[Toxicology of the hydrosphere]

The data are available on a superexponential growth in the production of chemicals the penetration of which into the earth surface water essentially deteriorates its quality. In addition to anthropogenic substances (biogens and xenobiotics alien to biosphere), hydrosphere is contaminated with algotoxin products of hydrobionts. The paper focuses on two important problems of hydrospheric toxicology--toxicological aspects of progressively growing process of anthropogenic eutrophia of the earth surface water and toxic damage to photosynthesis primary products. It is concluded that predominant ideas of the leading role of phosphorus in eutrophia and relevant theories as well as water quality standards based on trophism of water basin require correction. When assessed by trophism, water may appear oligotrophic but unsafe for population being contaminated with toxic substances and thus unfit for drinking, household and recreation purposes.