Abstract: Background and Objective: Pesticides are chemicals designed and used to destroy and control pests that affect crops, thereby ensuring food security. Only a small fraction of the sprayed pesticides reach the intended pests, the rest find their way into the environment where they adversely affect non-target organisms. The toxicological effects of pesticide contaminated soil was assessed on selected biomarkers in Eisenia fetida to assess whether the pesticides under study have prooxidant properties which negatively impacts non-target soil organisms. Materials and Methods: Soil samples were collected from a private farm and a control site. The soils were analyzed for carbaryl and endosulfan. Earthworms were exposed to soils for up to 21 days. The earthworms were then analyzed for antioxidant enzyme activities, reduced glutathione and malondialdehyde levels. Two-way Analysis of Variance (ANOVA) in Tukey’s multiple comparison test was used to show statistical differences. Results: Carbaryl and endosulfan residues were detected in the soil from the farm. Enhanced activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and DT-diaphorase were observed. Malondialdehyde content was enhanced in earthworms exposed to the soil from the farm compared to malondialdehyde levels in earthworms exposed to the control soil. The activation of antioxidant and xenobiotic enzymes were a result of pollutants in the soil which included carbaryl and endosulfan. Increased malondialdehyde content indicated oxidative stress in the earthworms that were exposed to pollutant-contaminated soils, probably caused by the insecticides carbaryl and endosulfan present in the soil. Conclusion: The study highlighted the need of continued monitoring of pollutants in soil to safeguard the health of soil organisms. PubDate: 11 June, 2024
Abstract: Background and Objective: Coconut fibers, a byproduct derived from the coconut compound production process, can become waste as they are traditionally disposed of in improper locations, leading to pollution of beaches and cities in opposition to local laws, making them an environmental liability. In this study, the feasibility of reusing coconut fibers as reinforcement in expansive soil in Paulista, Pernambuco, was investigated through laboratory experiments. Materials and Methods: Samples of compacted soil and its mixtures with coconut fibers in weight proportions of 0.25, 0.50, 1.00 and 2.00% were tested. The following tests were conducted: Particle size analysis, consistency limits, compression, free swell, swell pressure, hydraulic conductivity and analysis of crack formation and propagation during drying. Classical statistical knowledge, descriptive parameters are used for initial knowledge of the data, was applied to statistical interference through analysis of variance for one and two factors, simple linear regression and multivariate analysis on principal components using Excel software. Results: With the addition of coconut fibers, there is a reduction in the soil’s swell pressure from 101.7 kPa for natural soil to 25.8 kPa for soil with 1% coconut fiber, a reduction of 74.63%. Tensile strength by diametral compression increases by 42% when adding 2% of fiber to natural soil. Regarding simple compression, shows a maximum stress increase of 57.49%. The hydraulic conductivity does not change significantly with the addition of fiber and did not exceed a permeability of (109 m/sec). The crack intensity factor (CIF) decreases as the fiber content increases. Conclusion: The inclusion of coconut fibers modifies the wide cracks that occur in natural soil into narrower cracks. The addition of green coconut fibers to expansive soil in Paulista improves all the geotechnical characteristics investigated in the expansive soil. PubDate: 01 August, 2024