Bull Environ Contam Toxicol (2013) 90:149–154 DOI 10.1007/s00128-012-0897-z Organochlorine Insecticide Residues are Found in Surface, Irrigated Water Samples from Several Districts in Bangladesh Alamgir Zaman Chowdhury • Mohammad Nazrul Islam Mohammed Moniruzzaman • Siew Hua Gan • Md. Khorshed Alam • Received: 3 August 2012 / Accepted: 12 November 2012 / Published online: 2 December 2012 Ó Springer Science+Business Media New York 2012 Abstract The purpose of this study was to investigate the occurrence and distribution of organochlorines such as aldrin, dieldrin, dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyltrichloroethane (DDT), endrin, lindane and heptachlor insecticide residues in irrigated surface water samples collected from 22 districts in Bangladesh. The concentrations of the pesticides were determined using gas chromatography mass spectrophotometry. Water samples from five locations (Feni, Nawabganj, Putia, Burichang and Chatak) were contaminated with DDT; the highest DDT concentration detected was 8.29 lg/L, and its metabolite, DDE, was detected at 4.06 lg/L. Water samples from four other locations (Natore, Sikderpara, Chatak and Rajoir) were contaminated with heptachlor residues, and the highest level detected was 5.24 lg/L, which is the above the maximum contaminant level recommended by the World Health Organisation. A water sample collected from Chatak, Sunamganj, was contaminated with both DDT and heptachlor pesticide residues. None of the water samples were contaminated with aldrin, DDD, dieldrin, endrin or A. Z. Chowdhury  M. N. Islam  M. Moniruzzaman  Md. K. Alam Agrochemicals and Environmental Research Division, Institute of Food & Radiation Biology, Atomic Energy Research Establishment, Ganakbari, Savar, Dhaka 1349, Bangladesh M. Moniruzzaman Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia S. H. Gan (&) Human Genome Centre, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia e-mail: shgan@kck.usm.my lindane. It is concluded that continuous, long-term monitoring and essential steps to limit the use of the pesticides in Bangladesh are needed. Keywords Organochlorine  Insecticide  DDD  DDE  DDT  Aldrin  Dieldrin  Endrin  Heptachlor  Lindane Agriculture is vital for the survival of the people in the agro-based country of Bangladesh. The major crops grown in the country are rice, wheat, jute, potato, sugarcane, vegetables and tea (Environment and Social Development Organization (ESDO) Bangladesh, November 2005). Because the widely cultivated, high-yielding plant varieties are highly vulnerable to pests and diseases, the use of pesticides is an inherent part of pest control practices in agriculture. Pesticides are substances intentionally designed to be toxic to living organisms for protecting crops, preserving foods, and controlling plant pests. These pesticides are applied to soil or sprayed over crop fields and are exposed to the environment, especially natural waters (Bagchi et al. 2009). There are many types of pesticides, and organochlorine and organophosphorous compounds are the most widely-used. The organochlorinated pesticides’ persistence and semi-volatile natures enable them to be transported to remote, native regions by air, water or other means. Various studies conducted all over the world have found organochlorinated pesticides in different matrices, such as water, air, fish, soil, solid wastes and human tissues (Cuadra et al. 2006; Zuo et al. 2002), thereby indicating that organochlorinated pesticides are ubiquitous in the environment and can pose a threat to human health. The use of these chemicals were banned or severely restricted in all developed countries at the beginning of the 1970s 123 150 (Vighi and Funari 1995), but in Bangladesh, they were not banned until 1993 (Matin et al. 1998). According to a study conducted by Environment and Social Development Organization (ESDO), a local nongovernmental organization, the illegal use of organochlorine pesticides in agriculture in developing countries, especially South Asian countries, continued for many years after their ban (Environment and Social Development Organization, ESDO; Bangladesh, November 2005). Due to the use of pesticides in agriculture, pond waters around paddy fields can be contaminated via transportation from agricultural surfeit of rainwater from the crops’ fields. In addition, ground water can become contaminated with pesticides by leaching or infiltration of rainwater from the crops’ fields (Vighi and Funari 1995). Therefore, monitoring pesticide residues in water samples can help minimize potential hazards to human health. Some of the potential hazards to humans and other animal species include cancer; neurological, behavioral, immunological and birth defects; and reproductive problems (Chevrier et al. 2008; Jacobson and Jacobson 1996). There is an interest in investigating these substances because of their long residence times in the environment and their potential to pollute other resources. Although pesticides have been legally and illegally used in considerable quantities at different locations in Bangladesh for many purposes, there is a lack of information on the levels of pesticide residues in environmental water samples; however, this information is important because the water is used for irrigation. In this study, we randomly selected water samples from 22 districts in Bangladesh to determine the pesticides’ levels and the possible impact on the environment. Materials and Methods A gas chromatography-mass spectrometer (GC-MS) (Finnigan Trace GC ultra, Model No. K04244B24500070, Finnigan Trace DSQ, Model No. Trace DSQ-Mass Spectrophotometer) with evaluating software Xcalibur (Ver. 1.3.1, Thermo Electron Corporation) was used for determining the pesticide concentrations in the samples. The capillary column was a TR-5 MS boned fused silica column (30 m 9 0.25 mm 9 0.25 lm film thickness). Aldrin (98.50 %), dieldrin (98.30 %), dichlorodiphenyldichloroethane (DDD)-99.50 %, dichlorodiphenyldichloroethylene (DDE)-97 %, dichlorodiphenyltrichloroethane (DDT)-98 % and heptachlor (99.50 %) standards were purchased from GmbH (D-86199 Augsburg, Germany). Endrin (98.00 %) and lindane (100.00 %) standards were purchased from AccuStandard (125 Market St., New Haven, CT 06513, USA). Anhydrous sodium sulfate (Na2SO4) was purchased from Merck, Germany while florisil and 123 Bull Environ Contam Toxicol (2013) 90:149–154 magnesium silicate (mesh 60–100, active at 1,200 °F) were purchased from Sigma, USA. The n-hexane solvent (Merck, Germany) was of laboratory reagent grade, and the diethyl ether was of IR Spectrum grade (BDH, England); both solvents were glass-distilled before use. Surface, irrigated water samples (n = 25) were randomly collected from different districts in Bangladesh according to the instructions outlined by Hunt and Wilson (1986) and the APHA (1995). Samples were collected between June 2011 and August 2011, which was the rainy season. The sampling locations were spread throughout Bangladesh in 22 districts: Feni, Noakhali, Laxmipur, Nawabganj, Rajshahi Sadar, Putia, Naogaon, Natore, Chandpu, Comilla, Brahmanbaria, Bandarban, Khagrachari, Chittagong Hill tract, Rangamati, Moulovibazr, Habiganj, Sylhet, Sunamganj, Madaripur, Faridpur and Rajbari (Table 2). Following sample collection, the samples were transported to the lab as quickly as possible in sealed glass bottles on ice. The samples were then stored at -20°C until further processing. An individual water sample (500 mL) and a positive control (refer to positive controls section) were placed in a 1,000 mL separating funnel fitted with a glass stopper. Extraction was conducted with 100 mL of double distilled n-hexane and 2 mL of diethyl ether in a Multi-Shaker (Max-4000, Guyson Corporation, USA) for 15 min at 150 rpm. The solution was then allowed to settle for 15 min. The n-hexane and diethyl ether extract was separated and collected in a conical flask. Two further extractions using a 50 mL double distilled n-hexane and 2 mL diethyl ether solutions were completed using a similar procedure. The n-hexane and diethyl ether extracts were combined and treated with 10 g anhydrous sodium sulfate to remove traces of water. The water-free extract was evaporated in a rotary vacuum (Buchi, Switzerland) to a small volume (1–2 mL) and transferred into a clean vial; then, the solvent was completely evaporated with nitrogen gas. Finally, the extract was dissolved in n-hexane to a final volume of 5 mL (DFG 1987). The extract sample was cleaned up based on the method described by Bagchi et al. (2008). Briefly, the extract was passed through a column (10 mm ID) packed with 5 g of deactivated florisil (60–100 mesh). The top 1.5 cm of the florisil column was packed with anhydrous sodium sulfate. This extract was eluted with 100 mL of 2 % double-distilled diethyl ether into double-distilled n-hexane at a rate of 5 mL/min. The eluate was concentrated using a rotary vacuum evaporator (Buchi, Switzerland) and transferred to a glass vial. Solvents were dried with nitrogen gas. The evaporated sample was dissolved in n-hexane, and then 2 mL was analyzed by GC–MS. Four hundred microliters each of aldrin, dieldrin, DDE, DDD, DDT, endrin, lindane and heptachlor drug standards (100 ng/lL) was added to Bull Environ Contam Toxicol (2013) 90:149–154 500 mL of blank water samples in triplicate as positive controls. The controls were allowed to interact with the sample for 10 min. Subsequently, the fortified sample volumes were processed to 2 mL before injection into the GC–MS. The chromatograms of the drug standards are shown in Fig. 1a. The oven temperature was initially programmed to 45°C, and it was increased to 130°C at the rate of 65°C/min and held there for 2 min. The temperature was increased up to 180°C at 12°C/min, 240°C at 7°C/min and then 320°C at 12°C/min. The injector, MS transfer line and MS heater temperatures were maintained at 250°C. High-purity helium carrier gas (99.99 %) was used. The flow rate of the carrier gas was maintained at a linear velocity of 30 cm/sec. Vacuum compression and septum purge were appropriately set for each pesticide tested, and the suspected pesticide was identified by comparing the retention time of the pesticide with the retention time of the pure analytical standard. The amount of pesticide was quantified using freshly prepared standards as described by (Chowdhury et al. 2012). The calibration curves for aldrin, dieldrin, DDE, DDD, DDT, endrin, lindane and heptachlor were prepared in triplicates using amounts from 5–20 ng. Standard solutions and positive controls for aldrin, dieldrin, DDE, DDD, DDT, endrin, lindane and heptachlor were injected into the GC–MS in triplicate, and the percentages of each drug recovered were calculated based on the equation: % Recovery = ½CE = CM  100 where CE is the experimental concentration determined from the calibration curve and CM is the maximum concentration expected. The mean recovery percentages of aldrin, dieldrin, DDE, DDD, DDT, endrin, lindane and heptachlor in the spiked positive controls samples that underwent florisil clean up were consistent with those recommended by the FDA (DHHS, 2001) and had values of 91.25 %, 87.50 %, 86.50 %, 89.75 %, 93.25 %, 86.00 %, 91.75 % and 84.75 %, respectively (Table 1) indicating that the analysis was suitable. Results and Discussion Water samples from five locations (Feni, Nawabganj, Putia, Burichang and Chatak) contained DDT residues. From this number, samples from four locations had levels higher than what is recommended by the World Health Organisation (WHO). The sample collected from Burichang, where agriculture is the main activity, had the highest concentration (8.29 lg/L) of all of the samples (Table 2 and Fig. 1b). This high concentration was likely due to heavy usage of pesticides. However, the concentration is lower than the 19.6 lg/L concentration reported by 151 Table 1 % Recovery of aldrin, dieldrin, DDD, DDE, DDT, endrin, lindane and heptachlor—GC Method Compound Amount (ng) in GCa Recovery % Spiked Measured Aldrin 20.00 18.25 Dieldrin 20.00 17.50 87.50 DDE DDD 20.00 20.00 17.30 17.95 86.50 89.75 DDT 20.00 18.65 93.25 Endrin 20.00 17.20 86.00 Lindane 20.00 18.35 91.75 Heptachlor 20.00 16.95 84.75 a 91.25 Mean value of three replicates (Matin et al. 1998) obtained from a water sample collected in Begumganj, Bangladesh, which is known for its industrial activities and its supply of natural gas. In addition, high concentrations of DDTs were found by (Wu et al. 1999) in the river sediments from northern China where a factory with a high manufacturing capacity of DDT is located. The lowest concentration of DDT residue was found in Putia, Rajshahi. The 0.133 lg/L concentration found at this site was below the 2.0 lg/L value recommended by the WHO guidelines for drinking water quality (WHO 1996). Although agricultural products such as rice, wheat, potatoes and lentils are produced in Rajshsahi, this district is more known for tourism and has had minimal industrial development. Another study was conducted on the presence of organochlorine residues in water samples from irrigation canals in the Meghna-Dhangonda irrigation project, Bangladesh reported levels of between 0.20 and 6.75 ng/L (Alam et al. 1999), indicating that the pesticide levels may vary from region to region. However, the disparity in the concentrations may be due to seasonal variations, environmental factors, previous and current use of the pesticides and the physicochemical properties of the pesticides used. Therefore, it is important to sample from as many regions as possible. In the 1980s, high quantities of organochlorines were used in both agriculture and public health before a ban in 1993 in which heptachlor was exempt (Matin et al. 1998). It was estimated that approximately 100–300 tons of formulated organochlorines, particularly DDT and lindane, were used annually between 1990 and 1993 in Bangladesh for the control of malaria (Matin et al. 1998). Nevertheless, sufficient stocks of DDT, which are under government control, remain in the country for emergency situations. In 1994, DDT was allowed to be used by members of the public as an immediate measure to control plague, which claimed many lives in India. Because India is a neighbor of Bangladesh, it is possible that 123 152 Fig. 1 (12.54 (15.84 (17.83 Bull Environ Contam Toxicol (2013) 90:149–154 (a) Chromatogram of the mixed standards of heptachlor min), aldrin (13.39 min), dieldrin (15.96 min), DDE min), endrin (16.47 min), DDD (16.88 min) and DDT min); (b) Chromatogram of DDE (15.84 min) and DDT 123 (17.81 min) in a water sample (WS-11); (c) Chromatogram of heptachlor (12.52 min) in a water sample (WS-08); (d) Chromatogram of heptachlor (12.56 min) and DDT (17.83 min) in a water sample (WS-22) Bull Environ Contam Toxicol (2013) 90:149–154 153 Table 2 Concentrations of pesticides (aldrin, dieldrin, DDD, DDE, DDT, endrin, lindane and heptachlor) (lg/L) in irrigated field water samples (n = 25) Sample ID No. Location Aldrin Dieldrin DDE DDD DDT Endrin Lindane Heptachlor WS 01 Feni sadar, Feni ND ND ND ND 4.16* ND ND ND WS 04 Nawabganj sadar, Nawabganj ND ND ND ND 3.01* ND ND ND WS 06 Putia, Rajshahi ND ND ND ND 0.133* ND ND ND WS 08 Natore sadar, Natore ND ND ND ND ND ND ND 5.24* WS 11 Burichang, Comilla ND ND 4.06* ND 8.29* ND ND ND WS 14 Sikderpara, Bandarban ND ND ND ND ND ND ND 5.08* WS 22 WS 23 Chatak, Sunamganj Rajoir, Madaripur ND ND ND ND ND ND ND ND 5.6* ND ND ND ND ND 5.04* 5.14* All samples are irrigated water samples and are measured in triplicates Concentrations in bold are those that exceed levels that are safe for humans, established by the WHO at 0.03 lg/L for Heptachlor and 2 lg/L for DDT Limit of detection (LOD): 0.01 lg/L WS Water Sample ND Not Detected * Mean value of triplicates the pesticides could have entered the country illegally and may have contributed to the DDT residues detected. Our results indicated that none of the samples were contaminated with DDD, but a sample from Burichang where agriculture was the main activity was contaminated with 4.06 lg/L of DDE (Fig. 1b). A previous study revealed that DDT, DDE and dieldrin were present in some water samples obtained from irrigated crop fields in Gaibandha, Bangladesh (Matin et al. 1998). However, ground water samples from Nayarhat in the Dhaka District of Bangladesh were free from these residues (Matin et al. 1998). Several investigators found high concentrations of DDTs in river sediments from China (Hong et al. 1995, 1999; Wu et al. 1999). The use of heptachlor is allowed in Bangladesh for specific purposes (Matin et al. 1998). This chemical was also used extensively in seed treatments and control of soil insects, such as ants. Therefore, it is not surprising that several of the water samples contained this pesticide’s residue. Furthermore, due to its highly stable structure, heptachlor can persist in the environment for decades. From our study, the water sample collected from Natore had the highest concentration (5.24 lg/L) of heptachlor (Fig. 1c), while three samples from Madaripur, Bandarban and Sunamganj contained heptachlor at concentrations of 5.14, 5.08 and 5.04 lg/L, respectively. The levels from all four sampling sites are higher than the 0.03 lg/L value recommended by the WHO to ensure drinking water quality (WHO 1996). Previous reports have shown that heptachlor and its epoxide were detected in water (Boonyatumanond et al. 2007) and agricultural soil samples (Hudak and Thapinta 2005) in Thailand. The persistent nature of the organic pollutants, such as organochlorines, is of great concern due to their bioaccumulative nature and the toxic biological effects on wildlife and humans (Tanabe et al. 2000). Elevated concentrations of organochlorines have been detected in a wide range of environmental media and aquatic biota (Iwata et al. 1993; Tanabe 2000; Tanabe et al. 2000). We did not detect any contamination from aldrin, DDD, dieldrin, endrin and lindane organochlorine pesticides in any of the water samples. It has been reported that sunlight and bacteria can change aldrin to dieldrin and that dieldrin then degrades slowly in both soil and water (ATSDR 2002). However, because both compounds are not detected in this study, it is possible that farmers in the selected study areas no longer use these pesticides. The quality of irrigated water is an important factor influencing the high-yielding crops. Irrigation water quality affects soils, crops and their management. Highquality crops can be produced only by using high-quality irrigation water and by keeping other inputs optimal (Islam and Shamsad, 2009). However, in this study, only surface water samples, and not ground water samples, were studied. It would also be interesting to compare the presence of pesticides in water samples collected from different seasons because collections during the rainy seasons tend to reflect higher levels of pesticides concentrations (Sankararamakrishnan et al. 2005). It can be concluded that there is no contamination of aldrin, DDD, dieldrin, endrin or lindane organochlorine pesticides in the locations in Bangladesh selected in this study. The absence of these organochlorine pesticide residues in this study indicates that farmers in the selected study areas of Bangladesh may no longer use these banned 123 154 pesticides. The presence of two other organochlorine pesticide residues in several regions of Bangladesh in this study indicates lapses in regulatory control that may endanger the health of the environment and humans. Therefore, tight monitoring and better regulatory controls should be adopted to control the use of these pesticides by farmers in order to prevent and reduce harmful environmental impacts. Acknowledgments We acknowledge the financial support from a research university grant (1001/PPSP/815058). References Alam MN, Das NG, Rahman MM, Malek MA (1999) Organochlorine Insecticide Residues in Water and Soil on the Meghna Dhonagoda Irrigation Project of Bangladesh. J Asiatic Soc Bang (Science) 25:135–142 APHA (1995) Standard Methods for the Examination of Water and Waste Water. Washington 19th edn, pp 1–30, 40–175 Bagchi S, Azad A, Alomgir ZC, Uddin MA, Al-Reza SM, Rahman A (2009) Quantitative analysis of pesticide residues in some pond water samples of Bangladesh. Asian J Water Environ Pollut 6:27–30 Boonyatumanond R, Wattayakorn G, Amano A, Inouchi Y, Takada H (2007) Reconstruction of pollution history of organic contaminants in the upper Gulf of Thailand by using sediment cores: First report from Tropical Asia Core (TACO) project. Mar Pollut Bull 54:554–565 Chevrier J, Eskenazi B, Holland N, Bradman A, Barr DB (2008) Effects of exposure to polychlorinated biphenyls and organochlorine pesticides on thyroid function during pregnancy. Am J Epidemiol 168:298 Chowdhury AZ, Jahan SA, Islam MN, Moniruzzaman M, Alam MK, Zaman MA, Karim N, Gan SH (2012) Occurrence of organophosphorus and carbamate pesticide residues in surface water samples from the Rangpur District of Bangladesh. Bull Environ Contam Toxicol 89:202–207 Cuadra SN, Linderholm L, Athanasiadou M, Jakobsson K (2006) Persistent organochlorine pollutants in children working at a wastedisposal site and in young females with high fish consumption in Managua, Nicaragua. AMBIO: A J Hum Environ 35:109–116 DFG (1987) Manual of Pesticide Residue Analysis, vol 1. Pesticide Commission, Weinheim, New York, pp 297–307 Environment and Social Development Organization (ESDO) Bangladesh (November 2005). POPs hotspots in Bangladesh. Accessed on 3 August 2010 123 Bull Environ Contam Toxicol (2013) 90:149–154 Hong H, Xu L, Zhang L, Chen J, Wong Y, Wan T (1995) Special guest paper: environmental fate and chemistry of organic pollutants in the sediment of Xiamen and Victoria Harbours. Mar Pollut Bull 31:229–236 Hong H, Chen W, Xu L, Wang X, Zhang L (1999) Distribution and fate of organochlorine pollutants in the Pearl River Estuary. Mar Pollut Bull 39:376–382 Hudak PF, Thapinta A (2005) Agricultural pesticides in groundwater of Kanchana Buri, Racha Buri, and Suphan Buri Province, Thailand. Bull Environ Contam Toxicol 74:631–636 Hunt DTE, Wilson AL (1986) The chemical analysis of water-general principles and techniques, 2nd edn. The Royal Society of Chemistry, Cambridge, pp 29–43 Islam M, Shamsad S (2009) Assessment of irrigation water quality of Bogra District in Bangladesh. Bang J Agric Res 34:507–608 Iwata H, Tanabe S, Sakai N, Tatsukawa R (1993) Distribution of persistent organochlorines in the oceanic air and surface seawater and the role of ocean on their global transport and fate. Environ Sci Technol 27:1080–1098 Jacobson JL, Jacobson SW (1996) Intellectual impairment in children exposed to polychlorinated biphenyls in utero. N Engl J Med 335:783–789 Matin M, Malek M, Amin M, Rahman S, Khatoon J, Rahman M, Aminuddin M, Mian A (1998) Organochlorine insecticide residues in surface and underground water from different regions of Bangladesh. Agric Ecosyst Environ 69:11–15 Sankararamakrishnan N, Kumar Sharma A, Sanghi R (2005) Organochlorine and organophosphorous pesticide residues in ground water and surface waters of Kanpur, Uttar Pradesh, India. Environ Int 31:113–120 Tanabe S (2000) Asian developing regions: persistent organic pollutants in Seas. In: Sheppard CRC (ed) Sea at the millennium: an environmental evaluation. Elsevier Science, Amsterdam, pp 447–462 Tanabe S, Prudente MS, Kan-Atireklap S, Subramanian A (2000) Mussel watch: marine pollution monitoring of butyltins and organochlorines in coastal waters of Thailand, Philippines and India. Ocean Coast Manag 43:819–839 Vighi M and Funari E (1995) Pesticide risk in groundwater, CRC WHO (1996) Guidelines for drinking-water quality: health criteria and other supporting information, vol 2, 2nd edn, pp 940–949 Wu Y, Zhang J, Zhou Q (1999) Persistent organochlorine residues in sediments from Chinese river/estuary systems. Environ Pollut 105:143–150 Zuo Y, Chen H, Deng Y (2002) Near-infrared spectroscopy applications in pharmaceutical analysis. Talanta 57:307–316