Evaluating the ecotoxicity of different pharmaceuticals using Aliivibrio fischeri bioassays

An endless list of companies have produced a large amount of pharmaceutical compounds in a year-on-year growth trend. Due to the excessive consumption of these substances and the inappropriate disposal, the environment was contaminated, especially aquatic ecosystems, with quantities of pharmaceuticals (PHACs) so that they have affected the living organisms, leading to decreased biodiversity and ecological degradation. Many studies on PHACs environmental presence and toxic effects were performed, but unfortunately, no limit was establish for discharging into environment, especially into the aquatic systems. The aim of this study was to use the bioluminescence of Aliivibrio fischeri bacteria as an indicator of toxically effect of different PHACs in simulated marine medium. The Microtox® bioassay is based on the PHACs inhibitory effect on the metabolism of bacteria which induced changes in their bacterial bioluminescence. The test organisms were exposed to analgesics and anti-inflammatories such as Diclofenac, Ketoprofen, Naproxen and Ibuprofen. The results showed that based on EC50 values, Naproxen had a very low toxicity but Diclofenac, Ketoprofen and Ibuprofen had a harmful effect on the aquatic organisms

Limnology and plankton diversity of salt lakes from Transylvanian Basin (Romania): A review

In the present work, we review the current knowledge on genesis, limnology and biodiversity of salt lakes distributed around the inner contour of Eastern Carpathian arc (Transylvanian Basin, Central Romania). Transylvanian salt lakes formed on ancient halite (NaCl) deposits following natural processes or quarrying activities.  Most of these lakes are located in eastern (Sovata area), southern (Ocna Sibiului), and western (Turda-Cojocna) parts of the Transylvanian Basin, have small surfaces (0.1-4 ha), variable depths (2-100 m), are hypersaline (>10%, w/v, total salts, mainly NaCl) and permanently stratified. As consequence of steady salinity/density gradient, heat entrapment below surface layer (i.e., heliothermy) develops in several Transylvanian lakes. The physical and chemical water stratification is mirrored in the partition of plankton diversity. Lakes with less saline (2-10% salinity) water layers appear to harbor halotolerant representatives of phyto- (e.g., marine native Picochlorum spp. and Synechococcus spp.), zoo- (e.g., Moina salina), and bacterioplankton (e.g., Actinobacteria, Verrucomicobia), whereas halophilic plankton communities (e.g., green algae Dunaliella sp., brine shrimp Artemia sp., and members of Halobacteria class) dominate in the oxic surface of hypersaline (>10% salinity) lakes. Molecular approaches (e.g., PCR-DGGE, 16S rRNA gene-based clone libraries, and DNA metabarcoding) showed that the O2-depleted bottom brines of deep meromictic Transylvanian lakes are inhabited by known extremely halophilic anaerobes (e.g. sulfate-reducing Delta-Proteobacteria, fermenting Clostridia, methanogenic and polymer-degrading archaea) in addition to representatives of uncultured/unclassified prokaryotic lineages. Overall, the plankton communities thriving in saline Transylvanian lakes seem to drive full biogeochemical cycling of main elements. However, the trophic interactions (i.e., food web structure and energy flow) as well as impact of human activities and predicted climate changes are yet to be assessed in these unique ecosystems with little or no match to analogous salt lakes worldwide

Radon Measurements and Radon Remediationin Băiţa-Ştei Pronearea

Băiţa-Ştei was the largest uranium reserve in Romania with estimated reserves of 450,000 tons of high grade metal. It was a large open pit mine in the northwest of Romania (West Carpathian Mountains), situated at 123 km south-east of Oradea, the capital of Bihor County. The transport during the time of sediment by Crişul Băiţa water course increased the uranium and radium content in the river meadow. The building material from Crişul Băiţariver bed (stone, gravel, sand) was used as construction material for the houses. In addition, some people living on this valley and surroundings after the opening exploitation used as building material the uranium waste from this mine. Preliminary indoor radon measurement (grab samples) in the villages situated on the route of ore transport (BăiţaPlai -Ştei) shown high radon concentrations, until 5000 Bq m−3. The new result obtained in this work in springer season 252 Bq m−3 is comparable with the annual means of 241 Bq m−3 and 229 Bq m−3 respectively, previously obtained, but more than twice times higher than the average value of 126 Bq m−3, computed for Romania. About 3000 of etched CR-39 track detectors were used followed by a selection of 20 houses proposed for remediation where a systematic investigation regarding radon sources was performed. The measured indoor radon concentration in the surveyed buildings ranged from 40 to 4000 Bq m−3. For experimental research, a representative pilot house was chosen. This house represents an example of a typical building from this area, with complex and various radon entry pathways which are correlated with the geology of soil. This building was chosen as pilot house due to the fact that it requires different ventilation systems or other remedial measures to be installe