Pesticide Contamination of Surface Water in Egypt and Potential Impact
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CATRINA (2009), 4 (1): 1 - 9 © 2009 BY THE EGYPTIAN SOCIETY FOR ENVIRONMENTAL SCIENCES Pesticide Contamination of Surface Water in Egypt and Potential Impact 2 Mustafa I. Selim1* and William J. Popendorf 1Environmental Health Sciences Division, Department of Health Education and Promotion, East Carolina University, Greenville, NC 27858. 2Department of Biology, Utah State University, Logan, UT 84322 ABSTRACT Enzyme-immunoassay field kits and capillary gas chromatography with nitrogen-phosphorous and electron capture detection (NPD and ECD) systems were used to determine the levels and distribution of commonly used pesticides (alachlor, atrazine, butylate, cyanazine, diazinon, metolachlor, metribuzin, malathion, parathion, propachlor, pendimethalin, trifluralin) and some of their metabolites (diethyl aniline, hydroxy alachlor, DE-atrazine, and DIP-atrazine) in surface water in Egypt. Replicate water samples were collected from several sampling sites near Cairo, Alexandria, Damietta, and Manzala Lake, using solid-phase concentration onto C18 cartridges, and the extract was subsequently analyzed using GC/NPD and GC/ECD systems. Alachlor, metolachlor, trifluralin, parathion, malathion, atrazine, and metribuzin were the most frequently detected pesticides, in the order listed, at the four sampling locations. Alachlor had the highest concentration detected (165-254 ppb), followed by metribuzin (0.6-47 ppb), metolachlor (6.6-12.5 ppb), atrazine, (2.5-7.3 ppb), and malathion (1.5-5.7 ppb). The concentrations of pesticides detected at Cairo were generally lower than those at the other three locations, down stream on the Nile River. The largest number of pesticides detected was in the Damietta branch of the Nile, and their concentration was generally higher than those detected at all other locations. Manzala Lake is the second highest location in terms of overall frequency and concentration of pesticides detected. The ecological and environmental health impacts of such contamination will be discussed. Key words: Pesticides, water, Manzala, Damietta, Cairo, Alexandria. INTRODUCTION Organochlorine pesticides such as endrin, dieldrin, The intensive three-crop agricultural cycle in the heptachlor, DDT, and lindane have been detected in Nile Delta has become heavily dependent on the marine organisms (Ernst et al., 1983), food samples application of large quantities of pesticides. Over (Abdel-Gawad and Shams El-Din, 1989, 1990; 300 trade name pesticides, manufactured by over 50 Dogheim et al., 1988, 1991), surface water (Fathi et al., chemical companies, are currently used in Egypt 1990; Khalifa, 1991), and agricultural drainage water (Selim and El-Sebae, 1995). During the period from and soil (Maklad et al., 1990; El-Gendy et al., 1991). A 1984 - 1988, a total of 41,368 tons of insecticides, previous study showed that drinking water treatment 17,854 tons of fungicides, and 12,021 tons of had partial effect on the levels of chlorinated herbicides were imported into Egypt. The imported pesticides in surface water (El-Sebae et al., 1989). pesticides include the main organophosphorous, Low levels of DDE and DDT were totally removed by carbamates, and pyrethroids groups. The use the water treatment, but HCH are not due to their pattern showed a positive increase in the use of greater solubility in water. insecticides (56.4% to 70.5%) of total-imported Detection and persistence of the organochlorine insecticides) and herbicides (21.3 to 28%) between pesticides in the Egyptian environment has discouraged 1984 and 1988 (Maklad, 1989). With the continuous their use and supported their gradual substitution with population growth and the need for increasing less stable, and presumed "safer pesticides." such as agricultural production, more pesticides are expected organophosphorous, carbamates, and synthetic to be imported and used in Egypt. The majority of pyrethroids. Organophosphorous pesticides were these pesticides are used to control pests and weeds introduced in early 1970's followed by synthetic in cotton, wheat, maize, rice, sugar cane, vegetables, pyrethroids in 1977 (Khalifa, 1990). In 1985 for and soy bean crops. example, 1,000 tons of organophosphorous insecticides, Aerial spray of pesticides (which has stopped 800 tons synthetic pyrethroids, and 550 tons carbamates years ago) resulted in residues finding their way to were imported into Egypt (El-Sebae, 1990). These humans, animals, and fish. However, manual quantities are expected to increase over the last ten application has also resulted in many documented years, due to their increased availability and cases of acute poisoning to humans (El-Wafd, 1993), acceptability as a substitute to organochlorine farm animals, honey bees (El-Sebae, 1990), and fish pesticides. The perceptions of "safer" pesticides have (El-Akhbar, 1991), due to direct dermal contact or lead to their extensive application and misuse which ingestion of contaminated food, water, or feed occurring resulted in the development of `pest resistance' (Khalifa, annually in Egypt. 1990; Selim and El-Sebae, 1995). To overcome “pest ____________________________________________ * Corresponding author: [email protected] Pesticide contamination in Egypt resistance” farmers resorted to multiple pesticide sites were located at the intake of the water treatment applications or formulating their own mixtures of plant at Kafr El-Battikh, at the intake canal for the pesticides. Many common name pesticides such as, Damietta water treatment plant (at Welad Hamam), alachlor and atrazine, became available as mixtures and on the river above and below the isolation dam at under different trade names (Selim and El-Sebae, 1995), Damietta (seals off the fresh water, approximately 15 which make it difficult to estimate the level or pattern of miles before the Mediterranean). The Manzala Lake usage for a given compound. However, there has been a location had two sampling sites of raw surface water, total lack of data on their levels or distribution in the one at El-Litha and El-Gameal. The four raw water Egyptian environment. Available literature has focused sampling were taken as close as possible to the center only on the neurotoxicity of organophosphorous of the sampled river or the canal and approximately pesticides (El-Sebae et al., 1977, 1980, 1988) and their one meter below the surface. A minimum of two residue in some crops such as onions (Hegazy et al., replicate samples for pesticide analysis was collected 1988) sugar beet roots and tops (Kady and at each sampling site. Przeezdziecki, 1985). Studies of pesticide residue in surface water in Egypt have focused mainly on Materials and Reagents organochlorine pesticides (Hassan et al., 1996; Osfor et Pesticide standards were 99+% pure, obtained from al., 1998; Abbassy, 1999; Abbassy et al., 2000; Gupta et ChemServices (West Chester, PA) or the USEPA al., 2003). However, to the best of our knowledge, (Research Triangle Park, NC). All solvents were J.T. monitoring data for pesticides other than the Baker pesticide residue grade (J.T. Baker Chemical organochlorine (endrin, dieldrin, lindane, and DDT and Company, Phillisburg, N.J.). Pesticide standard its metabolites DDE and DDD) group has been solutions were made up in isooctane. All pesticide extremely rare or non existent. solutions were stored in amber glass vials, sealed with Therefore, the primary objective of this preliminary Teflon tape, and stored in the dark at -4°C. The solid study was to investigate the problem of pesticide phase extraction cartridges were Waters Sep-Pack tC18 contamination of surface water in Egypt, particularly in (Environmental), containing approximately one gram of relation to pesticides that are widely used and for which the packaging material (Waters, Division of Millipore, monitoring data is lacking, such as alachlor and Bedford, MA). All glassware was cleaned with water triazines. and laboratory detergent, rinsed with methanol followed by acetone, and dried at 100°C. The use of MATERIALS AND METHODS plastic containers or septa was avoided, except for Teflon coated parts. Sampling Three sampling locations were selected along the Enzyme Immunoassay River Nile, one at Cairo and at its lower most parts The immunoassay kits used for the field and and output canals at Alexandria and Damietta (Fig. 1). laboratory screening were EnviroGard Triazines and A fourth sampling location was selected at Manzala Cyclodienes tube-Kits donated by Millipore Lake, which is the receiving body for agricultural Corporation (Bedford, MA). The Triazines Kit tests drain water. Multiple sampling sites were also for atrazine, Simazine, propazine, prometryn, ametryn, selected at each sampling location; three at Cairo simetryn, cyanazine, terbutylazine, trietazine, prometon, (population =17 million), four at Alexandria 6-hydroxy atrazine, DE atrazine, DIP atrazine, and (population = 4.4 million), eight at Damietta diazinon. The Cyclodienes kit tests for endrin, (population = 1.1 million), and two at Manzala Lake chlordane, dieldrin, aldrin, heptachlor, and (Egyptian Environmental Affairs Agency, 2006). At endosulfan. The kits are designed to be used for Cairo, one sampling site was for treated water at El- semiquantitative screening in conjunction with a Mohandsein and two sampling sites were for raw river portable differential photometer. The kits were used water. One at the University of Cairo bridge, the following the manufacturer procedures, which are second was approximately one Kilometer north of provided in the kits inserts. More