Can Vitamin C Supplementation Improve the Antioxidant Capacity of Rhamdia quelen Fish Exposed to Atrazine?

Atrazine (ATZ) is one of the pesticides mostly widely used in Brazil; several studies have shown the toxic effects of this herbicide on aquatic organisms such as fish. Thus, it is absolutely necessary finding alternatives to protect the health of fish, mainly of species commercially important for aquaculture, which may be exposed to atrazine deriving from agricultural runoff. The aim of the current study was to investigate interactions between dietary supplementation with vitamin C (Vit C) antioxidant and exposure to ATZ in Rhamdia quelen fish exposed to this herbicide. R. quelen specimens were divided into four groups: (1) CTRL, (2) VitC, (3) ATZ, (4) ATZ + VitC. Groups 3 and 4 were exposed to ATZ (10 µg L^-1) for 96 h, after 30 days of VitC supplementation (1 g kg^-1). Liver samples were collected for biomarker assays. Group 4 was the only group presenting decreased protein carbonyl content. Non-protein thiol (NPSH) levels were significantly higher in groups VitC, ATZ and ATZ + VitC than in CTRL. Group ATZ + VitC presented significant increase in glutatione-peroxidase (GPx) activity in comparison to the other investigated groups. Ascorbic acid (AA) levels were significantly higher in group VitC and lower in group ATZ. Therefore, interactions between herbicide ATZ and dietary supplementation with Vit C have shown biochemical changes in R. quelen fish. Thus, dietary supplements with adequate amounts of Vit C can be added as antioxidants to the diet of fish bred in aquaculture systems in order to protect them from exposure to ATZ.

Ecotoxicological responses of Eisenia andrei exposed in field-contaminated soils by sanitary sewage

The disposal of untreated sanitary sewage in the soil has several consequences for human health and leads to environmental risks; thus, it is necessary investigating, monitoring and remediating the affected sites. The aims of the current study are to evaluate ecotoxicological effects on Eisenia andrei earthworms exposed to soil subjected to sources of sanitary sewage discharge and to investigate whether prevention values established by the Brazilian legislation for soil quality, associated with the incidence of chemical substances in it, are satisfactory enough to assure the necessary quality for different organisms. Earthworms' behavior, reproduction, acetylcholinesterase activity, catalase, superoxide dismutase and malondialdehyde levels were evaluated. The reproduction and behavior of earthworms exposed to sanitary sewage were adversely affected. Increased superoxide dismutase and catalase activity acted as antioxidant defense mechanism. Significantly increased lipid peroxidation levels and acetylcholinesterase activity inhibition have indicated lipid peroxidation in cell membrane and neurotransmission changes, respectively. Results have confirmed that sanitary sewage induced oxidative stress in earthworms. In addition, based on biochemical data analysis, the integrated biomarker response (IBR) has evidenced different toxicity levels in earthworms between the investigated points. Finally, results have indicated that effluents released into the soil, without proper treatment, lead to contaminant accumulation due to soil saturation and it can hinder different processes and biological development taking place in the soil. In addition, the current study has shown that physical-chemical analyses alone are not enough to assess soil quality, since it is also requires adopting an ecotoxicological approach. Brazilian legislation focused on soil quality must be revised and new guiding values must be proposed.

Occupational exposure of rural workers to pesticides in a vegetable-producing region in Brazil

The health of family farmers is at risk due to occupational exposure to pesticides. The aims of the current study were to investigate the level of farmers' perception of risks associated with pesticide use and to assess their health condition based on biochemical and immunological tests. Family farmers living in a vegetable-producing region in Southern Brazil were selected to participate in the study. More than 70% of the family farmers were often exposed to more than one type of pesticides; 41.2% were intensively using several pesticides for more than one decade and 74.4% were not using personal protective equipment (PPE) at the time of pesticide handling due to low perception of the risks posed by these chemicals. Enzymatic analysis performed in participants' blood samples showed changes in catalase (CAT) and glutathione reductase (GR) activity, in lipid peroxidation (TBARS) and carbonylated protein levels, as well as in chemoattractant (IL-8) and anti-inflammatory (IL-10) interleukin expression. Low perception of health-related risks posed by pesticides can be attributed to factors such as low schooling and lack of information, which put farmers' health at risk, as evidenced by blood biochemical and immunological changes.

Potential environmental toxicity of sewage effluent with pharmaceuticals

Sewage effluent effects on the biochemical parameters of Astyanax bimaculatus organs were investigateted. Treated sewage was collected in a treatment plant; 43 compounds, among them, pharmaceuticals and hormones, were investigated. Caffeine, ciprofloxacin, clindamycin, ofloxacin, oxytetracycline, paracetamol, sulfadiazine, sulfamethoxazole, sulfathiazole and tylosin waste was detected in the collected material. Fish were divided into four groups: control, TSE (treated sewage effluent), TSE + P (TSE with increased concentration of five pharmaceuticals) and PTSE (TSE + P post-treated with O₃/H₂O₂/UV). Biochemical parameters were evaluated in different organs after 14-day exposure. TBARS levels increased significantly in the brain of animals in the TSE and TSE + P groups in comparison to the control. There was significant reduction in TBARS levels recorded for the liver, muscle and gills of animals in the PTSE group in comparison to those of animals in the other groups. AChE activity reduced in the muscle of animals in the groups showing the highest pharmaceutical concentrations. CAT activity in the liver of animals in groups exposed to pharmaceutical effluent was inhibited. GST activity increased in brain of animals in the TSE + P and PTSE groups, whereas reduced levels of this activity were observed in liver of animals in the TSE group. Increased GST activity was observed in the brain of animals in TSE + P and PTSE groups. Based on integrated biomarker response values, the TSE + P group presented greater changes in the analyzed parameters. Results point out that pharmaceutical waste can cause oxidative stress, as well as affect biochemical and enzymatic parameters in Astyanax sp. Post-treatment can also reduce damages caused to fish, even in case of the likely formation of metabolites. Based on these results, these metabolites can be less toxic than the original compounds; however, they were not able to fully degrade the pharmaceutical waste found in the sewage, which can interfere in fish metabolism.