Occurrence of Volatile and Semi-Volatile Organic Pollutants in the Russian Arctic Atmosphere: The International Siberian Shelf Study Expedition (ISSS-2020)

Environmental issues in the Arctic region are of primary importance due to the fragility of the Arctic ecosystem. Mainly persistent organic compounds are monitored in the region by nine stationary laboratories. Information on the volatile (VOC) and semi volatile (SVOC) organic priority pollutants is very limited, especially for the Russian Arctic. Air samples from 16 sites along the Russian Arctic coast from the White Sea to the East Siberian Sea were collected on sorption tubes packed with Tenax, Carbograph, and Carboxen sorbents with different selectivity for a wide range of VOCs and SVOCs in 2020 within the framework of the International Siberian Shelf Study Expedition on the research vessel Akademik Keldysh. Thermal desorption gas chromatography–high-resolution mass spectrometry with Orbitrap was used for the analysis. Eighty-six VOCs and SVOCs were detected in the air samples at ng/m3 levels. The number of quantified compounds varied from 26 to 66 per sample. Benzoic acid was the major constituent, followed by BTEX, phenol, chloroform, bis(2-ethylhexyl) phthalate, and carbon tetrachloride. The study allowed for obtaining the first ever data on the presence of 138 priority pollutants in the air of Russian Arctic, whereas the thorough assessment of their possible sources will be the aim of a next investigation.

Catalytic Oxidation of Toluene Over LaNixB1-xO3 (B=Co, Cu) Perovskite Catalysts

A series of LaNixB1-xO3 (B=Co, Cu) perovskite catalysts were prepared by sol-gel method and employed in toluene degradation. The catalysts were characterized by XRD, UV-Vis, SEM and XPS to investigate crystal structure, morphology and composition of the catalyst. The effect of different calcination temperatures and time on the performance of perovskite catalysts for toluene degradation were investigated. And the CO2 selectivity was also carried out on as-prepared catalysts. The results showed that a small amount of Co-doping in B site of LaNiO3 could significantly improve its toluene degradation, while the substitution of Ni with Cu could not effectively enhance its activity. When the Ni/Co molar ratio in LaNixCo1-xO3 perovskite was 3:1, LaNi0.75Co0.25O3 catalyst exhibited the best activity, and it showed relatively short time and low temperature for toluene conversion of 100%. Therefore, LaNi0.75Co0.25O3 catalyst has a broad prospect in the degradation of volatile organic pollutants.

Evaluation of Asa River Water in Ilorin, Kwara State, Nigeria for Available Pollutants and their Effects on Mitosis and Chromosomes Morphology in Allium cepa Cells

T: This study evaluated water samples from Asa River in Kwara state, Nigeria, for cytogenotoxicity at 25.0 %, 50.0 %, 100.0 % following the Allium cepa assay. Onions were grown in the water samples for microscopic and macroscopic screenings. Heavy metals and volatile organic pollutants in the water were elucidated using AAS and GCMS techniques. The Water samples except the sample ‘C’ induced higher mitotic index (MI) than the negative control. Root growth was significantly promoted at 25.0 %, and significantly reduced at 50.0 % and 100.0 % of the sample ‘C’ and 100.0 % of the sample ‘A’. Water sample ‘A’ (100.0%) induced highest percentage chromosomal aberrations (CA) while the water samples ‘B’ and ‘C’ induced higher percentage CA than the negative control. Cadmium was detected at a concentration higher than its permissible limit in drinking water. Poly aromatic hydrocarbons, Aromatic amines, Acridine dye, Phenolic and Polychlorinated compounds were detected in the water sample. The observed proliferative, inhibitory, cytotoxic and genotoxic effects of the water samples on A. cepa cells suggest that Asa river was polluted, having potential to adversely affect humans, animals and plants utilizing it along its course. Keywords: Allium cepa; Asa River; cytogenotoxicity; Nigeria; pollutants

Screening of Asa River water in Ilorin, Kwara State, Nigeria for available pollutants and its effects on mitosis and chromosomes morphology in Allium cepa cells

Improper disposal of wastes as an environmental problem is common in African and other developing countries of the world, and it raises concerns due to its potential threats to the life of organisms in both terrestrial and aquatic ecosystems. In this study, Asa River in Ilorin, Nigeria was evaluated for cytogenotoxicity at 25.0 %, 50.0 %, 100.0 % following the Allium cepa assay. Water samples were collected from three points tagged A, B, C, and each point was 500 m apart from each other. The water samples were used to grow A . cepa for microscopic and macroscopic toxicities screenings. Heavy metals and volatile organic pollutants in the water were elucidated following the Atomic Absorption Spectroscopy and Gas Chromatography-Mass Spectroscopy. The Water samples induced higher mitotic index values, except the sample C which induced smaller mitotic index value than the negative control. Root growth in the exposed A . cepa was significantly promoted at 25.0 % of the water samples, while significant reduction was obtained at 50.0 % and 100.0 % of the sample C, and 100.0 % of the sample A. The absolute water sample A induced highest percentage chromosomal aberrations, as the water samples B and C induced higher percentage chromosomal aberration than the negative control. Cadmium was detected at a concentration higher than its permissible limit in drinking water unlike Zinc, Iron, Manganase. Poly aromatic hydrocarbons, Aromatic amines, Acridine dye, Phenolic and Polychlorinated compounds were detected in the water sample. These pollutants may be responsible for the observed proliferative, inhibitory, cytotoxic and genotoxic effects of the water samples on A . cepa cells. Our results suggest that Asa River is polluted, having potential to inflict different adverse effects on human, animals and plants utilizing it along its course.

Analysis of volatile organic compounds in environmental matrices by nitrogen-assisted headspace solid-phase extraction

A novel pretreatment method named nitrogen-assisted headspace solid-phase extraction (NA/HS-SPE) was developed for the analysis of volatile organic pollutants in water, sediment, honey, and juice.