Pesticide Residues in Coastal Tropical Ecosystems: Distribution, fate and effects - Chapter 7 potx

Pesticide use in Malaysia 159Chapter 7 Pesticide use in Malaysia Trends and impacts Abdul Rani Abdullah INTRODUCTION Agriculture has always been an important sector of the Malaysian economy. Although its contribution to Malaysia’s GDP has been steadily decreasing over the last few decades (down from 33 percent in 1960 to 12.7 percent in 1996 due predominantly to an increasing emphasis on industrialization), the agricultural sector continues to grow in absolute terms (MADI, 1996; MACA, 1997). In 1985, agriculture accounted for 20.8 percent of GDP with a value of US$4.6 billion. However, in 1996, the contribution to GDP had decreased to 12.7 percent while the absolute value had increased to US$6.6 billion (MADI, 1997). Malaysia is currently one of the world’s primary exporters of natural rubber and the world’s primary exporter of palm oil. These together with cocoa, pepper, pineapple, and tobacco comprise the main crops responsible for the growth of this sector. Agriculture has also been an important base for the development of other sectors of the Malaysian economy, particularly the manufacturing sector as exemplified by the food and beverage industry. The pesticide industry is one of the most important support industries in agriculture. The economic benefits of pesticide use in producing high crop yields and the role of pesticides in the control of disease-borne pests are undeniable. Equally the adverse effects of elevated pesticide residues in water, soil, and crops to man, domestic animals, wildlife, and the environment are well recognized and documented. In tropical countries like Malaysia, crops such as rice and vegetables are particularly susceptible to the negative impacts of pesticide use (ADB, 1987). This is attributed to the often indiscriminate and intensive use of pesticides associated with these crops. The problem is exaggerated by the inadvertent destruction of the pest’s natural enemies, and the emergence of resistant pest strains, the conse- quence of which is the application of increasingly larger amounts of pesticides. Other crops, including palm oil and rubber, also require intensive use of pesticides, particularly herbicides. In addition to their use in agriculture, pesticides have also contributed to the control of insect-borne diseases. Pest control programs to improve public health © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 160 Abdul Rani Abdullah in Malaysia have been primarily directed toward the eradication of mosquitoes. Under the Malaria Eradication Program initiated in 1967, wall surfaces inside homes of malaria-infected areas were sprayed with DDT. Dengue fever was similarly brought under control by large-scale spraying programs using insecticides such as pyrethrins, malathion, and temephos (Abate). Other diseases such as typhus (carried by body lice) and dysentery (carried by flies), once rampant and greatly feared, have been either curtailed or practically eradicated by the application of pesticides in addition to other public-health related strategies. Recently, research has focused on evaluating the efficacy of alternatives to DDT and other OCs – specifically OPs, pyrazoles, and pyrethroids – or controlling disease vectors (Yap et al., 1996; Sulaiman et al., 1999; 2000). The objective of this chapter is to examine various aspects of pesticide use in Malaysia, including current trends, levels of contamination in the aquatic environ- ment, as well as impacts of pesticide use. In addition, recommendations and suggestions are put forward with respect to both mitigation measures, and essential areas of additional research. AGRICULTURE AND PESTICIDES In a relatively short period of time, Malaysia became a major producer of primary commodities and assumed a dominant world position in rubber, palm oil, and cocoa. The location of the major agricultural areas on Peninsular Malaysia is given in Figure 7.1. Currently oil palm remains the favored crop, while rubber and cocoa have undergone a decline in acreage in recent years (see Figure 7.2) (MACA 1997). In 1996, the number of hectares devoted to oil palm increased by 2.4 percent from the previous year to 2.6 M ha. Indeed, Malaysia is currently the world’s leading producer of palm oil at 53 percent of total world palm oil production in 1993 (MADI, 1996). The decrease in acreage for rubber and cocoa has been attributed to the shortage of labor as well as the conversion of land to other crops, particularly oil palm, and for commercial and residential uses. The area under rice paddy culture has also been on the decline (Figure 7.2). In order to achieve a targeted 65 percent self- sufficiency in rice, there has been an emphasis on increased crop intensity, mechanization, and varietal yield (HYV) improvements. It should also be noted that IPM has been widely promoted for rice paddies and has resulted in a reduction of incidences of pest population explosions as was frequently reported in the 1970s and early 1980s. These incidences particularly related to severe outbreaks of the brown planthopper Nilaparvata lugens Stål (Homóptera: Delphacidae) and the white- backed planthopper Sogatella furcifera Horváth (Homóptera: Delphacidae) (MACA, 1997). Although the importance of agriculture is declining, it continues to play an important role in the development strategy of Malaysia. Agriculture’s continued © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts Pesticide use in Malaysia 161 importance lies in its contribution to the rural economy and to its link with other sectors of the economy by providing the raw materials for manufacturing and agronomic-based industries. A National Agricultural Policy (NAP, 1984) was promulgated in 1984 to serve as a guideline for Malaysia’s agricultural development up to the year 2000. A few years later, the policy was redefined as the NAP, 1992 to 2010 to emphasize various strategies such as the optimization of resource use, the development of related agro-based industries, and the enhancement of research and development activities. The success of the agriculture sector in Malaysia was achieved by the introduc- tion of sound and effective agricultural policies, coupled with the application of modern technologies. NAP (1984) was aimed toward greater agricultural produc- tivity, emphasizing higher-value crops such as oil palm, cocoa, vegetables, fruits, and flowers. Modern practices of large-scale continuous cropping of individual Figure 7.1 The location of major agricultural areas by crop in Peninsular Malaysia (Yeop, et al. 1982)                                      Rubber               Palm oil        Padi         Coconut      Mixed crops © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 162 Abdul Rani Abdullah crops and the use of high-yielding strains were also encouraged. Many of the benefits obtained from the adoption of monoculture technology and the use of HYV(s) are dependent on effective plant protection strategies. Monocultures tend to encourage rampant population growth of pest species by providing ideal conditions for their development and reproduction. Crop losses have also resulted due to disease and pests encouraged by large-scale planting and genetic uniformity of the crop, a consequence of using a limited range of HYV(s). Large-scale continuous cropping of individual crops also tends to encourage the growth of pest species by providing the necessary conditions for their development. Hence, improved management practices, including more cost-effective pest control strategies, have been introduced. The majority of the pesticides used in Malaysia are applied in the rubber, oil palm, and rice sectors of agriculture. As can be seen in Table 7.1, herbicides account for 75 percent of the total pesticide market, followed by insecticides (16 percent), fungicides (5 percent), and rodenticides (4 percent) (MACA, 1997). Table 7.2 lists Figure 7.2 Change in the area planted in oil palm, rubber, cocoa, and rice in Malyasia for the years 1980, 1990, and 1995 (MACA, 1997) 0 500 1000 1500 2000 2500 Area (ha x 1000) 1980 1990 1995 Year Cocoa Rice Oil p alm Rubber Table 7.1 Estimate of the pesticide market a in Malaysia (US$ M) b Pesticide class 1990 1991 1992 1993 1994 1995 1996 Herbicides 104.5 92 84 80 80.4 88 90.8 Insecticides 17.1 16 16.4 15.6 16.4 17.2 18.8 Fungicides 5.8 5.2 5.2 5.2 5.6 6 6.4 Rodenticides 4.2 4 4.8 4 4.4 4.4 4.4 Total 131.6 117.2 110.4 104.8 106.8 115.6 120.4 Notes: a End-user value at a constant exchange rate of US$1 = RM2.5. b Adapted from MACA, 1996; 1997. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts Pesticide use in Malaysia 163 some examples of commonly applied pesticides in oil palm, rubber, cocoa, and rice. Herbicides used in Malaysia are predominantly in the form of aqueous concentrates while the majority of insecticides and fungicides used are in the forms of emulsifiable concentrates and wettable powders respectively (Abdullah, 1993). The use of herbicides has been and will continue to be an important aspect of the crop protection strategy in Malaysia as long as a labor shortage makes manual Table 7.2 Commonly used pesticides in oil palm, rubber, cocoa, and rice in Malaysia a Crop Pesticide class Herbicide Insecticide Fungicide Oil palm 2,4-D dimethylamine Carbofuran Captan Diuron Chlorpyrifos Chlorothalonil DSMA (disodium Cypermethrin Maneb methylarsonate) + Endosulfan Thiram diuron + dicamba Methamidophos Fluazifop-butyl Monocrotophos Glufosinate ammonium Glyphosate Metsulfuron methyl Paraquat Quinclorac, (a quinolinecarboxylic acid herbicide) Rubber Same as for oil palm Chlorpyrifos Hexaconazole, Cypermethrin (a conazole Dicofol fungicide) Dimethoate Propineb Tridemorph Chlorothalonil Cocoa Fluroxypyr methyl α-cypermethrin Captafol heptyl ester, (a Cypermethrin + Copper pyridyloxyacetic acid chlorpyrifos oxychloride herbicide) Deltamethrin Hexaconazole Glufosinate ammonium Lindane Triadimenol Glyphosate Methamidophos Oxyfluorfen Sodium chlorate Rice Propanil Acephate Benomyl Quinclorac α-cypermethrin Carbendazim 2,4-D butyl ester BPMC [2-(1-methyl- Thiram Bentazone propyl)phenyl Flutolanil, (a Metsulfuron methyl methylcarbamate] benzanilide Oxadiazon Carbaryl fungicide) Carbofuran Mancozeb Endosulfan Lindane Diazinon Note: a Derived from MADI, 1996. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 164 Abdul Rani Abdullah weeding uneconomical. Most herbicide is applied on rubber and palm oil planta- tions. While older herbicides, e.g. paraquat, glyphosate, glufosinate-ammonium, and 2,4-D, represent the bulk of herbicides used in Malaysia, there has also been an increase in popularity for the use of newer chemicals, e.g. metsulfuron methyl, which require only low concentrations to be effective (MADI, 1996). It is also noteworthy that Malaysia exports a considerable quantity of pesticides, particularly herbicides. In 1993, herbicides worth US$10.8 million, e.g. paraquat, 2,4-D amine, sodium chlorate, glyphosate, diuron, monuron, and linuron, were exported primarily to other countries in the region (MADI, 1997). The use of insecticides, predominantly in vegetable production, is characterized by the wide variety of available chemicals. As with herbicides, newer, more biologically active and environmentally friendly chemicals are increasingly popular. These chemicals tend to be more costly but are effective at lower concentrations. Fungicides are for the most part imported because their consumption is low, being used mainly in vegetable, fruit, and flower production. The most common method of applying pesticides in Malaysia is spraying the pesticide solution onto crops with a knapsack sprayer. This application technique has been proven to be inefficient as only about 20 percent of the spray reaches the plants, and less than 1 percent of the chemical contributes to pest control, resulting in wastage and contamination of the environment (MADI 1996). This is attributable to the variable size of the droplets, which tend to coalesce and run off the leaf surface, produced by such sprayers. The fine mist generated by these sprayers also tends to evaporate before reaching the plants. Controlled droplet application (CDA) technology has been introduced to increase the efficacy of pesticides by restricting the droplet size to an optimum range. In Malaysia the use of CDA has not been widespread due mainly to the higher cost of the sprayer but also to higher opera- tional and maintenance costs. However, the use of CDA has become quite common on the larger oil palm plantations (MADI, 1996). In recent years there has been a gradual decrease in the growth of the pesticide market in Malaysia from an annual increase of 9 percent in 1992 to 3 percent in 1996 (estimated at end-user level) (MADI, 1997). The decreasing trend in pesticide use has been attributed to the introduction of improved products with greater efficacy and selectivity, more judicious application of the pesticides, and the development of biological control and integrated pest management strategies. Some examples of recently introduced pesticides include cyhalofop butyl (an aryloxy- phenoxypropionic herbicide), tralomethrin (a pyrethroid ester insecticide), and acetamiprid (a pyridine insecticide). These chemicals exhibit substantial reduction in dosage rates and therefore smaller amounts are applied to treat the same area of cultivated land. Improved pest management practices have also contributed to this trend, including such specialized biocontrol techniques as arthropod-dependent (ant) protection from pests in cashew nut Anacardium occidentale (Anacardiaceae) production (Rickson and Rickson, 1998) and parasitoid control of the diamondback moth Plutella xylotella L. (Lepidoptera: Plutellidae) in vegetable production (Verkerk and Wright, 1997). New pesticide chemistry, biocontrol techniques, and IPM © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts Pesticide use in Malaysia 165 procedures all contribute to the management of developed/developing resistance in pest species because of improperly or excessively used pesticides. Pesticide resistance studies in Malaysia have most often implicated phase I microsomal monoxygenases and (or) esterases in the development of resistance to such diverse pesticides as the carbamates propoxur and bendiocarb, the OP chlorpyrifos, the pyrethroids cypermethrin and permethrin, the antibiotic pesticide abamectin, the chitin synthesis inhibitor teflubenzuron, and the biological insecticide Bt (Lee et al., 1996; Iqbal and Wright, 1997; Verkerk and Wright 1997). However, Iqbal and Wright (1997) did find some evidence for the involvement of phase II glutathione- S-transferases in decreasing the toxicity of abamectin to P. xylostella. Resistance management strategies must account for the development of cross-resistance, the use and timing of synergists, and the management of parasitoids and other bio- control species. The pesticide industry in Malaysia is made up of about 140 companies – both multinational and local companies – that are involved in manufacturing, formu- lating, or trading activities (MACA, 1997). The majority of pesticides are imported as technical materials, which are then blended, diluted, or formulated. However, in recent years an increasing variety of pesticides are being manufactured in Malaysia. These include herbicides such as paraquat, sodium chlorate, dalapon, and glyphosate. At present, the quantity of wastes generated by these industries is rather small and generally manageable. Current waste treatment systems include those based on chemical degradation (alkaline hydrolysis, particularly for OPs) and those using oxidation ponds (Samad, 1991). In addition to chemical pesticides, biological pesticides – best exemplified by the bacterium Bacillus thuringiensis (Berliner) (BT) – have been introduced into the Malaysian pesticide market. BT’s specificity and versatility, in that different variants can be developed for different pest species, are an important contribution in the promotion of environmentally friendly and sustainable agricultural production. The pesticide industry is expected to continue to be an important component of the agriculture sector in Malaysia. Pesticides will continue to provide a reliable and cost-effective solution to pest and diseases problems. As the number of hectares of arable land is not expected to increase in the future – indeed, land conversions to other non-agricultural uses have been taking place – the focus in agriculture has been on increasing crop intensity and on yield improvements. Hence, to meet the increasing demands of a growing population, pesticides will continue to make an important contribution to increasing yields and to the reduction of post-harvest losses. PESTICIDE REGULATORY POLICIES For many years, pesticide use in Malaysia was controlled by the Ministry of Health under the Poisons Ordinance, 1952 and the Poison List Order, 1970 under which certain highly toxic chemicals are banned from import or manufacture. A Voluntary © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 166 Abdul Rani Abdullah Registration Scheme for pesticides was introduced in the 1960s and 1970s but was deemed to be unsatisfactory due to poor and inadequate response by the pesticide industry. This led to the introduction of specific legislative acts governing pesticide use in Malaysia. At present, the use of pesticides in Malaysia is governed by the Pesticides Act of 1974, which regulates the importation, manufacture, distribution, sale, and use of pesticides in Malaysia. The Act came into force on 1 October 1976 and is administered by the Pesticide Board of the Department of Agriculture. The Act requires that all pesticides be registered. Registration is implemented under the Pesticide (Registration) Regulations, 1976 (Pesticides Board Malaysia, 1991). Data requirements are essentially in accordance with FAO guidelines. The information required to be submitted with the application for registration of new pesticides includes the physicochemical properties of the chemical, its efficacy, storage stability, toxicological data, residue data, known environmental impacts, and a declaration that the pesticide has been approved for use in other countries that practice an acceptable registration procedure. A proposal for a label for the pesticide is also required based largely on FAO Guidelines on Good Labeling Practices for Pesticides (FAO, 1995). The registration is valid for five years after which each registered pesticide is reassessed for its continued use. In this way, several pesticides have either been deregistered, e.g. aldrin and dieldrin, or their use restricted following reassessment, e.g. HCH and endosulfan. This procedure takes into consideration safer alternatives and reported abuses among other factors. The use of pesticides deemed to be highly toxic is further governed by the Pesticide (Highly Toxic Pesticides) Regulations of 1996 – particularly with respect to specific handling restrictions – ensuring that workers handling these chemicals do so with the utmost care. Employers are required to provide adequate training to workers, who must also be medically fit. Workers are only permitted to work a maximum eight hours per day. Employers are further required to maintain strict records detailing the number of hours worked, the type and amount of pesticide used, and the method of application. Their workers are required to wear proper protective clothing and complete an annual medical examination. Furthermore, these regulations dictate that, in the case of female workers, only those who are not pregnant or lactating are permitted to handle pesticides. Other requirements include safe and proper storage of the chemicals and safe disposal of empty containers (Pesticides Board Malaysia, 1996). Handling pesticides such as paraquat, monocrotophos, and calcium cyanide is subject to these regulations. The handling of other pesticides not included in this particular list is not subject to the rigorous set of conditions stipulated in the Pesticide (Highly Toxic Pesticides) Regulations, 1996 but is, of course, required to comply with the Pesticide Act, 1974. Pesticide residues in food are controlled by The Food Regulations Act of 1985, which is enforced by the Ministry of Health. MRL(s) for pesticide residues are stipulated in this Act. The Act also provides for punitive action against those who misuse pesticides and by their actions cause unacceptable residue levels in food. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts Pesticide use in Malaysia 167 Pesticide use in Malaysia is also subject to the Environmental Quality (Scheduled Wastes) Regulations, 1987. The objectives of these regulations are to control and manage the generation, storage, transportation, recycling, treatment or destruction, and disposal of toxic and hazardous wastes. Malaysia began active environmental management with enactment of the Environmental Quality Act, 1974 and the creation of the Department of the Environment in 1976 (Abdullah, 1995). The Environmental Quality Act was amended in 1985 to include submission of Environmental Impact Assessment (EIA) reports to the Department of the Environment for proposed development projects, thus moving the country toward a proactive, preventive strategy of environmental management. EIAs, which became mandatory in 1988, are used to predict potential environmental impacts from the proposed development. There- after, mitigation measures can be identified and prescribed to minimize the predicted impacts. The Department of the Environment also regularly monitors air and water quality throughout the country. To monitor river water quality, samples are collected from 116 major rivers at 892 monitoring stations and, to assess marine water quality, there are an additional 229 sampling stations in coastal and estuarine areas (Abdullah, 1995). The majority of analyses for river and marine samples are conducted in laboratories of the Department of Chemistry under the Ministry of Science, Technology, and the Environment (Abdullah, 1995). Currently, there is no national or regional monitoring program designed to identify and measure pesticide residues in the environment beyond those tasked with evaluating possible risk to humans. PESTICIDE RESIDUES IN THE AQUATIC ENVIRONMENT Contamination of the environment by pesticides arises primarily from their application. Surface water contamination can occur as a result of spray drift from aerial spraying or runoff from agricultural areas as a consequence of rain, and to a lesser extent, leaching from the soil. Hence, runoff water contains dissolved pesticides as well as chemicals sorbed onto particulate matter. Pesticide residues can also be transported sorbed on airborne particles and then washed into the aquatic environment by rainfall. Pesticides applied on fields have been known to volatilize and be deposited in areas far removed from the point of application. Volatile pesticides have been observed to be more rapidly lost in tropical agro- ecosystems because of the high temperatures associated with this region. Several studies involving volatile OC insecticides such as DDT and HCH have shown volatilization to be a major route of dissipation of these chemicals from tropical agro-ecosystems and other tropical environments (Abdullah et al., 1997). Ultimately the ocean acts as the final reservoir for these chemicals. In addition to surface water, groundwater can also be contaminated by pesticide residues as a result of leaching from the soil and the inherent interaction between © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 168 Abdul Rani Abdullah groundwater and contaminated surface water. Contamination of the environment by pesticides arises not only from their application but also from accidental or intentional discharges of pesticides and pesticide wastes and rinses from mixing areas (on the farm) and from manufacturing plants. There is at present no national or regional monitoring program designed to investigate pesticide residues in the environment, apart from those intended to evaluate possible risk to humans. However, over the years some data have been accumulated from studies conducted by various groups and researchers. Table 7.3 provides an indication of the extent of contamination by OC pesticides in both biotic and abiotic components of the freshwater environment of Malaysia. OCs are of particular concern due to their persistent nature, and their bio-accumulative and toxic properties. OC pesticide residues are commonly detected in the aquatic environment. Pesticides, which have been banned or whose use has been restricted, e.g. dieldrin, endrin, and DDT, continue to be detected in the environment due to their persistent character. In a recent study by Tan et al. (1991), DDE, DDT, and heptachlor were found in samples of water from almost every river surveyed in Peninsular Malaysia. Endosulfan, an insecticide with a well-documented piscidal activity, was also commonly detected. As to be expected, higher levels of pesticide residues were observed in the vicinity of agricultural land. HCH, heptachlor, aldrin, and endosulfan were detected in sediments in a recent survey conducted in the vicinity of a rice growing area (Tan and Vijayaletchumy, 1994). Significant levels of both HCH and endosulfan were due to current usage of these chemicals in rice fields. In general, there appears to be a decreasing trend in the levels of OC pesticides detected in the Malaysian aquatic environment. This can be seen when a com- parison is made between earlier studies and more recent studies (see Table 7.3) of Malaysia’s freshwater environment. Additionally, this trend is apparent in relation to similar studies conducted in India where OC insecticides, in particular HCH and DDT, have been the major pesticides for years. Surveys in 1982 in Tanjong Karang (Table 7.3) for example, showed levels of 600 ng L –1 of α-HCH and γ- HCH in water. These levels are comparable to similar studies conducted in India (Ramesh et al., 1990). However, a recent survey by Tan et al. (1991) showed substan- tially less contamination. This encouraging trend can be attributed to several factors, including the increasingly popular use of less persistent OP and carbamate pesticides in favor of the OC class. Educational programs in the safe and effective use of these chemicals conducted by the pesticide industry and the Department of Agriculture and directed toward end users and suppliers of pesticides have also contributed to the observed trend. The marine environment, in particular near-shore coastal waters, has also been observed to be contaminated by OC pesticide residues. The majority of Malaysia’s agricultural land is located in the vicinity of the western coastline of Peninsular Malaysia (Figure 7.1). Hence, agricultural runoff and spray drift allow the deposition of applied pesticides into near-shore coastal waters. In Malaysia, surveys conducted to measure pesticide residues in the marine environment have been © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts [...].. .Pesticide use in Malaysia 169 Table 7. 3 OC pesticide residues in the aquatic environment of Malaysia Location Survey year Matrix Pesticide Concentration References (ng mL–1or ng g–1) Krian River Basin, Perak 1981 Water Dieldrin β-HCH γ-HCH Aldrin Dieldrin β-HCH γ-HCH Aldrin Dieldrin α-Chlordane β-HCH Aldrin α-HCH γ-HCH α-HCH γ-HCH α-endosulfan β-endosulfan α-HCH Dieldrin DDT α-endosulfan β-endosulfan... ND 180.9 0.222–3.01 1.23 27. 50–66.46 1.46 7. 41 0.05 0.24 Jothy et al., 1983 Jeram, Selangor DDT Lindane Dieldrin DDT γ-HCH γ-HCH γ-HCH γ-HCH Dieldrin Dieldrin Dieldrin Dieldrin α-HCH β-HCH γ-HCH Dieldrin DDD DDE DDT α & β-endosulfan Endosulfan sulfate Lindane Lindane DDT Lindane DDT α-endosulfan Aldrin Various locations in the coastal waters off the Malay Peninsular Penang Mussels (Perna vendis) Cockles... Stephen J Klaine, Fernando P Carvalho, Damia Barcelo and Jan Everaarts Pesticide use in Malaysia 175 Table 7. 7 Area used for aquaculture in Malaysia in 1993a Type of aquaculture Area (ha) Fresh water fish culture in pond and disused mining pools Cockle culture in mudflats Penaeid prawn culture in brackish water ponds Marine finfish in floating net cages in coastal water Freshwater finfish in floating net... as shipping and land-based activities The latter represent non-point sources and © 2003 Milton D Taylor, Stephen J Klaine, Fernando P Carvalho, Damia Barcelo and Jan Everaarts 174 Abdul Rani Abdullah Table 7. 6 Bioaccumulation of insecticides in paddy field fish in Malaysia Insecticide Concentration (ppb) Fish α-HCH β-HCH α-Endosulfan β-Endosulfan 0.05 0.1 11.0 6.0 Reference 85 239 424 275 Soon and Hock,... Table 7. 6 illustrates the bioaccumulation of HCH and endosulfan in paddy-field fish in Malaysia Bioconcentration factors for α-endosulfan and lindane were 424 and 239, respectively (Soon and Hock, 19 87) Pesticides have been implicated in the decline of fish production on agricultural land, in particular paddy-fields (Yunus and Lim, 1 971 ; Alabaster, 1986) In Indonesia where agricultural practices and. .. and Jan Everaarts Pesticide use in Malaysia 179 Rohani, I., Chan, S.M and Ismail, I 1992 Organochlorine pesticide and PCBs residues in some Malaysian shellfish In: Proc Nat Seminar on Pesticides in the Malaysian Environment held 27 February 1992 in Kuala Lumpur, Malaysia Malaysia Department of Agriculture, pp 27 33 Samad, A.H 1991 Handling, storage and disposal of pesticides and pesticide wastes J... contamination is due predominantly to application in the field, an extensive program of education and public awareness on the proper uses of pesticides needs to be continued, improved, and reinforced to minimize the indiscriminate and irresponsible use of pesticides and to reflect advances in pesticide science As far as OC insecticides are concerned, lindane and endosulfan are the only two remaining... Bano, N., Swennen, C and Hillebrand, M.T.J 1991 Cyclic chlorinated hydrocarbons in benthic invertebrates from three coastal areas in Thailand and Malaysia J Sci Soc Thailand 17: 31–49 FAO 1995 Guidelines on Good Labeling Practices for Pesticides Rome: FAO Gill, S.S 1982 Pesticides and the environment In: Proc Symp on the Malaysian Environment in Crisis held 18–19 April 1981 in Pulau Pinang, Malaysia Penang,... determining pesticide residues in seafood The results of some of these surveys are given in Table 7. 4 OC pesticides in marine biota have been detected since the first surveys, conducted in the mid-1 970 s by the Fisheries Research Institute The study on OC residues in fish and shellfish from the coastal waters off the Straits of Malacca by Jothy et al (1983) is probably the earliest report on OC pesticide. .. located in coastal areas, comprise freshwater and marine fish, prawn, cockles, mussels, and oysters (Table 7. 7) (MADI, 1996) Although aquaculture is a relatively young industry in Malaysia – comprising approximately 10 percent of the net income from marine fishing activities in 1993 – it is of increasing importance because of its rapid growth Aquaculture production increased by 100 percent in 1993 . culture in pond and disused mining pools 5 ,75 4 Cockle culture in mudflats 5,041 Penaeid prawn culture in brackish water ponds 1, 878 Marine finfish in floating net cages in coastal water 671 b Freshwater. 2.8– 17. 1 β-HCH 3.3–8.2 Aldrin 0.3–1.1 Tanjong Karang, 1982 Water α-HCH 0.5 Soon and Hock, Selangor γ-HCH 0.1 19 87 Rice-field α-HCH 18–58 fish γ-HCH 10–100 α-endosulfan 5130 β-endosulfan 170 0 Penang. Dieldrin 0.2–0.5 Meier et al., 1983 Basin, Perak β-HCH 0.1–0.9 γ-HCH 0.1–0.6 Aldrin 0.1–1.8 Sediment Dieldrin 0.8–4 .7 β-HCH 0.6–8.0 γ-HCH 0.4–0.8 Aldrin 0.1 Rice-field Dieldrin 6.6–2.49 fish α-Chlordane