Chemistry and acute toxicity of surface water, bottom sediments and riparian soils, Toyakha River catchment (Western Siberian Arctic), 2025–2026

Chemical composition (pH, redox potential, major ions, dissolved oxygen, BOD5, petroleum hydrocarbons, phenols, surfactants, benzo[a]pyrene, and Fe, Mn, Cu, Ni, Pb, Zn, Cr, Cd, Hg, Ba) and acute toxicity to Chlorella vulgaris and Daphnia magna of 59 samples (16 surface water, 16 bottom sediment, 27 soil). The samples were collected at eight sites and six interfluve plots of the Toyakha (Totayakha) River catchment (Tazovsky District, Yamalo-Nenets Autonomous Okrug, Russia; continuous permafrost tundra) in August 2025 and June 2026. Coordinates are generalised to 0.1°. See README.md for the data dictionary and methods.