Mar 2020 DOI 10.14302/issn.2691-3208.ijli-20-3268
Pesticides are the major source of concern as water pollutants. Chlorpyrifos (CPY) (O,O-diethyl-O-(3,5,6-trichloro-2-pyridinyl) phosphorothioate; CAS No. 2921-88-2). CPY is a widely used organophosphate insecticide. The aim of current study was to determine the effects of CPY on the second instar larvae of Culex mosquito as a bio-indicator of water pollution. Levels of CPY in stream water was evaluated. Toxicity of CPY was estimated on mosquito. Along with the evaluation of effects of water polluted with CPY on mosquito to predict the water pollution levels. Results showed that LC95 of CPY was 6331.30 mg/kg after 24hr and increased to 230506.4 ppm after 48hr of exposure. It was noted that the activity of CPY is concentration and time dependent. The 0.09 ppm concentration of CPY (the amount that was found in the stream water) had no effect on the second instar Culex larvae similar to the control (tap water). There is no effect after 72,96h of exposure of the population to the detected insecticide. It could be concluded that mosquito is not a bioindicator of CPY pollution at the detected level in stream water.
Oct 2019
Pesticides are the major source of concern as water pollutants. Persistent organochlorines can accumulate in food chains. Chlorpyrifos (O,O -diethyl O -(3,5,6-trichloro-2-pyridinyl) phosphorothioate; CAS No. 2921-88-2; CPY). CPY is a widely used organophosphorus insecticide that is available in a granular formulation for treatment in soil. Pesticides are used to control a wide range of pests including Mosquitoes. Mosquito borne diseases infect millions of people every year globally. The aim of current study was to screen the fresh water pollutants, water quality parameter in irrigation water from El Mahmodia stream, El-Beheira Governorate, Egypt and to determine the adverse effects of Chlorpyrifos on the larvae of Culex mosquito larvae as bio-indicator. The LC95 of Chloropyrifos insecticide was 6331.30 at 24h and increased to 230506.4 after 48h of exposure to the Chloropyrifos insecticide. It is noted that the effect of the exposure time of Chloropyrifos insecticide on the LC50, LC25 and LC95 values had a synergistic interaction with time, as it increased after 48h of exposure when compared to 24 h of exposure. The 0.09 ppm concentration of Chloropyrifos had no effect on the second instar Culex larvae, as there is no mortality over time; the same result is also with the control 0 ppm. There is no effect after 72, 96h of exposure of the population to the detected insecticide. This study concerns with studying the pollutants along El Mahmodia stream in El Beheira governorate in Abo Homs city with its abundance during the four seasons (2016-2017), as well as studding the physicochemical parameters in it. Another concern of this study is estimating the effect of one of this pesticides (Chloropyrifos) insecticide on the second instar Culex mosquito larvae, determining the lethal concentration of this insecticide on the Culex larvae. Along the study area, pesticides are used within a high ratio on the agriculture scale with its four main categories organophosphates, organochlorine, pyrthoid and carbamates. Organophosphates and organochlorine are used at a wide range. Pollutants measuring achieved by using GC-MS as water samples collected seasonally and analyzed, there is a big number of Pollutants which was found as well as other compounds which are banned, such as DDT. The physicochemical parameters Turbidity, COD, BOD in El Mahmodia stream exceeded the desirable limits of (Egyptian Law 48/1982), (WHO, 1993) and (FAO, 1985) although the other parameters as EC, PH, DO,TDS TSS are to be within the permeable limits. HCO3, NH4. Cu also was found to exceed the desirable limits while, Pb, Mn, Fe and Cd within the permeable limits. Chloropyrfos as an organophosphate pesticide used in the present study which was found with 0.09 mg/l in the stream water, used to estimate its effect on the Culex mortality, determining LC25, LC50 and LC95. The experiment continued for 96 h but after 48 h there is no effect of Chloropyrfos on Culex larvae. The experiment began with 20 second instar Culex larvae immersed in 100 ppm, 10 ppm, 1 ppm, 0.1 ppm and finally 0.09 ppm of Chloropyrfos insecticide with five repeats to each concentration, it is noted that the lethal concentration increase after 48h of experiment, the larval mortality decrease with time.
Dec 2018 DOI 10.14302/issn.2691-3208.ijli-18-2476
Bivalves are used as bioindicators of heavy metals pollution because they are known to concentrate these elements, providing a time integrated indication of environmental contamination. Trace metals can reach high concentrations in sediments and also in aquatic organisms by bioaccumulation through the food chain. Six heavy metals (Hg, Zn, Pb, Fe, Mg and Cu) were collected and investigated from Abu Hummus, El Behara. The concentration of Hg was high in winter as 2.3µg/g in sediment. The Zn concentration was high in summer in sediment as 8.1µg/g. The Pb concentration was high in winter in water as 3.3µg/l. The concentration of Fe in sediment was high in summer as 492 µg/g. The concentration of Mg was high in sediment as 408µg/g. The concentration of Cu was high in summer in sediment as 301µg/g. The mean concentrations of Fe in the present study are within the permissible limits of law 48/1982 (<1 mg/l) and the guideline of (WHO, 1993) which is <1 mg/l. The mean concentration level of copper is within the permissible limits of law 48/1982 (<1.0 mg/l). The mean levels of the heavy metals (Hg, Zn, Pb, Fe, Mg and Cu) detected in the present study in the water stream are less than the permissible limits recommended by (USEPA, 2005). In the present study there is a significance between all seasons in the protein content in the soft tissue of Spathopsisrubensas the mean concentration level in Spring was reported as 102.83mg/g which is higher then that of autumn 100.5mg/g, summer 93.33 mg/g and winter 80.50 mg/g. In the present study the mean activity level of GPx in spring was higher than the other seasons such as spring 31.33u/g ˃ summer 28.33 u/g ˃Autumn 26.67 u/g ˃ winter 20.50u/g. The mean activity level of SOD in summer was higher than the other seasons such as summer 38.83 u/g ˃ spring 33.33 U /g ˃Autumn 28.83U/g ˃ winter 22.83U/g. The mean activity level of CAT in spring was higher than the other seasons such as spring 25.67u/g ˃ summer and autumn19.83u/g ˃ winter 15.17u/g. The mean activity level of MDA in winter was 30.50 U/g ˃ summer 22.50U/g ˃ autumn 18.0 U/g ˃ spring 16.83U/g. In the present study it was found that the mean activity level of MDA increased in winter at the same time the mean activity level of CAT, SOD and GPx were decreased in winter. Negative correlation was reported between CAT and Hg in winter as r=-0.88*. A positive correlation coefficient in winter was found between SOD activity level and CAT activity level as r=0.838*.