Profile of micronucleus frequencies and DNA damage in different species of fish in a eutrophic tropical lake

Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species (Geophagus brasiliensis, Cichla temensis, Hoplias malabaricus, Astyanax bimaculatus lacustres, Oreochromis niloticus, Cyprinus carpio and Steindachnerina insculpita) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus, which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus, ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered

Early life stage tests with Brachydanio rerio and several polycyclic aromatic hydrocarbons using an intermittent flow-through system: Draft OECD Guideline

As part of a study carried out at the request of RIZA and the Ministry of Housing, Physical Planning and the Environment, the possible ecotoxicological effects of several Polycyclic Aromatic Hydrocarbons (PAHs) were determined in an Early Life Stage Test (ELS test). Effects on hatching, mortality, growth and the occurrence of egg and larval malformations in the fresh water species Brachydanio rerio were determined as laid down in the Draft OECD Guideline (ref. 1)

Use of Umbra pygmaea and Mytilus edulis to detect mutagens in the aquatic environment

Chemicals/CAS: aroclor, 12767-79-2; benzo[a]pyrene, 50-32-8; mesylic acid ethyl ester, 62-50-0; mesylic acid methyl ester, 66-27-3; triaziquone, 68-76-

Toxicity of bioavailable copper in relation to surface water organic matter: biological effects to Daphnia magna

Water quality standards for copper are usually stated in total element concentrations. It is known, however, that a major part of the copper can be bound in complexes that are biologically not available. Natural organic matter, such as humic and fulvic acids, are strong complexing agents that may affect the bioavailable copper (C