Sri Lanka

by J.A. Sumith

Executive Summary

Pest management in Sri Lanka is mostly pesticide dependent and the annual imports of pesticides cost around 0.1 percent of Gross Domestic Production in 2002. Sri Lanka has successfully phased out a number of hazardous pesticides including all the WHO hazard Class 1 pesticides and persistent pesticides from usage. The currently recommended pesticides are less toxic and least persistent than the earlier pesticides. Safer alternatives are available for the spectrum of pests controlled by POP/PIC pesticides. The stocks of outdated pesticides are quite significant and hence disposal is a serious issue which needs immediate attention. Although persistent pesticides were prohibited from use in agriculture and from public health more than two decades ago, traces of some pesticides and its derivatives have been detected in some environmental compartments and this needs further investigation. There is limited information available on the residues of these chemicals in groundwater and surface water bodies, which are found in large numbers in agriculture areas. Awareness on pesticide related issues, concerns and required remedial measures are alarmingly poor among most of the sectors in the society.

As the regulatory authority responsible for proper management of pesticides in the country, Office of the Registrar of Pesticides has to depend on certification of product quality by the foreign manufacturer, but the authority is not adequately equipped to verify the claims. Cooperation received from the Customs Department in controlling illegal imports and pesticide industry in safe handling of pesticides, are very encouraging. However, certain improvements are needed in custom classification procedure to ensure prevention of possible imports through improper declarations. Incidences of pesticide related accidents are very high in Sri Lanka while most of the incidents are for suicidal intent. On the other hand, environmental damage due to pesticides has not been adequately studied.

Sri Lanka strongly advocates adoption of IPM technology to control pests, thereby, reducing the over dependence on pesticides. This in the long run helps to minimize pesticide-related hazards, in addition to ecological benefits.

Introduction

Country profile

The economy of Sri Lanka is mainly agriculture based. It has two sectors namely, domestic and plantation sector. The domestic sector, which forms the dominant part of agriculture, accounts for 1.7 million farm families in a population of around 19 million. Both sectors jointly contribute 20 percent to Gross Domestic Product (GDP) and 34 percent to employment (Central Bank Report, 2002). Compared with countries of South Asia, Sri Lanka has a high population density of 0.35 ha per person. Out of total land area of 6.5 million ha, only about 5.5 million ha are arable. Thus, it is vital that the production efficiency in agriculture sector be improved both in production and post harvest aspects.

In management of pests, the plantation sector approach in a more organized manner whereas, in the domestic sector it is more complicated due to large number of farmers, crops and the pests involved. Agriculture is the biggest user of pesticides in Sri Lanka. The extents under different agricultural crops are given below; Rice (685 625 ha), Fruit crops (99 727 ha), Other agricultural crops (131 220 ha), and Plantation crops (694 674 ha) (AgStat, 2004).

Trends in pesticide use and trade

In Sri Lanka, the pest control is mostly dependent on the use of synthetic pesticides. Pesticides are imported to the country as ready-to-use products in handy packages, bulk formulations or technical materials for local formulations. By 2003 the CIF value of the country's pesticide requirement was 19.6 million US$ and of this 2.72 million US$ was allocated for the import of technical material for local formulation. Of this 16.78 million US$ was allowed for direct import of formulated products (Table 1).

Table 1. Foreign exchange spent for import of pesticides-2003

Source: Pesticide Statistics for the Year 2003, Office of the Registrar of Pesticides.

At present, over 1 000 brand pesticide products are registered (approximately 55 insecticide active ingredients, 32 fungicide active ingredients and 30 weedicide active ingredients) which are marketed and/or handled by more than 120 private sector organizations. The continuous dependence on use of pesticides had brought a dramatic increase of imports since the enactment of the Pesticide Law in the country from 2 309 metric tons in 1980 to 5 120 metric tons in 2003. Total annual agricultural pesticide consumption was estimated as 1 696 metric tons of active ingredients at a cost of 49 million US$ in 2000 (Table 2).

According to FAO (1997), Sri Lanka ranks very high in the Asia Pacific Region with regard to pesticide related health hazards. Annually the total number of pesticide accidents in Sri Lanka is around 20 000 of which 1 600 are fatal with 70 percent of this being suicidal attempts.

Regulatory control measures

Prior to 1962, pesticides were more or less freely imported into the country. With the changing import policies in late 70's, pesticides were imported on open general licenses even including prohibited products such as DDT and endrin by unscrupulous traders. With the gradual involvement by the Department of Agriculture, recognizing the need to exercise control over the use of pesticides since early 60's, an effective regulatory mechanism was brought into action in 1983 through the Control of Pesticides Act No. 33 of 1980. It makes provisions to regulate the import, formulation, packing, labeling, storage, transport, sale and use of pesticides. Thus, it is evident that the law applies to all pesticides, whether the end use is in the fields of agriculture or public health, or whether the products are to be used in the household, veterinary or the industry.

Table 2. Pesticide consumption in Sri Lanka 1995-2000

Note: Pesticide classifi cation is based on the "List of Major Plant Protection Products", FAO Statistics Division, Rome, Italy.

* Values are based on the consumption of chlordane and endosulfan.

** Values are based on the consumption of endosulfan only.

The Registrar of Pesticides is the national authority for implementing the laws and regulations under the Control of Pesticides Act No. 33 of 1980 and hence conformation to international conventions in relation to pesticides such as POP, PIC, etc. which would be carried out as a routine measure. Pesticides Technical and Advisory Committee (PeTAC) is the statutory body comprising of 15 members with the representation of government agencies who gives advice on policy and technical matters to the Registrar of Pesticides. The Registrar of Pesticides is further assisted in formal and informal manner with expertise available in the Department of Agriculture and other government institutions (Figure 1). The basis of regulation is the compulsory registration of all pesticide material. The post registration activities are an inherent part of Sections 20-22 of the Control of Pesticides Act, which enables the regulatory process to safeguard food quality, human health and the environment against pesticides. These activities would enable a full evaluation of risks associated with the use of pesticides in the field and to take necessary regulatory action.

Figure 1. Administration structure and staff composition of the Office of the Registrar of Pesticides

No pesticide may be imported in to the country without registration and the appropriate licence authorizing importation of pesticides issued by the Registrar of Pesticides and only to registered importers. Processing of an import license is based on compulsory pre-registration, quality, source identification and regulatory policies with special consideration on banned and restricted pesticides. Legal provisions are provided by the Control of Pesticides (Amendment) Act No. 06 of 1994 for licensing of traders, appointment of authorized officers, specifying the functions and powers to seize pesticides in outlets conducting activities contrary to the legal provisions and regulations. All traders engaged in the storing, selling or offering for sale any pesticides are required to obtain a certification for sale from an Authorized Officer. As a mandatory requirement for the issuance of a licence, applicants for dealership are required to undergo one-day training on the principles of pesticides safety, identification of pesticides and awareness on the registration system conducted by the officers of the Office of the Registrar of Pesticides. Awareness and legal binding thus created would expect to minimize unscrupulous trade practices and thereby adverse impacts due to pesticides.

Sri Lanka has a national policy implemented in 1995 that no pesticide formulation of WHO hazard class Ia/Ib are marketed for regular pest control purposes in agriculture. Accordingly, some of the formulations of insecticides such as endosulfan, chlorpyrifos, carbosulfan, and quinalphos which are falling into the WHO hazard class Ib have been banned, which are considered to be the most dangerous with high acute toxicity and also the pesticides with longer persistence in the environments. To this second category falls the POP group of pesticides. All pesticides should be subjected to a comprehensive bio-efficacy testing procedure prior to submission of application for registration. The registration package should consist of original reports on all related chemical, physical, biological, toxicological and environmental data. For commodity products the reports are required from accredited laboratories with GLP compliance. No "me too" registrations are allowed thus registered products are constantly subjected to latest international developments either at the time of re-registration after every three years or as and when necessary. However, most of the implementation strategies are not up to expectations, due to the lack of resources like manpower, laboratory facilities, equipment, mobility, etc.

Import control

An established working mechanism exists where pesticides are concerned under the specific HS coding system. Should any pesticide be prohibited for import unless with forged declarations, there is no possibility that they would be infiltrated through the Customs who work closely with the Registrar of Pesticides in regulating pesticide imports.

A committee established under the Ministry of Science and Technology in March 2001 to implement the recommendations made by the Presidential Committee on "Chemicals Used in Agriculture, Health and Other Sectors" appointed a sub committee of which the Registrar of Pesticides was the convener, to create sub-headings in the Custom Tariff Guide under relevant HS Codes other than the ones already brought under license in order to identify all pesticides that are banned/restricted or registered for use in the country for regulatory purposes.

Sri Lanka is a member nation of the United Nations and has agreed to support the International Code of Conduct on the Distribution and Use of Pesticides, which outlines the overall responsibility of member governments in participation of the pesticide Industry to allocate high priority and adequate resources for pesticide management. Pesticide Association of Sri Lanka (Presently called as CropLife-Sri Lanka) was established in 1981 as an integrating body of pesticide traders in Sri Lanka. It integrates firms, companies, corporations and individuals in importation, distribution, formulation, and marketing of pesticides. The contribution shown by the Association towards the observance of the International Code of Conduct (FAO, 1990), especially in extending the message of safety in the use of pesticides is more convincing. Currently, self-monitoring in the areas of maintaining factory standards in pesticide formulation, re-packing and quality control of locally formulated pesticides is warranted. However, the challenge will be how to achieve compliance with local laws and regulations in an efficient way, which may involve working corporately with members, non-members, other state agencies and the pesticide regulatory authority.

A. Pest and pesticide management

Replacement of all persistent pesticides with other chemical alternatives in agriculture, public health vector control, industrial uses such as wood preservation and termite control have been successfully implemented in Sri Lanka. For persistent pesticides, the availability of safer alternatives has made them redundant in chemical pest control. In replacing the persistent pesticides, the alternatives were recommended on the basis of pests, not on the basis of the chemical, and hence in certain cases there were more than one pesticide available to cover the spectrum of pests.

Myths in the farming communities regarding chemical pest control, lack of proper awareness of pesticides and irresponsible promotion of products in the field by suppliers/dealers have contributed towards number of incorrect practices. Selection of chemicals for pest problems, timing, frequency and dosage of application are some of the most frequent indiscriminate uses carried out by farmers. This would result in poor yield, high input cost and low quality produce.

Therefore, farmers should be properly educated through comprehensive campaigns designed, based upon technical as well as socio-economic aspects of the farming community. Integrated Pest Management (IPM), the internationally acclaimed solution to indiscriminate use of pesticides, has been declared as one of the government policies in sustainable development of agriculture. The government of Sri Lanka has a long-standing commitment to IPM. In the policy statement (1994) of the President of Sri Lanka it was declared that "the dependency on chemical fertilizers and agro-chemicals will be progressively reduced through soil fertility improvement measures, adoption of integrated pest management and other agronomic practices".

Successes of Integrated Pest Management

Sri Lanka has a very successful IPM program in rice spread all over the country, initially sponsored by FAO from 1984-2001. The success was made possible by right policy decisions of the governments with regard to pest management coupled with the availability of relevant technologies and institutional arrangements which has facilitated the efforts of control on pesticide use (Administration Report, Department of Agriculture, 2000, 2002).

The success of IPM program in rice over the last several years has resulted in the demand for IPM for other field crops as well. During 1996 yala season IPM was adopted for chili crop that consumes extremely high quantities of pesticides. The Farmer Field Schools (FFS) conducted with a group of chili farmers were able to change their attitudes on pesticide use and reduced the pesticide usage by about 75 percent (Administration Report, Department of Agriculture, 2000). This has motivated agriculture research for further studies on IPM for chili and other crops as well. Most farmers in the central region of the country were adopting rice/vegetable mixed cropping pattern with rice being the minor crop. Since these farmers seldom apply any insecticide on rice the positive gain by IPM was not evident. Unlike in rice, vegetable farmers apply large quantities of pesticides to their vegetable crops. The experience gained by them through rice/FFS on ecosystem analysis and identification of pests and their relationship with natural enemies have made a considerable change in their thinking about pesticide usage in the growing of vegetables. These preliminary observations confirmed that there is much scope for IPM in vegetable production. Expansion of IPM on vegetables is further explored by the Department of Agriculture with the technical backup given to the provincial extension service to conduct IPM demonstrations in farmer fields on tomato and leafy vegetables (Administration Report, Department of Agriculture, 2000).

It has been observed that if a promotional package is offered with alternatives to the use of pesticides such as IPM, we can anticipate a reduction in the use of pesticides or a deviation from the trend in chemical dependant pest control (Sumith, 2002). The significance reduction in the use of fenobucarb (BPMC) in 1995 compared to that of 1990 (Figure 2) may be a result of intensive rice IPM program conducted by the Department of Agriculture where fenobucarb is mainly used in rice Brown Plant Hopper (BPH) control.

The overall impact of IPM revealed that (1) Reduction in insecticide use: IPM farmers use an average of 0.48 insecticide applications against 2.27 applications by non-IPM farmers per season in all 8 provinces; (2) Yields: IPM farmers obtain 23 percent higher yields than non-IPM farmers on the average in the experimental fields; (3) Durability of FFS training: IPM farmers still continue to use on an average less than 0.5 times insecticide applications/season for their crops even 5-8 seasons after training; (4) Community action: FFS training has strengthened group action thus motivating farmers to go back to traditional systems like "aththam" (mutual help) in labor intensive operations; (5) Farmers as leaders: FFS training has integrated farmers to become IPM trainers and take the responsibility of training other farmers in the village; and (6) Benefits: Obtain higher profits due to cost reduction plus increased yields; become experts in crop management; enjoy better health due to minimal exposure to hazardous chemicals (Hector Senarath, IPM National Expert, IPM/FAO Project, personal communication).

(Source: Sumith, J.A. (2002). Pesticide Management in Sri Lanka: Implementation Issues and Past Experience. Economic Review: November/December 2002, p. 23-31.)

Figure 2. Annual consumption of insecticides (mt) in 1995 and 1990

In the mean time, the national pesticide policies in Sri Lanka are also geared towards supporting IPM in crop production. Restriction of highly hazardous WHO class Ia/Ib pesticides only for certified applications, total banning of all class Ia/Ib pesticides from retail use, thorough and intensive screening at research level only the pesticides having narrow activity or less effects on natural enemies and pilot scale testing before registration, and promotion of bio-pesticides are some of the supportive roles given through the implementation of the Control of Pesticides Act.

In collaboration with the Health Ministry (Anti-Malaria Officers) and International Water Management Institute (IWMI), preliminary studies on integration of disease-vector management with community IPM in rice has been initiated by the Department of Agriculture. Integrated Vector Management (IVM) is used to designate an approach largely building on the same principle as IPM which is also a milestone in the success story of the IPM in Sri Lanka (Administration Report, Department of Agriculture, 2002).

Pesticide malpractices and resistance

Development of pest resistance has become a serious concern so much so that in anticipation of such, led the authorities to direct that use of new generation synthetic pyrethroids in particular be restricted. After reviewing the subject of use of synthetic pyrethroids based on IRRI (1976) and Elliot et al. (1978), strict control over crop as well as usage was exercised since 1995 and the present quota for each registrant permitted is 1 600 liters per annum.

The misconception that chemical pesticides are the lasting solution in eliminating pests and vectors of diseases has led to routine and injudicious use of pesticides. With pesticides becoming less effective, users tend to increase the dose and the number of pesticide applications or by making or changing to un-recommended products. The pest problem has further aggravated by the build-up of resistant populations and the loss of natural enemies of the target pests formerly associated with agricultural cropland. A classic example is the change in status of the leaf folder of rice which was the minor pest in the past (Nugaliyadde et al. 2001) due to unscrupulous spraying of broad spectrum insecticides in rice fields.

Misuse of pesticides

Apart from residue, health and environmental effects, indiscriminate use of pesticides causes several other very serious undesirable effects such as build up of pest resistance and resurgence etc., economic losses to the farmer, effects on the yields and sustainability in agriculture. Surveys have revealed that vegetable cultivators are generally not aware of good agricultural practices and normally apply more than the recommended dose of pesticides (Jayathilake and Bandara, 1988). Excessive use of pesticides has been reported to have long term adverse effects on the immediate environment. A survey on impact of agriculture on ground water quality carried out at Kalpitiya peninsula where onion is cultivated extensively has revealed significant levels of carbofuran and very high levels of nitrate fertilizers in groundwater (BGS, 1992).

An extensive environmental study conducted at Nuwara-Eliya by the Urban Development Authority has highlighted the following areas of misuse of pesticides. Due to high cost of analysis of environment compartments for pesticides, it was conducted mainly as a survey-typed study, and the conclusion was that the environmental pollution due to pesticides should be extremely high. Accordingly, a number of measures has been recommended to reduce pesticide use, considerably. According to this study, about 80 percent of farmers use pesticides not recommended for the particular crop indicating the extent of misuse.

Current action and policies are in effect to prevent the escalation of many undesirable effects that have resulted from the dependency on pesticides. These have been primarily technical, educative, and legislative. As is mentioned elsewhere, the Department of Agriculture's policy over the last several decades has been to phase out reliance on pesticides for food production by adoption of IPM technologies such as breeding for resistance, etc.

B. Testing, quality control and effects in the field

Residues in agricultural commodities

While unacceptable levels of residue in agricultural commodities directly affect the health of the consumers, it indirectly threatens the economy of the farmer at the domestic level and the nation at international level. Studies have shown that farmers in vegetable growing areas are generally not well aware of good agricultural practices and normally apply more than the recommended dose of pesticides. Excessive use of pesticides may produce long term adverse effects on the immediate environment. In addition, precautions like pre harvest intervals are often not followed thus causing potential residue problems. Apart from vegetables, indiscriminate use of pesticides in tea can cause residue problems and the consequent repercussions in international trade. Though Sri Lanka has been acclaimed as having the cleanest and best tea in the world with respect to pesticides, there were instances where pesticide residues have been detected in the exported consignments.

In Germany, a consignment of tea from Sri Lanka has been detected with traces of PCB isomers in mid 80's. Another study conducted by M.P. de Silva and W. Thiemann in 1991 has found detectable levels of DDT, cyclodienes and lindane in tea grown in up-country, though the use of these chemicals have been banned for almost two decades. It is speculated that the residues may have been originated at the cultivation stage of tea.

In 1993, a consignment of tea was detected with a pesticide identified as ethion that has never been used in Sri Lanka in the recent past. One of the possibilities was a cross contamination during blending of teas imported from other countries by the traders.

Recently, methyl bromide traces have been detected in tea, probably by using shipping containers treated with methyl bromide before the re-entry period. Tea being the main foreign exchange earning crop of the country with around 15 percent of the total earnings, it is imperative that the highest quality is ensured of the product in order to safeguard the market and be competitive in the international trade. The Tea Research Institute, which has the mandate for research and development of tea in Sri Lanka, is extremely careful when recommending pesticides. Information based on local and international research is paid due attention to maintain the required standards up to the production level. However, possibilities of supply of sub standard pesticides to the plantation sector, sources of pesticide contamination beyond the production level needs regular monitoring by the pesticide regulatory authority, in order to decide any additional control measures should be enforced through regulatory system.

Barriers to high profit export market for vegetables

According to the data available for the early months of the year 2002, average profit margin for potato in the local market is around 100 percent, a crop considered as one of the most unprofitable due to the effluxion of potatoes to the country during past several years. In the case of rice, the profit has been ranging from 2 percent to 33 percent during different seasons. The sector would soon become economically unattractive due to rapidly changing local as well as international trade practices. A possible solution to overcome such economic drawbacks is to access the highly profitable export market.

Currently, exports of vegetables to the West and other developed countries are minimal. Pesticide residue is one of the main factors that hinder those economically sound options available for farmers. An indication of the extent of pesticide residues in agricultural commodities is the detection of significant levels in exported consignments, the only sector where any test on pesticide residues are carried-out on locally grown crops. For example, alpha and beta-endosulfan and endosulfan sulphate have been detected in chilli powder exported to Netherlands thrice in 1997 indicating the consistency of the problem (The product endosulfan is now banned in Sri Lanka). Export of gherkin was considered as a highly profitable market in the early 90's. However, only very few enterprises were able to be sustained in the business mainly due to difficulties in compliance with stringent pesticide residue requirements in the importing countries. Maintenance of high quality standards of agricultural produces conforming to the international levels is vital for such ventures. Thus, the farmers in Sri Lanka are currently deprived of their true potential. A proper management system has to be formulated based upon local pesticide residue data, with respect to actual farmer practices in the field.

High pesticide residue levels in the local diet

Public concern over pesticide residues in vegetables and fruits has been increasing during the past years. The risk of human health from pesticide residues is due to the pesticide residues in the edible part of crops and the daily consumption of crops. Although, persistent products are screened out during registration and pre-harvest intervals are given accordingly for the recommended crops in the label, the common farmer practice of applying pesticides close to harvest and sometimes even after harvesting for protection during transport and marketing do raise concerns of high levels of residues in foods.

There are no comprehensive studies done in the recent past to assess the residue levels in vegetables and fruits. Although, organochlorine insecticides such as aldrin, DDT, dieldrin, endrin, HCH, heptachlor, and lindane have been phased-out from use in Sri Lanka, at least since two decades ago, their residues may still remain in the environment. A survey of organochlorine insecticide residues conducted in 1979 has revealed traces of residues in vegetables as well as in soil and water. As some of those chemicals are potential carcinogens, presence of traces in the environment poses serious threat to human health. However, a limited study conducted by the Office of the Registrar of Pesticides in 2000 for few vegetable and fruit samples collected from the market (imported fruits such as grapes and pear samples with known origin obtained at the entry of point were also included) confirmed that the residues in tested samples contained within the acceptable levels for pesticides which included organophosphates, carbamates, organochlorines and carcinogens.

Unfortunately, there is no program currently in place in the country to conduct continuous monitoring of residues, due to lack of required laboratory facilities. Regulatory authorities have the necessary mandates for establishment of Maximum Residue Limits (MRL) for crops with respect to pesticides registered in the country. It enables to determine the Pre-Harvest Intervals (PHI) for pesticides given in the label for the farmers to follow, thus maintaining residue in acceptable levels. These vital parameters have to be developed under local conditions as the behavior of pesticides in the environment is greatly dependent on local environmental conditions and human intake of such residues further depended upon the cooking and eating habits of the society.

Toxic by-products and impurities

Apart from the inherent toxicity of pesticidal substances, the hazard of the final marketed product is greatly dependent upon the impurities as well as nature and quality of the other ingredients incorporated in the preparation. In spite of assurance of quality through registration procedure, which mainly focuses on the literature of the product, there were number of occasions where inferior quality has been reported in products offered to the farmer. It is believed that a large number of such incidents are not reported due to lack of proper investigation and recording system in every related discipline. Ethylene thiourea (ETU), an impurity in one of the most extensively used class of fungicides, is a potential carcinogen. Under careful controlled manufacturing procedures, the level of this very dangerous substance can be maintained below the harmful level. Since this class of fungicides has become a commodity in the international market, there are number of manufacturers and some may not be capable of always confirming to the required standards. There are several similar situations exist in this field. Thus, it is vital that routing testing of quality standards is carried out by the regulatory authorities for such products to ensure the safety.

Another field survey conducted by the Office of the Registrar of Pesticides in collaboration with the University of Professional Education, Netherlands reports that a large extent of land has been abandoned at Matale as vegetables are not grown any longer due to extensive use of pesticides and fertilizer in the past. The real environmental impact has yet to be properly studied. A survey on impact of agriculture on ground water quality carried out at Kalpitiya peninsula, where onion is cultivated extensively has revealed significant levels of carbofuran and very high levels of nitrate fertilizer in ground water.

These studies clearly indicate the extent of the problem with respect to pesticides in Sri Lanka. However, an exact account of the extent of environmental pollution due to pesticides is far from the reality due to severe shortage of field data. Thus, it is essential that a comprehensive program should be drawn-up to address the issues individually and effectively and implemented immediately to safeguard the people and the environment.

C. Health and environmental information

Pesticides are known to have the potential to cause irreversible and debilitating damage on the ecosystem and species populations, including humans. There are serious concerns among the international scientific community on adverse human health and wildlife effects due to specific group of chemicals known as "Endocrine Disruptors" (Colborn, et al., 1996; EDSTAC, 1998). Among the suspected EDs, there are number of compounds classified under the Stockholm Convention which have been used widely in the past in Sri Lanka and some are non-persistent pesticides are still widely used in the country (i.e. mancozeb, malathion, carbaryl, chlorpyrifos, dimethoate) (Sumith, 2001). The indirect toxic effects of these pesticides on wildlife and birds have been studied in detail through field studies in other countries.

Although some data are available concerning the concentration of limited number of pesticides in surface waters, river waters, etc. in Sri Lanka (BGS, 1992; Silva, et al., 1991) little or no information is available concerning the biological significance. Isolated incidences of pesticide related deaths of fish populations, snakes, etc. have been reported in surface waters following heavy application of mostly organophosphate and carbamate type of pesticides in agricultural fields without possible long-term environmental damages. Also, scattered incidences are reported to the Office of the Registrar of Pesticides on deaths of peacocks and other birds due to the consumption of rice grains treated with insecticides.

Accidents and occupational exposure

The acute pesticide poisoning effects often resulted in mortality are easily noticeable from sub-lethal effects which require exposure to pesticides for a longer period of time. Though it is likely to be prevalent, long-term effects are either not diagnosed properly in some cases or difficult to establish the actual causative agent under the conditions prevailing in Sri Lanka. Since all persistent pesticides are banned for more than a decade, any observable effects due to persistent pesticides should have been associated with long-term sub lethal exposure from contaminated environmental compartments and food chains. Such effects are most often not studied to identify or associate with the cause though it is widely believed that cases of chronic health problems such as carcinogenicity and reproductive effects are rapidly increasing. Thus the real effects of persistent pesticides are often underestimated.

Easy accessibility and irresponsible handling of pesticides have contributed to a greater extent aggravating to this situation. But, on the other hand, the accidents and occupational exposure are far less reported than anticipated when compared to the suicide statistics, mainly because of the differential administrative approaches in case of poisoning and comparatively low mortality rate in accidents. Senanayake et al. conducted research on the neurotoxic effect of organophosphorus insecticides, and observed secondary effects, which have not been recorded earlier. Women and children are often the victims of pesticide related accidents, especially in the farming communities. Effective awareness campaigns, focused at different target groups through proper modes of communications, are essential to protect those vulnerable sections of the society. Scarcity of such reports greatly handicapped making necessary policy and regulatory measures to ensure human safety.

Poisonings in occupationally exposed persons are usually associated with contract spray operator groups or farmers carrying out prolonged spray operations under hot humid conditions, without adequate personal protection. Recent poisoning data revealed >80 percent of poisonings caused by pesticides to be due to willful ingestion of pesticides for self-harm (Ref. Police Data on Suicides, 1998; Annual Poisoning Reports 1990-1996, National Poison Information Center). In 1979, out of all pesticide poisonings recorded, 73 percent were suicidal attempts with unintentional poisonings accounted for occupational exposure and accidental exposure incidences reported to be 16 percent and 7 percent, respectively (Jeyaratnam, et al., 1982). Though the use of highly hazardous pesticide formulations (WHO hazard class Ib), such as monocrotophos 60 percent SL, methamidophos 60 percent SL, endosulfan 35 percent EC, carbosulfan 20 percent EC, etc., have been restricted or banned, poisoning was considered severe based on percentage of persons affected and recurrent of episodes.

Many examples worldwide have shown that restricting the availability of toxic pesticides can reduce death rates from self-harm. WHO has suggested that death rates could be reduced by restricting the availability of poisons commonly used for self-harm (WHO, 2001). For example, a national ban on the organophosphate parathion reduced the total number of deaths reported to a poison center in Rosario, Argentina during the 1990s. (Piola et al., 2001) As shown in the Table 3, it is possible to speculate that while the total deaths due to pesticides from 1983 through 1990 remains more or less stable, the death caused by organochlorines became gradually decreased, basically due to the restrictions and banning of some of the organochlorine candidates during that specified period.

A case study conducted at the Anuradhapura hospital showed that due to recent ban of endosulfan products (35 percent EC formulations of WHO hazard class Ib) in Sri Lanka (the last member of organochlorine pesticide) in 1998, the number of deaths of endosulfan poisoning fell quickly from 50 in 1998 to 3 in 2001 along with a fall in the total number of pesticide deaths (Roberts et al., 2003). The overall reduction on total death rates amidst the rising incidence of self-poisoning due to pesticides from 1998 through 2001 (Table 4) would have been due to displacement of a poisoning candidate (viz. endosulfan) which has a higher Case Fatality Rate (CFR) (42 percent) than that of common organophosphates (29 percent) concluded the beneficial impacts of pesticide regulation on deaths from poisoning in Sri Lanka (Roberts et al., 2003).

Table 3. Total pesticide poisoning episodes during 1983-1990

Source: Ministry of Health Statistics Division Personal Communication, Prof. Ravindra Fernando, University of Colombo, Department of Forensic Medicine, Colombo.

Table 4. Total pesticide poisoning episodes during 1996-2002

Source: Annual Poisoning Data, National Poison Information Center, Colombo.

Field studies revealed that 805 farmers suffered from symptoms of acute poisoning following spray sessions. However, only 20 percent underwent hospital admissions on occupational exposure (Environment Action Plan Report, 2002). Concerns of chronic health effects associated with pesticide residues in food and water sources are becoming more and more intensified with frequent reports of life threatening cases such as Chronic Renal Failure in Padaviya and Madawachchiya (Palitha Bandara, personal communication) and ever increasing numbers of cancer patients. The farming communities whose rely on agro-wells in intensively cultivated areas for their basic needs such as for drinking and washing purposes are at particular risk of pesticide residues.

Deficiencies in health related information collection and recording, prevalent in the system, has very seriously effected the formulation of effective control strategies for proper management of pesticides in the field.

Contaminated sites and environmental effects

Contaminated sites are identified as having a history of heavy previous use or locations where pesticides are transported into and deposited on those sites. Though a somewhat complete picture on available stockpiles can be drawn, which is estimated to be 166 metric tons, the situation on contaminated sites with regard to POP pesticides is obscure. DDT and subsequently BHC had been used for malaria vector control programs as a household residual insecticide; door-to-door application in malaria-infested areas in the Dry Zone (Herath, 1984) and in the Wet Zone including some areas of the Colombo district (Dr. R.R.M.L.R. Siyambalagoda, Director, Anti Malaria Campaign-personal communication). Agricultural uses were basically on coconut plantations, tea plantations, horticultural projects and tobacco nurseries. However, area specific potential contamination (non-point pollution sources) could be predicted for aldrin, chlordane, DDT, dieldrin and heptachlor for which there were specific agricultural uses in plantations, horticultural nurseries, non-food crops (e.g. tobacco) and in non-agricultural termite control uses.

Although DDT was totally banned as early as 1976, its precursors and derivatives could be present in the environment for a long period of time and thus could contaminate agricultural produces. In tea, DDT isomers could have been originated from heavy use of dicofol in the past which could be contaminated with DDT isomers depending on the production process adopted in manufacturing dicofol. Due to this reason, the use of dicofol in tea commenced in 1965 was prohibited in 1994. The total consumption of 42 percent dicofol (Kelthane) emulsifiable concentrate formulation was 2 084 liters from 1988-1992. A large number of estates in Uva, upcountry and mid country experienced heavy mite infestations during dry weather periods necessitating repeated use of miticides (Vitharana, 2003). Therefore, the detection of these pesticides in the environment may be due to agricultural run-off and excessive use or misuse in the past.

There is no planned monitoring system or infrastructure facility available with the pesticide registration authority to trigger remedial actions to mitigate the problems. So far no proper monitoring studies have been carried out on pesticides. Further, there is no surveillance system in place in the health sector to monitor the trends of health effects with respect to exposure to pesticides from environmental contamination. The data available in environmental concentrations are primarily produced for academic interests or data generated for export of agricultural commodities as a requirement from importing countries (residue levels) rather than for environmental or long-term monitoring purposes. This leads to rather discrete data coverage (spatial and temporal) which makes it difficult to evaluate significant trends of contamination by persistent pesticides in the country.

Limited data available from a study conducted in 1999-2000 (Industrial Technology Institute) revealed the presence of some DDT residues in the form of p,p'-DDE at 2-5 µg/kg in bottom sediments in Hambantota coastal zone and up to 9.6 µg/kg of DDTs in sediments of Colombo port, though DDT was not in use in Sri Lanka for more than 30 years. The presence of DDT in the form of p,p'-DDE in almost all samples (6) in Hambantota coastal zone and though it is as high as 40-100 µg/kg in Beira Lake in Colombo (ITI, 2004), suggests the general absence of recent DDT sources in those areas. A similar trend have been observed by Guruge and Tanabe (2001) that >70 percent of total DDTs in sediments sampled from Negombo Lagoon, Chilaw Lagoon, Udappuwa and Mundal Lake were in the form of p,p'-DDE where they have concluded as insignificant local usage in recent times. However, the question on recent DDT sources remains active by the detection of DDT in the Colombo Port as reported elsewhere (ITI, 2000) in the form of p,p'-DDT and DDD in one out of 18 samples. More strikingly, the reason for the high p,p'-DDT concentration in Rabbit Fish (p,p'-DDT:DDT was 74:120) from the Colombo Dockyard was also unknown (Guruge and Tanabe, 2001). More data is needed to make a reasonable scientific judgment whether it was due to inland sources or due to other transport mechanism of persistent substances.

Very little information is available on the concentration of chlordane in the environmental compartments despite the fact that chlordane has been used in Sri Lanka until recently compared to other persistent pesticides which have been banned long ago. Studies conducted by Guruge and Tanabe (2001) confirmed possible recent usage of chlordane in Sri Lanka by observing similar trend in ratio of trans-chlordane in biological samples and sediments to that of technical chlordane. Also, the total chlordane concentration in the Kelani River was found to be higher than those concentrations reported from most developing Asian countries, reasoning for possible recent usage of chlordane in the up-stream areas of Kelani River (Guruge and Tanabe, 2001). There are few citations on the presence of several persistent pesticides in vegetables, processed products and export products, particularly DDT, dieldrin and heptachlor. Available recent data is so limited about their environmental concentrations. The probable reason may be that most of these pesticides are either not formulated or not used in Sri Lanka and even it used not in large quantities or banned long time ago thereby diluting their levels in the environment quite considerably with time.

As discussed above, some of the organochlorine concentrations are still found in some environmental compartments, coupled with the lack of knowledge on the true picture of toxicological impact of persistent pesticides in the environment and human health point of view, the situation would have to be seriously dealt with to achieve environment and human health protection goals. In this context, further research, monitoring and environment protection procedures are critically needed in Sri Lanka.

Conclusion

Recurring problems encountered by the Office of the Registrar of Pesticides are often related to (a) the reliability of data submitted for registration; (b) the reliability of quality certificates for commodity products; (c) adulteration at field level; and (d) re-labeling of outdated pesticides. In-house product quality testing programs are not in place due to manpower development in the field of pesticide quality and residue analysis. The registration authority is therefore unable to check imported consignments with sufficient coverage and has to depend on Quality Certificates submitted by the basic manufacturer or formulator of the exported commodity products. In spite of assurance of quality through registration procedure, which mainly focuses on the literature of the product, there were number of occasions where inferior quality has been reported in products offered to the farmer. It is believed that a large number of such incidences are not reported due to lack of proper investigations and recording systems in every related discipline. In the case of commodity products from doubtful sources, as a means of cross checking their Quality Certificates, the services of independent testing laboratories have been employed. Irrespective of the presence or not of regulatory systems in individual countries, it appeared that the maintenance of quality of pesticide products is becoming a challenge. Thus, it is vital to strengthen the analytical capabilities at the regulatory authorities so that routine testing of quality standards are carried out for commodity products to ensure the safety.

While the services of independent laboratories can be utilized for basic product related data generation and for other specific testing programs with respect to pesticide registration compliance, surveillance on enforcement activities and internal verifications in pesticide management activities are essential and is a necessary mandate of the regulatory authority. Therefore, it should be considered as an urgent need to strengthen relevant capacities at the Office of the Registrar of Pesticides, for this purpose.

As a social and environmental security measure, regardless of whether and how pesticides affects human and wildlife (where a highly organized scientific investigation is required for assessing the risks of pesticides in the areas of human health and environmental effects), it is an important aspect to assess human health and the environment against anticipated toxic effects highlighted through various epidemiological and other studies. Therefore, monitoring and surveillance of pesticides in environmental compartments are a necessary for the protection of health of human beings, wildlife and the environment.

Some of the priority areas identified for effective and efficient management of pesticides in the country are as follows.

1. Disposal of existing stocks of outdated pesticides.

2. Development of infrastructure at Office of the Registrar of Pesticides and Customs for compliance monitoring programs with respect to contamination/adulteration of pesticides.

3. Surveillance on environment compartments (air, sediments, water, soil, biological) and food products for presence of pesticides, including:

• Assessment of pesticides residues for ground and surface water bodies.

• Further investigation on the presence of persistent pesticide residues in coastal seabed.

• Study of all pesticides recommended for agriculture on the fate and effects in the environment under the local conditions to ascertain any relevance to persistent qualities.

• Establishment of MRLs for Sri Lanka and devising methods to minimize the residue levels in agricultural commodities.

• Establish regular pesticide residue monitoring programs on food (local and imported) by strengthening the relevant aspects under the Law.

4. Surveillance on adverse effects of pesticides on the environment and human health under the local conditions by:

• Establishment of a proper surveillance and reporting system (social and scientific) within the health sector on chronic health effects from exposure to pesticides.

• Establishment of complimentary analytical programs to study the fate of such pesticides in the environmental compartments for the establishment of correlations between presence and their health effects.

5. Development of a coordinating system by establishing a network among the health, agriculture, industry and environmental sector research groups through the Office of the Registrar of Pesticides as the focal point for coordination, information collection and sharing and policy decisions for prevention of pesticide related adverse effects.

6. Awareness on relevant responsibilities and issues for all stakeholders in pesticide management.

7. Public awareness campaigns and programs through printed and electronic media in order to achieve the necessary levels of awareness on pesticides.

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QUESTIONNAIRE SUMMARY

Sri Lanka

Selected Country Statistics:

GDP = Gross Domestic Product; GNI = Gross National Income; Hunger = Population below minimum energy requirement; FAOSTAT = latest data entry between 1998 and 2002

Institutional Profile

Industry Associations: CropLife Sri Lanka

Non-Governmental Associations: VIKALPANI Fed., Center for Environmental Justice

Questionnaire responses: Yes = Yes; - = No; ? = don't know; (blank) = no answer