratios indicate that plant roots are able to mobilize TBT into bioavailable forms. Thus, TBT in soil can be converted to a bioavailable form and migrate. This study is of great importance for comprehension of the mechanisms of tritium migration in the soil-plant system, which can help predict its behavior not only in ecosystems of STS but also in radioactive waste disposal areas.

One of the current issues of atmospheric pollution is particulate matter (PM). PM can be of both natural and anthropogenic origin. This review summarizes the current concepts of PM, as well as approaches to their classification and toxicological properties. The most significant and dangerous for the environment are particles with aerodynamic sizes of 2.5 and 10 micrometers (PM2.5 and PM10). The main sources of PM include construction, mining, fuel and energy enterprises, as well as road transport. The article provides a comparative analysis of the current environmental standards for PM2.5-10 in Kazakhstan, the Russian Federation, the EU, China, and the USA. In the EU, China, and the USA, there are no single maximum permissible concentration (MPC) limits for PM2.5, as is the case in the Russian Federation and Kazakhstan. However, the EU and USA have stricter average daily and annual MPC limits for PM2.5-10. Analysis of data on the continuous exposure to PM2.5-10 in the EU, China, and the USA has allowed us to identify the main risk groups associated with an increased risk of cardiovascular and respiratory diseases, as well as mortality. The complexity in assessing the toxic effects of PM2.5-10 stems from the significant variability and instability in their chemical composition, morphology, and dispersion properties. The main strategy for managing risks and improving public health outcomes is to reduce levels of PM2.5-10 pollution. In Kazakhstan, government measures to monitor and control the concentration of PM aim to reduce air pollution, but they have not been sufficiently effective in addressing public health risks.

The article presents characteristics of the plant cover at the “Aktan-Berli” site including the content of natural (⁴⁰K, ²³²Th, ²²⁶Ra) and artificial (¹³⁷Cs, ⁹⁰Sr, ²⁴¹Am, ^239+240Pu, ³Н) radionuclides. It has been found that the plant cover of the site is represented by ecosystems of high Kazakh hammocks bordering on ecosystems of lowlands in the west and ecosystems of ancient alluvial and modern alluvial plains. The content of free-water ³Н (FWT) and organic constituent (OBT) is below the detection limit of the methodological instrumentation in use (<8 Bq/kg). The concentration of natural radionuclides is typical, especially for Kazakhstani soil. The range of ⁹⁰Sr activity concentration in plants range from <0.7 to 6.7 Bq/kq, ¹³⁷Cs – from <0.6 to 1.1 Bq/kg, the content of ²⁴¹Am and ^239+240Pu are below the detection limit in most cases (<0,2 Bq/kg). Values of the radiation dose rate of plants are below the accepted international criteria. In general, the content of radionuclides in the plant cover of the “Aktan-Berli” site is significantly below the maximum permissible levels of radioactive contamination of forage plants posing no hazard when using the territory of interest for economic activities.

The article presents the results of a study on the effect of Sr-90 on the conductive tissues of the common bean (Phaseolus vulgaris) in three consecutive generations grown in a model experiment. The absorbed dose rate from internal and external radiation for each common bean generation during the growing season averaged 9.5·10⁻¹ G and 1.7·10⁻⁴ G, respectively. The thickness of the conductive tissues in 3 consecutive generations of beans varied in descending order: 1^st generation > 2^nd generation > 3^rd generation ≥ control group (p<0.05). Collectively, the established increase in the thickness of the conductive tissues of the stem and leaf in the 3rd generation of beans is a response to stress and is aimed at maintaining homeostasis at the tissue level of the biological organization. The obtained patterns characterize the mechanisms of plant adaptation to a high level of soil contamination with Sr-90 radionuclide.