GIS-based multi-criteria evaluation for olive mill wastewater disposal site selection

Journal of Material Cycles and Waste Management - The installation of an olive mill wastewater (OMW) disposal site without well-defined standards and constraints may cause undesirable long-term...     

Negative health effects in rats fed on sardine fishes

An adequate human diet should satisfy the requirements for energy and nutritive components including essential polyunsaturated fatty acids, essential amino acids, mineral components, vitamins, and fat. The benefits of the fish consumption are, however, often counteracted by toxic metals such as lead present in fish meat. Adverse effects of toxic metals on the aquatic environment and human health have aroused increasing interest in recent years. The achievement of an appropriate balance between the risks and benefits associated with fish consumption has therefore become a key health issue in current research. Therefore, we studied health impacts associated with the consumption of sardine fish, one of the most commonly consumed fish species throughout the world. Hepatic damages associated with the consumption of white or red muscle of sardine fish were explored and evaluated using a rat model. Rats were fed for 60 days with white or red sardine meat. Findings revealed (1) an elevated level of uric acid in the blood, (2) an accumulation of lead in the liver, (3) an atrophy of the liver, (4) an increase in plasma aspartate aminotransferase and alanine aminotransferase activities, and (5) an oxidative stress in the liver, including increased levels of lipid peroxidation and enhanced activities of superoxide dismutase, catalase, and glutathione peroxidase. Several abnormalities were also observed in liver histology. The alterations observed in the animals can be attributed to both the accumulation of lead and the high levels of purine in the sardine meat. The findings show that special attention should be given to the health effects associated with high intakes of sardine meat, particularly dark-meat sardine.     

Alteration of male reproductive system in rats fed on red or white meat from tuna fish caught in the Gulf of Gab��s in Tunisian coast

Fish, a widely claimed healthy food for humans, could also pose problems to health due to (1) accumulation of pollutants, especially heavy metals, (2) presence of marine toxins such as tetrodotoxin, ciguatoxin or okadaic acid and (3) metabolic production of large amount of uric acid which may crystallize in kidney or in articulations. As tuna fish represents a large part of the traditional food in some countries, the possible impact of its consumption on public health was investigated, with special attention to biochemical and histological alterations related to the genital function. For that purpose, white or red muscle from tuna fish was added for 60 days to the diet of male rats, and attention was paid to biochemical and histological alterations related to the genital function. Feeding rats with white muscle, and much more markedly with red muscle known to be more metabolically active, resulted in (1) an elevated uric acid level in blood, (2) an increase in lead level in testis, (3) an atrophy of the genital tract, including testes, epididymis, prostate and seminal vesicles, (4) a lowering of plasma testosterone level, (5) a decrease in spermatozoids number and motility, (6) an oxidative stress in testes including an increase in lipids peroxidation level and enhanced superoxide-dismutase, catalase and glutathione-peroxidase activities. We conclude that consumption of tuna fish meat, especially the dark one, should be reduced.     

Is frequent consumption of tuna fish safe? Evidence of liver damages in rats fed on red or white meat from tuna fish caught in the Gulf of Gab��s (Tunisian coast)

In recent years, a number of studies have clearly pointed out the nutritional benefits of fish consumption. However, some concerns about potential health risks derived from contaminants found in fish have also been raised. Therefore, balancing adequately the risks and benefits of fish consumption is currently a health key issue. As tuna fish represents a large part of the traditional food in some countries, the possible impact of tuna fish consumption on public health was investigated. Hepatic damages following consumption of tuna fish white (ordinary) or red (dark) muscle were evaluated in rat. Under our experimental conditions, feeding the animals for 60?days with white or, more markedly, red tuna meat resulted in 1) an elevated uric acid level in blood, 2) an accumulation of lead in liver, 3) an atrophy of liver, 4) an increase in plasma aspartate aminotransferase and alanine aminotransferase activities, and 5) an oxidative stress in liver including an increased level of lipids peroxidation and enhanced activities of superoxide dismutase, catalase and glutathione peroxidase. In addition, liver histology revealed several abnormalities. These alterations could be attributed to both lead accumulation and high purine levels in tuna meat. We conclude that attention should be paid to a possible health impact of frequent and important consumption of tuna fish meat, especially the dark one.     

Leachate generation and biogas energy recovery in the Jebel Chakir municipal solid waste landfill,Tunisia

A survey was conducted between 2006 and 2008 in order to identify municipal solid waste (MSW) composition and its influence on leachate generation and to assess the amount of biogas yield from the Jebel Chakir landfill in Tunis City. The organic fraction was the predominant compound in the MSW, followed by paper, fine, plastic, leather, rubber, metal, textile, glass and ceramic. The average MSW moisture content varies from 60 % in the wet season to 80 % in the dry one. The recognised MSW composition is well representative if compared to that of cities in developing countries. A large leachate quantity is produced in the landfill of Jebel Chakir, despite the negative water balance of the site. Based on the annual MSW landfilled quantities and using the LandGEM model, the expected peak landfill gas (LFG) production is estimated to occur 1 year after the landfill closure with a rate of 3.53 × 10⁷ m³/year. The analysis of the potential conversion of LFG to electric energy shows it at a total LFG-to-electricity energy of around 257 GWh with a heating value of 4,475 kcal/m³ based on an LFG collection efficiency of 33 % and energy efficiency of 33 % giving an economic feasibility for a 10 MW power plant.     

Soil contamination by heavy metals in landfills: measurements from an unlined leachate storage basin

Landfills are sources of groundwater and soil pollution due to the production of leachate and its migration through refuse. This study was conducted in order to determine the extent of soil pollution within and around the Jebel Chakir landfill, located in the Tunis City, Tunisia. The main objective was to characterize soil samples of an unlined storage basin in relation to heavy metal concentrations in the Jebel Chakir landfill to the southwest of Tunis, Northern Tunisia. Twenty-four soil samples taken from different locations around the storage basin were analyzed by atomic absorption spectrophotometry for Cr, Cu, Ni, Pb, and Zn investigation. Our results indicated high concentrations of Cr (54.4–129.9 mg/kg of DM), Zn (4.1–81.8 mg/kg of DM), Ni (15.1–43.9 mg/kg of DM), Pb (5.6–16.1 mg/kg of DM), and Cu (0.2–1.84 mg/kg of DM). These results suggested that contaminant migration is controlled by an active clay layer acting as an insulating material in the landfill. It is therefore necessary to set a treatment system for the landfill leachates and place a liner under the storage basin to reduce the pollution threat.     

High-performance biological treatment of tuna wash processing wastewater using Yarrowia lipolytica

Environmental Science and Pollution Research - It is well known that the lack of an effective treatment of tuna wash processing wastewater may pose substantial environmental and public health...     

Mechanical and thermo-physical characterization of mortars made with uncontaminated marine sediments

Journal of Material Cycles and Waste Management - In a context of sustainable development, civil engineering must increasingly use recyclable materials to preserve natural resources. Sediments...