An approach to the diazinon toxicity in the European eel: bioaccumulation studies

Abstract The acute toxicity effects of diazinon on European eel ( Anguilla anguilla ) were examined using short-term exposures in static conditions. In these conditions the 96-h median lethal concentration (LC 50 ) was 0.086 mg/1. In addition, the eels were exposed to two sublethal diazinon concentrations, 0.042 and 0.056 mg/1 (1/2 and 2/3 LC 50 96-h, respectively) for different exposure times, till a maximum of 96 h, and bioaccumulation and clearance of this insecticide in liver, muscle, gill and blood tissues were studied. BCF values of diazinon after 96 h exposure to 0.042 mg/l were 1850 in liver, 875 in gill and 775 in eel muscle. BCF values of diazinon over a 48-h exposure period to 0.…

Effects of Rosmarinus officinalis and Salvia officinalis essential oils on Tetranychus urticae Koch (Acari: Tetranychidae)

Laboratory trials were carried out to characterize Rosmarinus officinal and Salvia officinalis essential oils and to evaluate their pesticidal activities against Tetranychus urticae. Slide-dip and leaf-disk bioassays were employed to study the mortality caused by these plant oils on two-spotted spiders. Different dilutions of both essential oils (0.10-0.25%, v/v) caused acute contact toxicity, although the sage extract showed greater acaricidal activity than rosemary oil. Mortality rates of 95-100% were observed at all the sage oil dosages and when rosemary emulsions contained at least 0.20% of essential oil. In the residual contact experiments (leaf-disk assays), 0.15-0.25% of sage oil or …

PERSISTENCE OF SOME PESTICIDES IN THE AQUATIC ENVIRONMENT

Degradation and acute toxicity of Methidathion and Trichlorfon onProcambarus clarkii,in experimental conditions

Routine applications of organophosphate pesticides may adversely affect many nontarget organisms. Static toxicities in mature crayfish Procambarus clarkii were determined, in laboratory, for two organophosphate insecticides using 24, 48, 72 and 96‐h static tests. Three groups of 10 crayfish were exposed to 0.75 to 6 ppm for Trichlorfon and 0.2 to 0.9 ppm for Methidathion. The 24 to 96‐h LC50 values for Trichlorfon and Methidathion were from 5.14–0.99 ppm and 0.73–0.28 ppm respectively. Studies of degradation of Methidathion and Trichlorfon have been made using 1 ppm for Methidathion and 0.1 ppm for Trichlorfon. Both insecticides were degradated gradually until 96‐h. Results show that Methid…

Estudio de la actividad biocida de aceites procedentes de plantas aromáticas sobre Tetranychus urticae y Ceratitis capitata

Se ha estudiado la actividad biocida de aceites esenciales extraídos de plantas aromáticas como el romero (Rosmarinus officinalis L.) y la salvia (Salvia officinalis L.) sobre la araña roja (Tetranychus urticae Koch) y la mosca de la fruta (Ceratitis capitata Wiedemann). El aceite esencial de salvia a la concentración del 1% se mostró capaz de atraer adultos de C. capitata. La mayor actividad frente a la araña roja se observó por parte del aceite esencial de salvia, provocando, con gran rapidez, una alta tasa de mortalidad. El aceite de salvia al 0,25% consiguió reducir el nivel de puesta de T. urticae, llegando incluso a tasas de reducción de un 50%.

The effect of time, concentration and temperature on bioaccumulation in the gill of crayfish procambarus clarkii induced by organochlorine pesticides, lindane and endosulfan

Abstract 1. Crayfish were exposed to 1 25 th 96-hr lc 50 and 96-hr lc 50 of lindane and endosulfan for 1, 24, 48, 72 and 96 hr. 2. Concentrations of lindane and endosulfan were determined in gill tissue at 22°C and 29°C. 3. Clear differences were found in all concentrations, times and temperatures tested in gill tissues. 4. The highest accumulation of pesticide was found in the lc 50 endosulfan value.

Fenitrothion uptake and bioconcentration in the European eel(Anguilla anguilla)

Eels (Anguilla anguilla) were exposed to 0.02 mg/L of the organophosphorus pesticide fenitrothion during 144 hours in semi‐static conditions. BCF, intBCF, uptake rate constants (Ku) and elimination rate constants (Kd) of fenitrothion were determined in brain, gills, blood and muscle tissues of the eel. A simple one‐compartment model fitted the uptake and elimination characteristics. Plateau were reached at different times in the different tissues: at 24 hr in gills, 72 hr in brain and blood and 120 hr in muscle tissue. BCF were ranged from 117 for blood to 658 for muscle. Muscle tissue showed the highest BCF, intBCF, Ku and the lowest Kd .

Direct and indirect exogenous contamination by pesticides of rice-farming soils in a Mediterranean wetland.

It is known that the sources of soil contamination can be endogenous or exogenous and that exogenous contamination may be direct or indirect. In this work, an environmental pesticide fate study was conducted in soil profiles collected from 23 rice field sites in an important Mediterranean wetland (Albufera Natural Park, Valencia, Spain) from April 1996 to November 1997. Temporal and spatial distribution of 44 pesticide residues in an alluvial Mediterranean soil (gleyic-calcaric Fluvisol, Fluvaquent) were monitored. During this period, the levels of pesticide residues in different soil horizons (Ap1 0–12 cm, Ap2 12–30 cm, ApCg 30–50 cm, C1gr 50–76 cm, and C2r 76–100 cm) were investigated. In…

Bioconcentration and excretion of diazinon by eel.

Analysis of pharmaceutical biodegradation of WWTP sludge using composting and identification of certain microorganisms involved in the process.

Pharmaceuticals (PhCs) are organic contaminants that have been detected in wastewater, surface water, and soils throughout the world. The presence of 10 commonly used PhCs in Spain (azithromycin, benzylpenicillin, citalopram, fluconazole, fluoxetine, ibuprofen, irbesartan, olanzapine, telmisartan, and venlafaxine) was analysed at four wastewater treatment plants, and the changes in their concentrations during treatment were assessed. Although certain some PhCs were degraded in the treated water, their presence in sewage sludge increased in all cases. The sewage sludge was composted using rice straw to degrade the PhCs, and the composting efficiency was modified by changes in the relative C/…

Acute toxicity and bioaccumulation of endosulfan in rotifer (Brachionus calyciflorus).

Abstract 1. 1. The acute toxicity of endosulfan was determined for the freshwater rotifer Brachionus calyciflorus . 2. 2. The mean 24 hr lc 50 value for endosulfan was 5.15 ppm with a coefficient of variation of 14.7%. 3. 3. Rotifers were exposed at two sublethal concentrations (1.5–2.0 ppm) of endosulfan for bioaccumulation experiments, for an exposure time of 24, 48, 72 and 96 hr. The rotifers were fed with Nannochloris oculata (5 × 10 5 cell/ml). 4. 4. The highest accumulation of endosulfan was found 24 hr after the start of the exposure to 1.5 ppm of the toxicant. A steady-state concentration in rotifer was reached between 24–48 hr, followed by a gradual decrease until 96 hr.