Ecotoxicological assessment of the Russian Museum gardens’ soils

Chemical, biological and toxicological parameters of the soils (gray-humus stratozems, or Hortic Anthrosols, and urbostratozems, or Urbiс Technosol) of the Russian Museum gardens were investigated (Summer Garden, Mikhailovsky Garden, Engineering Square). It has been established that these soils are highly fertile, characterized by environmental sustainability and have a high buffering capacity for pollutants. The content of pollutants (oil products, heavy metals, benz(a)pyrene) in the soils of the Russian Museum gardens exceeds the MAC and APC standards established in the Russian Federation. However, according to the results of biotesting on daphnia, unicellular algae and higher plants, all the soils studied are non-toxic. Water extracts from the studied soils have a reliable stimulating effect on the seeds of higher plants and green algae, increasing their growth by 30–50%. This is due, in our opinion, to the richness of the soil in nutrients and water-soluble humic substances. The results of determining heterotrophic (microbial) respiration show that the studied soils are characterized by stable and balanced functioning, as well as high ecological stability of the microbial cenosis to anthropogenic impact. It is necessary to correct the standards for the pollutants’ content in urban soils, basing such correction on the soil’s actual quality and health assessment at different levels of pollution.