Assessment of arsenic and heavy metal pollution in Chhattisgarh, India

Natural contamination of arsenic (As) and heavy metals (HMs) poses a health threat in many regions. Ambagarh Tehsil, Rajnandgaon, Central India, is a heavily polluted area due to mineralization of geogenic As and HMs in the environment, i.e., water, plants, and soil. In this work, contamination extents and sources of As and HMs (Cr, Mn, Cu, Zn, and Pb) in water, soil, and common plants were investigated to understand the main entry route of these toxic elements in human and domestic animals. The mean concentrations of total As in surface water, groundwater, surface soil, plant leaves, and animal stool samples of 0.031±0.009¿¿mg¿mL-1, 0.360±0.114¿¿mg¿mL-1, 192±65¿¿mg¿kg-1, 5.61±4.78¿¿mg¿kg-1, and 51.0±7.6¿¿mg¿kg-1, respectively, were found. The speciation, sources, enrichment, and toxicities of the As and other HMs are discussed, together with some associated health hazards, exemplified in domestic animals exposed to the contaminated water and food

Long-Lived Mantle Plume and Polyphase Evolution of Palaeoproterozoic PGE Intrusions in the Fennoscandian Shield

The NE Fennoscandian Shield comprises the Northern Belt in Finland and the Southern Belt in Karelia. They host mafic-ultramafic layered Cu-Ni-Cr and Pt-Pd-bearing intrusions. Precise U-Pb and Sm-Nd analyses indicate the 130-Ma evolution of these intrusions, with major events at 2.53, 2.50, 2.45, and 2.40 Ga. Barren phases were dated at 2.53 Ga for orthopyroxenites and olivine gabbro in the Fedorovo-Pansky massif. PGE-bearing phases of gabbronorites (Pechenga, Fedorovo-Pansky, Monchetundra massifs) and norites (Monchepluton) are 2.50 Ga old. Anorthosites of Mt. Generalskaya (Pechenga), the Fedorovo-Pansky, and Monchetundra massifs occurred at 2.45 Ga. This event produced layered PGE-bearing intrusions in Finland (Penikat, Kemi, Koitelainen) and mafic intrusions in Karelia. The Imandra lopolith dikes occurred at the final phase (2.40 Ga). Slightly negative εNd and ISr values (0.703–0.704) suggest that intrusions originated from an enriched mantle reservoir. Low 3He/4He ratios in accessory minerals (ilmenite and magnetite) indicate an upper mantle source. Large-scale correlations link the Fennoscandian Shield with the Superior and Wyoming cratons