Azhar Tashekova

This article presents the results of a study of the spatial distribution and occurrence forms of trace elements in the bottom sediments of the Karabulak Stream, located within the Degelen Mountains of the Semipalatinsk Test Site. Bottom sediment samples were collected at 19 points along the main stream channel and its four tributaries. A sequential extraction method was used to determine the occurrence forms of chemical elements. This method allows for the isolation of water-soluble, exchangeable, weakly specifically sorbed, organic matter-bound, iron and manganese oxideand hydroxide-bound, and residual forms. Quantitative determination of elements was performed using ICP-MS and ICP-AES. It was established that the distribution of trace elements in the bottom sediments is characterized by significant spatial heterogeneity due to the hydrological characteristics of the stream and the anthropogenic impact of the former test site. Exceedances of Clarke values were detected for a number of elements, primarily uranium, beryllium, molybdenum, and cadmium. The highest concentrations of Be, Sr, and Cd were observed in the upper reaches of the stream, while Mo and U contents increased in the lower reaches. Uranium in the bottom sediments of the main channel was shown to be predominantly in a watersoluble form, indicating its high migration capacity and potential environmental hazard.

This article presents the gross contents and chemical fractionation of trace elements in bottom sediments of the lower Shagan River. Twenty samples were collected at ten cross-sections between the outlet of Atomic Lake and the confluence with the Irtysh River. The point-by-point profiles show element-specific spatial patterns rather than one common accumulation zone. Local maxima of Li, Al, Cr, La, Ce, and Mn occur mainly 66–96 km downstream from Atomic Lake; Ga and Ba are higher in the upper part of the surveyed reach, while U and Mo show multiple separated peaks. Six fractions were identified: water-soluble, exchangeable, weakly specifically sorbed, organic-bound, Fe–Mn oxide/hydroxide-bound, and residual. Most elements, except Ga, had gross contents below upper continental crust values. Less than 20% was extracted using H₂O, Ca (NO₃)₂, and NaOH combined, whereas more than 70% of many elements occurred in poorly soluble forms.

Snowpacks serve as an informative deposition medium for assessing the spatial distribution of atmospheric fallout and technogenic load in areas with persistent snow cover. This study examined the chemical element content in the solid fraction of the snow cover (SFSC) in Pavlodar Region. Fifty-five samples were collected, covering industrial, buffer, non-industrial, and background zones. The elemental composition of the SFSC was determined using inductively coupled plasma mass spectrometry (ICP-MS). The results revealed marked spatial heterogeneity in the distribution of chemical elements. The Pb levels detected exceeded background values by a factor of 2 to 100, indicating a significant aerotechnogenic impact on the study area. Elevated concentrations (of Pb, Sr, and V) and peak accumulation levels were recorded in the zones directly affected by industrial facilities and in the corresponding buffer zones subject to this influence. Principal component analysis (PCA) identified two main factors of elemental composition variability. The first principal component (PC1) was characterized by high positive loadings primarily associated with rare-earth elements (REEs). The observed spatial pattern reflects a combination of local industrial impact and the regional transport of chemical elements. This study represents a pilot phase of long-term monitoring aimed at assessing the spatial distribution of chemical elements in snow cover and identifying areas of elevated technogenic impact.

The 2021 revision of the Environmental Code of the Republic of Kazakhstan was introduced to align with the World Health Organization (WHO) air quality guidelines and the national carbon neutrality strategy for 2060. The revised Code reflects a transformation of environmental governance, including the transition towards a low-carbon and climate-oriented policy framework, the tightening of air quality standards, the strengthening of environmental monitoring, the expansion of region-specific regulatory mechanisms, and increased emphasis on the implementation of Best Available Techniques (BAT). This study presents a comparative analysis of atmospheric pollutant emissions across regions and industrial sectors, including major pollutants such as PM_2.5, SO₂, CO, NO₂, and others. The analysis considers ambient air quality indicators, pollutant composition, the chemical composition of atmospheric precipitation, regional industrial profiles, and changes observed during the reform period. The findings demonstrate substantial regional and pollutant-specific heterogeneity in air-quality dynamics. Although stationary-source emissions decreased by approximately 5–6% between 2021 and 2024, no statistically significant improvement in the assessed ambient-air indicators was identified between 2021 and 2025. Persistent high pollution levels and episodic particulate matter exceedances remained evident in several cities. These findings provide an empirical basis for further assessment of the environmental outcomes of the revised Environmental Code.

Atmospheric pollution by fine particulate matter (PM_2.5) poses a severe threat to public health in industrial regions of Kazakhstan, such as Ust-Kamenogorsk and Pavlodar, where a sharp continental climate exacerbates toxic element accumulation. This study aimed to compare the elemental composition of PM_2.5 in Ust-Kamenogorsk and Pavlodar using ICP-OES (FPI EXPEC-6500) and ICP-MS (FPI SUPEC-7000), identify key pollution sources through chemometric approaches, and quantitatively evaluate inhalation health risks for adult and pediatric populations. Principal component analysis (PCA) revealed contrasting emission profiles: Ust-Kamenogorsk was dominated by non-ferrous metallurgical signatures, whereas Pavlodar was driven by high-ash coal fly ash from thermal power plants, ferrous metallurgy, and petrochemical operations. Non-carcinogenic health risks were exceptionally high in both cities, with cumulative hazard indices exceeding the safe benchmark (HI = 1.0) by over 500-fold, predominantly driven by extreme contributions of Zn (HQ_inh = 304.7) and Al (HQ_inh = 129.5). Carcinogenic risks for adults were governed by Cr and As, reaching 8.7·10⁻⁴ and 4.1·10⁻⁴ in Ust-Kamenogorsk, and 4.4·10⁻⁴ and 5.0·10⁻⁴ in Pavlodar, respectively—exceeding the maximum acceptable threshold (1·10⁻⁴) by up to 9-fold. For children, Cr presented an elevated risk (1.7·10⁻⁴) in Ust-Kamenogorsk, while borderline values were observed in Pavlodar.

Atmospheric deposition in industrial basins of Central Asia is strongly influenced by local emissions and wintertime dispersion conditions. This study characterized snowpack at 63 sampling stations across Ust-Kamenogorsk, Kazakhstan, including operational background station 1, on 24–26 February 2025 after a 116-day accumulation period. Major ions were determined in a spatially distributed exploratory subset of 16 samples, and trace elements were measured in samples from all 63 stations by means of inductively coupled plasma mass spectrometry and optical emission spectrometry. Mean meltwater pH and total dissolved solids were 6.55 ± 0.34 and 37.3 ± 18.0 mg L⁻¹, respectively. Charge-balance errors for the 16 hydrochemical samples ranged from −0.3% to +0.7%. Using the contamination index based on exceedances of the current Kazakhstan water-quality thresholds, 48 stations had CI < 1, seven had CI = 1–3, and eight had CI > 3; the highest value (60.21) occurred at station 26. Principal component analysis showed that the first three components explained 53.6% of the variance and separated a broad mineral/industrial aerosol association from a Pb–Cd–Zn association consistent with non-ferrous metallurgy and mixed urban sources. Cadmium was therefore interpreted as the principal contributor to the MPC-normalized index at the most affected stations, rather than as the dominant component by absolute concentration. The dissolved fraction can be mobilized during spring melt, indicating a potential pathway to soils and receiving waters, although direct ecological or human-health risk was not quantified. Station-level point mapping and projection along the NW–SE axis showed localized multi-element maxima rather than a monotonic citywide gradient.

Мақалада Қазақстанның өнеркәсіптік қалалары - Өскемен мен Павлодар атмосфералық ауасының сапасын зерттеуге арналған ғылыми жұмыстарға шолу жасалған. Зерттеу барысында PM2.5 және PM10 қатты аэрозольдік бөлшектеріне, сондай-ақ SO2, NOx және CO сияқты газ тәрізді ластаушы заттарға ерекше назар аударылды. Жұмыстың мақсаты - Қазақстан мен әлемнің өнеркәсіптік аймақтарындағы атмосфералық ауа мониторингінің қазіргі жағдайын талдау және аэрозольдік ластануды зерттеудегі ғылыми олқылықтарды анықтау. Кешенді зерттеулер санының шектеулі болуына қарамастан, елімізде PM2.5 және PM10 концентрацияларын, сондай-ақ басым улы газдарды бақылау бойынша белгілі бір эмпирикалық тәжірибе жинақталған. Бұл урбандалған және индустриялық аймақтардағы техногендік жүктеме деңгейін бағалауға және ауа ластануы құрылымы туралы бастапқы түсінік қалыптастыруға мүмкіндік береді. Жұмыстың ғылыми жаңалығы қатты аэрозольдік бөлшектердің физика-химиялық сипаттамаларын зерттеудегі отандық және шетелдік тәжірибеге салыстырмалы талдау жүргізумен байланысты. Шолу жұмысы барысында Қазақстанда қатты аэрозоль бөлшектерінің элементтік құрамы, морфологиясы және шығу көздерін зерттеу Еуропа, АҚШ, Қытай және Үндістан елдерімен салыстырғанда жеткіліксіз дамығаны көрсетілді. Аталған елдерде PM2.5 және PM10 аэрозольдік қатты бөлшектерін тұрақты массалық өлшеу жұмыстары спектроскопиялық және масс-спектрометриялық талдау әдістерімен үйлестірілген кешенді мониторинг жүйелері қолданылады. Мұндай тәсіл ластану көздерін дәлірек анықтауға және атмосфераға зиянды шығарындыларды азайтудың тиімді стратегияларын әзірлеуге мүмкіндік береді. Зерттеу нәтижесінде аэрозоль бөлшектерінің химиялық құрамын, маусымдық өзгергіштігін және кеңістіктік-уақыттық таралу заңдылықтарын анықтауға бағытталған кешенді зерттеулерді жалғастыру қажеттілігі туралы қорытынды жасалды.

East Kazakhstan has centers for smelting industry and large tributaries to the transboundary Irtysh river. three rivers were taken for research in the neighborhood of Ridder c.: Zhuravlikha, Tikhaya and Filippovka. Comparative characteristic was given to these rivers over 2023-2024, a chemical composition of water studied along the riverbeds, namely: acidity, hardness, concentrations of calcium ions, hydrocarbonate-chloride- and sulfate ions as well as total salinity. The waters of studied rivers are classed as (as classified by О. А. Alekina) with no excess of MPC established by the Kazakhstani legislation and range within the values recommended by the US EPA. The exception is the Filippovka riv., which exhibited hardness exceeding MPC in 2023. Most likely, this was due to a man-made accident that had took place the day before.

This article presents the potential use of a humic agent called ‘Superhumate’, obtained from weathered coal from the Shubarkol deposit in Kazakhstan. The experiment was conducted using model solutions and surface mine water samples from the “Degelen” site at the Semipalatinsk Test Site. The adsorption of heavy metals and toxic elements using the “Superhumate” agent was carried out under dynamic conditions using a chromatographic column. Tests were conducted at a natural pH range of 5–8 (mine waters) and with a model solution at pH 1.7. Assessing the sorption efficiency of this preparation revealed that at pH 1.7, the agent does not adsorb elements such as Cd, Cu, Pb, and Zn. Under dynamic experimental conditions, using the preparation for mine waters at natural pH levels (pH 5–8), elements such as Be, Sr, Mo, Cd, Cs, Zn, and U were efficiently adsorbed at levels of 60–95%. The sorption efficiency of Pb ions was found to be almost independent of pH. The experimental results obtained with mine water samples indicate that alkaline solutions have the highest sorption efficiency, with pH ≥ 7, which is attributed to the solubility of the agent.