Chemical management of aquatic macrophytes under simulated floodplain condition in mesocosms.

Floating natives (Eichhornia crassipes and Pistia stratiotes) and emergent exotic invasives (Hedychium coronarium and Urochloa arrecta) macrophytes grow as aquatic weeds in both natural and artificial floodplain areas in Brazil, where the chemical control should be researched. The herbicides glyphosate and saflufenacil, alone or mixed, were tested for weed control under simulated floodplain condition in mesocosms. Glyphosate (1,440 g ha-1), saflufenacil (120 g ha-1), or glyphosate (1,440 g ha-1) + saflufenacil (42, 84, and 168 g ha-1) were applied firstly; and 75 days after treatment (DAT), glyphosate (1,680 g ha-1) was applied as a follow-up treatment to control plant regrowth. An herbicide-free check was also used. Echhinornia crassipes was the species most susceptible to the different herbicides. Saflufenacil alone presented the lowest control on the macrophytes (≤45%) from 7 to 75 DAT, and in most cases they presented high regrowth rates, i.e., this herbicide was the least effective treatment in reducing the dry mass production of the macrophyte community. Glyphosate alone presented low efficacy to control H. coronarium (30-65%), but for the other macrophytes, it presented control peaks ≥90%, maintaining control levels ≥50% until 75 DAT. Glyphosate + saflufenacil, regardless rate of saflufenacil, caused similar damage to glyphosate in E. crassipes and P. stratiotes; however, in U. arrecta it caused 20-30% less injury. In contrast, these treatments provided the best control of H. coronarium. The complementary application of glyphosate was essential to improve the level of control of the first application, after plant regrowth.

Detection of anti-cancer drugs and metabolites in the effluents from a large Brazilian cancer hospital and an evaluation of ecotoxicology.

The use of chemotherapy agents has been growing worldwide, due to the increase number of cancer cases. In several countries, mainly in Europe countries, these drugs have been detected in hospitals and municipal wastewaters. In Brazil this issue is poorly explored. The main goal of this study was to assess the presence of three anti-cancer drugs, 5-fluorouracil (5-FU), gemcitabine (GEM) and cyclophosphamide (CP), and two metabolites, alpha-fluoro-beta-alanine (3-NH2-F) and 2'-deoxy-2',2'-difluorouridine (2-DOH-DiF), in effluents from a large cancer hospital, in the municipal wastewater treatment plant (WWTP) influent and effluent, and also to evaluate toxicity of the mixtures of these compounds by ecotoxicological testing in zebrafish. The sample collections were performed in Barretos Cancer Hospital of the large cancer center in Brazil. After each collection, the samples were filtered for subsequent Liquid Chromatography Mass Spectrometry analysis. The presence of CP, GEM, and both metabolites (3-NH2-F and 2-DOH-DiF) were detected in the hospital wastewater and the WWTP influent. Three drugs, GEM, 2-DOH-DiF and CP, were detected in the WWTP effluent. Two drugs were detected below the limit of quantification, 2-DOH-DiF: