Assessment Of Some Organochlorine Pesticide Residues At Manzala Lake On Human Health, Egypt.

Hussien .M. EL-Shafei

General Authority for Fish Resources Development,

Port Said , Egypt.

Abstract.

Residues of organochlorine pesticides (OC) in fish (cat fish, tilapia, Liza ramada, and Anguilla anguilla) from Lake Manzala were analysed by gas chromatography. Residues of 5 OC pesticides (α -HCH (hexachlorocyclohexane); 0.016 g kg-1, β HCH; 0.34 g kg-1, , γ -HCH; 0.24 g kg-1, aldrin; 0.31 g kg-1, and dieldrin; 0.37 g kg-1) were found in Sediment samples, while 7 OC (Total DDT, dieldrin, α-HCH, β- HCH, β -HCH, aldrin and endrin) were observed in fish samples. One of them, β -HCH was found in all fish species’ muscle tissues. The OC concentrations determined in fish samples are lower than the other reported results. The average results were 0.51 g kg-1 for cat fish;1.25g kg-1 for tilapia;1.7 g kg-1 for L. ramada; 6 g kg-1 for A. anguilla. DDE/DDT ratio, which may be assumed as an indicator of the age of the contamination, is around or below the lower limit of the range characteristic for European countries. The results for hematology parameters of fish samples showed decrease in hemoglobin (Hb) % (g 100 ml.1), monocytes, hematocrit (PCV) and mean corpuscular hemoglobin content (MCHC), Also the results showed that lymphocytes (%) decreased slightly with fish contain high values of pesticide, while neutrophils (%) increased.This study shows that, the exposure to PCBs seems to continue in Egypt in spite of the fact that it was carried out on the limited number of subjects.The result of this study show that the Lake Manzala is contaminated with low levels of organochlorine pesticides. However, the levels of these chemicals in the fish species are expected to decline with time.

Keywords: bioaccumulation, organochlorine pesticides, xenobiotics , herbicides ,Lake Manzalla,

Sediment.

INTRODUCTION

Lake Manzala is a vast costal lagoon in the Nile Delta in Egypt, which receives much of the domestic pollution from Cairo and other city, Lake Manzala System located in the south-eastern part of Egypt. The surface area of the Lagoon in the past is 300000 ha now is 48000 ha. In the vicinity of this system there are agricultural areas and small settlements. Lake manzala Lagoon System is rich in terms of biological resources.(1). Organochlorine (OC) pesticides were the first synthetic organic pesticides that were used in agriculture. During 1960s and 1970s they were extensively utilized in order to protect crops and to prevent health disease. Nowadays they are banned or restricted in the majority of industrialized countries, but they are still used in Africa, South Asia, Central and South America (2,3).

DDT and BHC (now HCH) are probably the best known of these type of pesticides (4). These pesticides (DDT, HCH, aldrin, etc.), which are extensively used in agricultural and public health program are very persistent in nature Although persistence of OC residues is an advantage for insect control, it is another factor that has important environmental implications. Persistent OC pesticides are released to the environment as a result of their wide spread use in industrial, agricultural and domestic activities (5) Contamination of the aquatic environment by OC pesticides is a serious problem throughout the world. Many food chains in water and water environment receive the major amounts of the chemicals and other substances. Alteration of natural water environments could lead to a change in the behavior and health of fish species. (6)

Many authors have reported the accumulation and bio-magnification of OC in water, sediment, plankton, macro invertebrate, fish and waterfowl, in many aquatic ecosystems contaminated by the OC(7,8,9) cited that although the residues of OC were not found in water and plankton samples, various OC were determined in sediment and some fish samples collected in Köcegiz Lagoon System, Mugla, Turkey due to bio-magnification . The invertebrates act as the first link in aquatic food chain and mediate transport to predatory fishes. Similar results have been observed in crab and fish samples from the Gِksu Delta (7)

Exposure assessment studies indicated that humans are the final biological receptors for many toxic substances. There is limited information on the effects associated with the consumption of lakes fish. Given the implications of the association between contaminants in the Lakes and adverse human health outcomes, further research is necessary to illuminate the relationship between exposure, contaminant levels in human biological tissues and fluids, and the potential for adverse human health effects in these exposed populations(10)

However, these pesticides also produce adverse effects including widespread pollution of the natural environment on the global scale (11,12) and destruction of non-target organisms in the aquatic ecosystem especially fishes (13) and beneficial insects. High concentrations in edible fish may poison humans (14). Besides their effects on fish, herbicides have been reported to have deleterious effects on other components of the aquatic food chains. (15)

Results from recent laboratory studies also show that fish and other aquatic animals may accumulate chlorinated persistent residues from contaminated water system, (16,17,3)

The pattern of chlorine substitution is also important in the activation of the hepatic microsomal system Mixed Function Oxidase (MFO). This enzymatic system may transform xenobiotics, such as the polycyclic aromatic hydrocarbon, into metabolites that are more toxic than their parent compounds (18) The enzymes, also known as cytochrome P-450-mediated monooxygenases, constitute an important and highly variable group of enzymes which metabolize a wide variety of endogenous and exogenous lipophilic compounds-including steroid, fatty acid, prostaglandine, vitamins, polycyclic aromatic carcinogens, organochlorine insecticides, and polychlorinated and polybrominated biphenyls (19)

The objective of this study aims to determine pesticide residues, their concentration and origin in Lake Manzala. Evaluate the effects of acute levels on haematological parameters of cat fish, tilapia, Liza ramada, and Anguilla anguilla

This was chosen because it is of local economic importance and it is public usage from the Egyptian people and is common in Egyptian freshwater.

MATERIAL AND METHODS

The locations of sampling sites are as flow ( site 1 at Dameitta, site 2 at Port Said, site 3 at Matreia and site 4 at Bher albqer). All samples were collected between October 2005and April 2006.Sediment samples were collected by a dip net and were stored in a freezer (–20 C) until they were analyzed in the laboratory. Fish samples ( Liza ramada, Tilapia, Cat fish and Anguilla anguilla) were collected from fisheries co-operative and fishermen. Specimens were grouped by location, species, and length. Fish samples were stored in a freezer (–20 °C) till they were brought to the laboratory. Fish muscle (30 g fresh muscle tissues) were homogenised and extracted. The extracts were cleaned according to the procedure of Ross et al., 1981. Identification and quantitation of OC compounds was accomplished using reference solutions of deldrin, DDT, α -HCH, Β -HCH, γ –HCH, (lindane), aldrin, endrin, and heptachlor. Using these, 37–95% of OC compounds were recovered. Gas chromatography analysis was carried out using Carlo Erba HRGC 5300 with Ni-ECDs (Electron Capture Detector), 10% DC-200 and 4% SE-30/69 OV-210 columns at 170 °C. Temperatures of the detector and injector were 275 °C. Nitrogen was used at a flow rate of 35 mL min-1 as the carrying gas.

Blood was collected by cardiac puncture using heparinized syringes. Blood plasma was obtained by centrifugation at 1500 g for 15 min and stored in plastic screw top tubes at -18°C until analyses. The plasma obtained from each of four fish was pooled.

Hematocrit measurements were made by drawing well-mixed samples of blood into heparinized capillary tubes and centrifuging at 12500 rpm for 4 min (20). Hematological and biochemical parameters were measured, and averaged for statistical use. Hematocrit (Ht v/v ratio or %) was determined by microhematocrit method (21,22) and hemoglobin concentrations (Hb g/L) were determined by cyanometahemoglobin method (23). Red cell indices, mean corpuscular volume (MCV: µm3/cell), mean corpuscular hemoglobin (MCH: pg/cell), and mean corpuscular hemoglobin concentration (MCHC: g l-1) were calculated from RBC, Ht, and Hb according to(23). Results are presented as minimum, maximum and geometric means. Means, where the concentrations can not be detected were treated as zero. Pesticide detection limits were about 10 ppb and values below detection limits were recorded as Non-Detectable (ND).

RESULTS

The physico chemical feature of lake manzala water were estimated as per(24 ) in table (1), and are as followes, temperature.,23.45±0.6,dissolved oxygen.,6.3±0.3, conductivity 36x102±0.1, hardness 30.0±0.71 alkalinity 22.90±0.71 and pH 7.95±0.6.

As a result of the samples collected during the field surveys in Lake of Manzala; the OC pesticide residue in sediment and fish samples were analysed by means of gas chromatography method. Small amount of α -HCB, β -HCH, γ -HCH, aldrin and , from the group of OC pesticides were determined in Sediment samples at 4 sites (Table 3).

The highest and lowest concentrations observed in sediment sample at 4 sites PP' DDD (9.56_g kg-1) and aldrin (0.09_g kg-1) concentrations.

The order of OC as quantities are α -HCH > , β -HCH > γ -HCH > aldrin.

DDT, deldrin, α -HCH, β -HCH, γ -HCH, and aldrin were detected in the fish muscle tissues table (2&6). A positive result was obtained for at least one of the pesticide residues in each species of fish. The mean levels of the various OC residues in the four species of fish are given in Table (2). Presence of β-HCH and γ -HCH were observed in all the fish samples analyzed . Cat fish had the widest range of pesticide residues and the highest mean of pp' DDE (96_g kg-1). The results for hematology parameters of fish samples are presented in Table (4).

The results showed that fish contains high concentrations of pesticide were stressed as evidenced by a reduction in hematocrit (PCV),(10.2,17.5,2.5 and D ), hemoglobin(Hb)(3.1, 4.56. D .3.87 g100 ml.l),mean corpuscular hemoglobin concentration (MCHC)(24.9, 22.8, 15.1,and D),and monocytes (D. 2.00, 2.00, D) . Also the results showed that lymphocytes (%) decreased slightly with fish contain high values of pesticide(89.00 ,90.00, D, 9.00) while neutrophils (%) increased(7.00,7.00, D,9.00). for(Liza ramada ,cat fish, tilapia, , and Anguilla anguilla) respectively.

Table (6) represented the concentration of different pesticides in lake Manzala either in the sediments or in the fishes organs (liver and muscles) compared to the previously recorded data from Mediterranean regions. Data showed that The concentration of DDT in the Manzala lake sediment is lower than its concentration in the other regions and higher than its values in the Köcegiz Lagoon System, Mugla- Turkey , while Dieldrin is the highest compared to its concentration in the Köcegiz Lagoon System, Mugla, Turkey, Mississippi River and Mediterranean, Port-Said, Egypt since its concentration was below the detected limit. α –HCH and β–HCH concentrations are less than its values in the sediment of Köcegiz Lagoon System, Mugla, and Göksu Delta, Mersin, Turkey. β–HCH is higher than in the Mississippi river (below the detected limit). γ –HCH is less than, Göksu Delta, Mersin, Turkey and Mediterranean sea , Port Said- Egypt. Aldrin and Enidrin concentrations are also higher in the Göksu Delta, Mersin, Turkey and Köcegiz Lagoon System, Mugla than in lake Manzala , while Aldrin is higher than Mediterranean sea, Port-Said, Egypt. Moreover, the concentration of DDT in the Tilapia sp. is less than its value in the Maryut lake, Tana river, Kenya, Köcegiz Lagoon System, Mugla and lake Burullus.

Furthermore, the current investigation revealed that the concentration of DDT in different Tilapia sp. in the Maryut Lakes and lake Burullus, Egypt is over its concentration in the Manzala lake and higher than its values in Tana River, Kenya and Lake Burullus. α-HCH, β -HCH , γ -HCH , Aldrin concentration in fish from Maryut Lakes is higher than in fish from Manzala lake. Only γ –HCH conc. in fish from Tana River, Kenya is higher than its values in Manzala lake.

DISCUSSION

Pesticide pollution in sediment originates from agricultural activities in the vicinity.

It can be said that this pollution is the result caused by cultivation of cotton, fruit and vegetables in the fields surroundings the lake.Their use and their persistence in the environment resulted in residues observed in various concentration in the bodies water, soil, sediments and organisms. It is very well known that many areas were polluted by OC, even areas that are at a distance from the lands that were directly exposed (25). The OC residue levels in fish tissue determined in this study were compared with other authors’ results obtained from different studies performed at various locations ( 16,7,26,27,28,29,30).The OC concentrations determined in fish samples are lower than the other reported results (Table 6).

The most significant contamination present in the sample were the residue of DDT (principally pp' DDE) , the concentration of these substance as well as lindane and HCB are compared with those existing in other marine areas of Egypt (Biota) Lake Burullus., (30) and in similar environment in developing countries ( biota and sediment)( 31).

The data concerning Manzala Lake reveals rather low concentration of the substances measured .Additional oredence to this observation is given by rather constant inter – species organochlorine / lipid ratio (i.e. fish with more fat have a proportionally higher content of lipophilic contaminants (31). The OC concentrations determined in fish samples are lower than the other reported results .Another feature of the data is low percentage ( 1%) of pp' DDT in the sum of DDT and its principle degradation products, DDE& DDD. This confirms information that DDT is no longer employed in the immediations of lake manzala nor in its drainage basin .It is interesting to note that recent data from two other costal lake. Idku and Mariut revealed even lower total DDT and similarly low proportion of fresh pp' DDT. In contrast, values for fish taken from the open sea adjacent to Alexandria ( El Max and Abu Quir) though lower than those of Manzala had 10-20% fresh pp' DDT, perhaps reflecting continued usage in the Alexandria region (29). It is also interesting to note that DDT levels in lake Manzala are some what similar to those of the Karachi region (Pakistan) where DDT is still widely applied( 32).

DDE/DDT ratio, which may be assumed as an indicator of the age of the contamination, is lower than result of (30) 520.13 ugl-1 , and is around or below the lower limit of the range characteristic for European countries, typically between 0.6 and 2 (33,10,30) Thus, a relatively recent use of DDT could be hypothesized.

The public health implication of the chlorinated hydrocarbon data in the fish can be assessed by comparison of the measured concentration with the FAO/WHO recommended Acceptable Daily Intake (ADI). Such a risk assessment is shown in the table(5). Clearly, the percentage ADIs are extremely low and from dependence upon fish as a protein source. (34)

It is interesting to note that the concentration of pp' DDE in sediment near the major drains is rather high. This implies that : (a) The situation may have been worse in the past when DDT was more frequently applied, (b) The drainage channels may assist to degarde pp' DDT to its anaerobic degradation product pp' DDE prior to discharge into the Lake.

The high sedimentary concentration of DDE should not constrain the construction of artificial wetlands though care should be taken to avoid its remobilization. The same applies to PCB concentration which are elevated in the vicinity of the drains and should monitored carefully in the future.

These compound, sometimes regarded as "second generation pesticides" have rapidly replaced the persistent organochlorine compound for most pest control purposes . Some of the compounds however, are present in the marine environment for an appreciable period of time, particularly associated with sediments. They are usually characterized by a very high specific toxicity (often ten times higher than DDT) but for the most part are not readily accumulated in the living tissue. They are normally therefore associated with events for acute toxicity (fish kill) or cause a weakening of critical metabolic processes.( e.g. they all inhibit cholinesterase activity (30).

The application of hematological techniques is valuable for assessing fish health (35) and monitoring stress. The results showed that fish contains high concentrations of pesticide were stressed as evidenced by a reduction in hematocrit (PCV), hemoglobin(Hb) and mean corpuscular hemoglobin concentration (MCHC),and monocytes . Also the results showed that lymphocytes (%) decreased slightly with fish contain high values of pesticide, while neutrophils (%) increased.

The acute effect on the blood was further confirmed by the photomicrograph of the blood cells (3).The degree of elevation often indicates the severity of the infection. Tissue damage from other causes raises the neutrophile for similar reasons. The most common and important cause of neutrophilia is infection, and most infections cause neutrophilia. These effects on lymphocytes (%) and neutrophils of fish exposed to lower concentration are not statistically significant while those for fish exposed to higher concentration are significant as the blood cell were completely denatured (15). ( 36) showed that Poisonings, and severe disease, like kidney failure all cause neutrophilia ,lymphopenia and increased in neutrophile in heteropneustes fossilis, after an effect of dimethoate.

The blood cells were completely rendered senile with reduced size and indistinguishable cytoplasmic content. This could be due to increased fragility of the red blood cells as well as increase in rate of destruction of circulating erythrocytes (37,15).

The mode of action of pesticide on fish might be mediated through its effect on histology of the gills and liver .It induces lung, liver and kidney damage (38,39). The exact toxic mechanism is not clear but it is assumed to involve redox cycling and formation of Reactive Oxygen Species(ROS) (38,40,41) investigated the histopathology of the fish liver and brain exposed to pesticide showed a crowding of liver cells with congested sinusoid cells in tilapia which give a view to explain the toxic mechanism of pesticide.

CONCLUSIONS

This study shows that, the exposure to OC pesticides seems to continue in Egypt in spite of the fact that it was carried out on the limited number of subjects

The results of this study show that the Lake Manzala is contaminated with low levels of organochlorine pesticides. However, the levels of these chemicals in the fish species are expected to decline with time. The distribution of organochlorine pesticides in Lake Manzala seems more affected by local contamination than by long-range transport. The lake Manzala is heavily influenced by municipal sewage from Cairo and other government like Shrakia, Port Said, Dakhelia, and Damietta . The sewage influences the geochemistry by creating anoxic condition near the regions of discharge and by introducing anthropogenically derived contaminant. The anoxic conditions on one hand might enhance the degradation of such substances as DDT, On the other hand create an enormous ecological stress for the higher animals in the system. They also cause the rapid deposition of many trace metals to the sediment from which they may be remobilized at a later date if redox conditions change.

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Table(1) :Water quality values during assays at 4 sites :

Mean ± SD (n = 4)	Range	Parameters
23.45±0.6	21.9–25.	Temperature (.C)
6..3±0.3	4.2–8.5	Dissolved oxygen (mg L.1)
36×102±0.1	28–44×102	Conductivity (µmhos
30.0±0.8	23.0–37.0	Hardness (mg L.1 as CaCO3)
22.90±0.71	21.3 -22.5	Alkalinity (mg L.1)
7.95 ±0.6	7.5 - 8.4	pH

Table( 2): Concentrations , Mean± S.D and range of (OC) compounds in biota samples at 4 sites.

	Station 1		Station 2	Station 3	Station 4
	Liza ramda	Cat fish liver	Cat fish muscle	Cat fish muscle	A. Anguilla (Eel)	Small tilapia	Range	Mean ± S.D.
Α-HCH	0..32	N.D.	1.24	N.D.	1.65	0.045	1.65( 0.0-1.65)	0.54±0.72
Β-HCH	1.7	1.3	0.33	0.51	6	1.25	5.67(0.33-6)	1.84±2.09
γ -HCH	0.14	0.10	N.D.	0.09	0.72	1.1 < المصدر: Journal of Biochemistry letters Zagazig University . 4(52-70), (2008) Currently 0/5 Stars. 1 2 3 4 5 0 تصويتات / 647 مشاهدة نشرت فى 6 فبراير 2013 بواسطة husseinelshafe احفظ عدد زيارات الموقع 18,296

Dr.Hussien Mohammed Elshafei

Assessment Of Some Organochlorine Pesticide Residues At Manzala Lake On Human Health, Egypt.

Assessment Of Some Organochlorine Pesticide Residues At Manzala Lake On Human Health, Egypt.