Assessing potential hazard of technogenic formations of natural and man-made complexes of some sulphide deposits of the Eastern Zabaykalye

The analysis of chemical composition of technosol and soil samples from Akatuyevsky and Blagodatsky polymetallic deposit mines of the Eastern Zabaykalye revealed that the main pollutant in the soil samples is As. Material excess of the Maximum allowable concentrations was registered for Pb, Zn, Cd and Mn. Calculation of potential hazard coefficients showed that the most hazardous for the environment are man-made formations of Akatuyevsky and Blagodatsky mines. Of all the chemical elements which are most commonly encountered at the Akatuyevsky and Blagodatsky mines technosol the most hazardous are As, Pb, Zn and Cu. It is noted that these chemical elements are part of sulphide ore minerals.

Acceptable Limits for n-Hexane in Spacecraft Atmospheres

INTRODUCTION:The Spacecraft Maximum Allowable Concentrations (SMACs) for C2-C9 alkanes set by NASA in 2008 under the guidance and approval of the National Research Council specifically excluded SMACs for n-hexane. Unlike other C2-C9 alkanes, n-hexane can cause polyneuropathy after metabolism in humans or rodents and so requires more stringent SMACs than the other members of this group do. This document reviews the relevant published studies of n-hexane toxicity to develop exposure duration-specific SMACs for n-hexane of 200 ppm for 1 hour, 30 ppm for 24 hours, and 2.4 ppm for 7 days, 30 days, 180 days, and 1000 days.Garcia HD. Acceptable limits for n-hexane in spacecraft atmospheres. Aerosp Med Hum Perform. 2021; 92(12):956–961.

Ecological and geochemical features of the landscapes of the Baikal State Natural Biosphere Reserve

The aim of the study is a comprehensive assessment of the state of natural-territorial complexes of the Baikal State Natural Biosphere Reserve, including an ecological and geochemical assessment of soils, analysis of plant communities, determination of the ecological and biogeochemical features of the vegetation of the area. The distribution of mobile forms of heavy metals in the soils of the Baikal Biosphere Reserve has been studied. The coefficient of total soil pollution has been calculated. The maximum allowable concentrations exceedances for Cr, Mn, Cu and Pb were registered. Analysis of the microelement composition of the crust of Pinus sibirica showed the accumulation of Cd and Ni in relation to the Dobrovolsky clarke in all the studied areas of the reserve. Based on the studies carried out, it can be recommended to monitor the ecological state of natural territorial complexes on a regular basis on the territory of the Baikal State Biosphere Reserve.

Air pollution in the cities in Asian Russia: problems and prospects

in this article, we look at the issue of air pollution in cities in the Asian part of Russia, which are the industrial centres of the regions. Air pollution is shaped by a number of factors, including natural ones. In recent years, studies have been carried out in Russia and in foreign countries to determine the impact of pollutants emitted into the atmospheric air. There is a direct correlation between the state of public health and the amount of pollutants in the atmospheric air. Exceeding the maximum allowable concentrations in the air of territories threatens the life and health of people living in them. We have looked at the level of air pollution in cities, including the most polluted ones, and the measures taken by the government and large companies to mitigate the negative effects.

Accumulation of heavy metals in soil and litter of roadside plantations in Western Polissia of Ukraine

The article presents the results of a study on the influence of roadside forest belts of different species composition on the accumulation of heavy metals in soil and litter along roads of international and national importance in the conditions of Western Polissia of Ukraine. Mobile forms of Cd, Cu, Pb and Zn in soil and forest litter samples were determined in ammonium acetate extract buffer by atomic absorption spectrometry. The analysis of the content of heavy metals, their comparison with the maximum allowable concentrations depending on the composition of plantations and the category of the highway have been done. It is confirmed that roadside forest belts perform important functions in the accumulation of heavy metals in soil and forest litter. It is confirmed that roadside forest belts perform important functions in the accumulation of heavy metals in soil and forest litter. Among all the pollutants studied, the concentration of cadmium was the lowest and that of zinc the highest (especially in forest litter). Lead and copper in this indicator occupied an intermediate position. Despite the different species composition of plantations, the coefficient of concentration of heavy metals in the soil did not exceed the maximum allowable concentrations and was on average in the range of 0.10–0.20 of these indicators. The greatest effect of delaying the migration of heavy metals was observed in forest litter. Therefore, in order to effectively use the biological barrier along the roads, it is necessary to create linear protective belts of deciduous species with Acer platanoides, Betula pendula, Carpinus betulus and Tilia cordata, which give a rich annual litterfall.

Lampiran 5A paper Removal of nitrate, ammonia and phosphate from aqueous solutions in packed bed filterusing biochar augmented sand media

Nutrients from wastewater are a major source of pollution because they can cause significant impact on the ecosystem. Accordingly, it is important that the nutrient concentrations are kept to admissible levels to the receiving environment. Often regulatory limits are set on the maximum allowable concentrations in the effluent. Therefore, wastewater must be treated to meet safe levels of discharge. In this study, laboratory investigation of the efficiency of packed bed filters to remove nitrate, ammonium and phosphate from aqueous solutions were conducted. Sand and sand augmented with hydrochloric acid treated biochar (SBC) were used as packing media. Synthetic wastewater solution was prepared with PO43-, NO3-, NH4+ concentrations 20, 10, 50 mg/L, respectively. Each experiment ran for a period of five days; samples from the effluent were collected on alternate days. All experiments were duplicated. Over the experiment period, the average removal efficiency of PO43-, NO3-, NH4+ were 99.2%, 72.9%, 96.7% in the sand packed columns and 99.2%, 82.3%, 97.4% in the SBC packed columns, respectively. Although, the presence of biochar in the packing media had little effect on phosphate and ammonium removal, it significantly improved nitrate removal

Estimating Combined Health Risks of Nanomaterials and Antibiotics From Natural Water: a Proposed Framework

Nanoparticles are the major class of emerging contaminant detected at relatively high concentrations in aquatic environment. They are likely to co-exist with other chemical pollutants such as antibiotics in natural water systems. There are chances that if they are taken up orally, might pose adverse effects to human health. To address this issue, a risk framework is developed to study the combined exposure of nanoparticles and antibiotics in natural waters for the first time. The framework was applied to a hypothetical exposure of nanoparticles (CuO, ZnO, Fe3O4 and TiO2) and antibiotics (ciprofloxacin, CIP; ofloxacin, OFX; norfloxacin, NOR; levofloxacin, LEVO) to estimate human risks in a six-step approach for two different exposure scenarios i.e. availability adsorption isotherm data and vice versa. Risk was also estimated for the released fragments of antibiotics, nanoparticles and metal ions in the human digestive system. Mixture toxicity risk assessment was conducted for pairs (i) antibiotics and metal ions, (ii) antibiotics and nanoparticles, and (iii) nanoparticles and metals ions. Though the estimated risk values were observed to be less than 1 (both hazard quotients and hazard interactions less than 1) for all the conditions and assumptions made but it requires through monitoring of the studied contaminants in water to protect humans from their adverse effects, if any. Maximum allowable concentrations at which no risk occurs to humans was found to be (maximum values): antibiotics (233.8 µg/L, NOR); metal ions (1.02 × 109 mg/L, Ti2+ ions), and nanoparticles (6.68 × 105 mg/L, TiO2), respectively.

Agrochemical condition of soil in eco-farms of Akmola region

This article has studied the content of nutrients in the soil, their accessibility to plants. After studying the agrochemical study of the farm «Enbek» LLP on the availability of nutrients (N-NO3, P2O5, K2O, organic matter, pH, S2, Cu, Co, Zn, the content of humus and so on and so forth) potassium. Of the studied fi elds, fi eld №3-2 was distinguished by low nitrate nitrogen content. Humus content was low and varied from 3.46 to 3.86%. A low serum content (not more than 7.0 mg / kg) was noted. The content of micronutrients in the soil - suffi cient for growth and development of plants, exceeding the maximum allowable concentrations of metals in the soil was not detected. Subsequently, the studied soils of Enbek LLP can successfully be used for growing agricultural crops (wheat, lentils, peas, chickpeas, fl ax, rapeseed, soybeans, soybeans, soybeans, soybeans, etc.) Thus, monitoring of the soil allows to report observations on the state of the earth’s fund for their modern assessment, forecast and elimination of the consequences of negative processes. Key words: agrochemical research of soil, nutritional substances, organic products.

Hazardous Gas Analysis during Fire Investigation

Various types of hazardous substances are generated at fire scenes. Firefighters usually use the self-contained breathing apparatus (SCBA) during firefighting; however, SCBA is very inconvenient to use in other works (e.g., fire investigation and fire scene commands). Therefore, firefighters can be exposed to numerous chemicals. In this study, concentrations of hazardous gases were measured by utilizing gas analyzers with seven sensors during fire investigations. Six fire investigators measured the concentrations of hazardous gases directly as they worked. This included capturing the maximum concentrations of SO2 at seven places, HCHO at 29 places, NO2 at one place, HCN at 13 places, and CO at two places where the concentration exceeded the short-term exposure limit (STEL). When reconstruction experiments were performed, the maximum allowable concentrations for most hazardous chemicals fell below the STEL approximately 90 min after the fire occurrence. Therefore, we determined that fire investigators should wear proper respiratory protective equipment when working.

Fast Deoxynivalenol Determination in Cereals Using a White Light Reflectance Spectroscopy Immunosensor

Deoxynivalenol (DON) is a mycotoxin produced by certain Fusarium species and found in a high percentage of wheat and maize grains cultured worldwide. Although not so toxic as other mycotoxins, it exhibits both chronic and acute toxicity, and therefore methods for its fast and accurate on-site determination are highly desirable. In the current work, we employ an optical immunosensor based on White Light Reflectance Spectroscopy (WLRS) for the fast and sensitive immunochemical label-free determination of DON in wheat and maize samples. The assay is completed in 12 min and has a quantification limit of 2.5 ng/mL in buffer corresponding to 125 μg/kg in whole grain which is lower than the maximum allowable concentrations set by the regulatory authorities for grains intended for human consumption. Several extraction protocols have been compared, and the highest recovery (>90%) was achieved employing distilled water. In addition, identical calibration curves were received in buffer and wheat/maize extraction matrix providing the ability to analyze the grain samples using calibrators in buffer. Recoveries of DON from spiked wheat and maize grain samples ranged from 92.0(±4.0) to 105(±4.0)%. The analytical performance of the WLRS immunosensor, combined with the short analysis time and instrument portability, supports its potential for on-site determinations.