In the paper toxicity assessment of hospital wastewaters samples was performed using direct-contact tests consisting of five species, which represent three different trophic levels of the food chain. IC50 or EC50 values were estimated for each tested organism: Pseudokirchneriella subcapitata IC50/72h 18.77%, Daphnia magna EC50/48h 20.76%, Thamnocephalus platyurus EC50/24h 22.62%, Artemia salina EC50/24h 59.87% and Vibrio fisheri EC50/15min 46.17%. Toxic potential of hospital wastewater was described using a system of wastewater toxicity classification. The toxic units (TU) values estimated for each test indicate that hospital wastewaters are toxic (Class III). The variable results of the tests’ sensitivity confirmed the need of application of microbiotests battery with organisms of different trophic levels.
Zinc concentrations in apices [Zn 2+]apex of the lichens, Cladonia arbuscula and C. rangiferina were determined along transects through two sub-Arctic towns in the Usa River Basin, northeast European Russia. One transect, which was 130 km long running in an east-west direction, passed through the town of Vorkuta and the other transect, which was 240 km long running in a southwest-northeast direction, passed through Inta. Zinc accumulation in lichens, which was detected 25-40 km within the vicinity of Vorkuta, was largely attributed to local emissions of alkaline coal ash from coal combustion. The present results using C. arbuscula around Vorkuta are consistent with those of previous studies suggesting that this lichen is a useful bioindicator for trace metals. There was no such elevation of [Zn 2+]apex detected in C. rangiferina along the transect running through Inta.