338 Elba M. de la Cruz and Luisa E. CastilloChapter 12 The use of pesticides in Costa Rica and their impact on coastal ecosystems Elba M. de la Cruz and Luisa E. Castillo INTRODUCTION Costa Rica is the second smallest country in Central America, with an area of 51,100 km 2 , and extends from approximately Lat. 8 ° to 11 ° N and between Long. 83 ° and 86 ° W. Costa Rica is bordered by Nicaragua on the north, Panama on the south, the Caribbean Sea on the east, and the Pacific Ocean on the west. It has an elongated form that stretches from northeast to southeast with a greatest length of 480 km on the northwest–southeast axis and a narrowest width between the Caribbean and the Pacific of only 118 km (Figure 12.1). The highest regions of Costa Rica are in the center of the country; its lowlands are more extensive and flat on the Caribbean side and to the north than on the Pacific side. Costa Rican geology dates from 150 M years ago; the consolidation of its mountainous backbone was associated with a long history of volcanic activity. Sixty-eight volcanoes have been identified of which nine are considered to be active. Its mountainous backbone can be divided into two units, separated in the middle of the country by two valleys, those of the Rio Grande de Tárcoles and the Reventazón (Castillo-Muños, 1983; Trejos, 1991). Costa Rica has a patrimonial sea area of 520,000 km 2 , about 10 times its national territory, although the characteristics of the Pacific and the Caribbean coastal regions are quite different. The Caribbean Coast is straight and short, 212 km, while the Pacific Coast is very irregular with many peninsulas, capes, points, islands, and gulfs over a length of 1,328 km (Quesada, 1990). Costa Rica’s tropical location between two oceans with its complex mountain systems causes a great variety of climatic conditions. There are two defined rainfall regimes: one for the Caribbean side and another for the Pacific side. On the Caribbean side, including both the northern lowlands and the Caribbean coastal regions, there is not a defined dry season. In the coastal zone, there are relatively dry periods, one in March and April and another in September and October. On the Pacific side there are two distinct seasons: one rainy and one dry. The rainy season extends from May to the middle of December and the dry season runs from January to April. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts The use of pesticides in Costa Rica 339 A mountainous backbone, coupled with abundant rainfall, results in Costa Rica having an extensive hydrographic system. The Costa Rican Electricity Institute has divided this hydrographic system into 34 watersheds. The system comprises two versants, one toward the Pacific side and another toward the Caribbean side (Trejos, 1991). The later is usually subdivided into two parts. A northern sub- versant carries water toward Lake Nicaragua and the San Juan River and through it to the Caribbean. The Caribbean or Atlantic sub-versant, carries water directly to the Caribbean. Due to the narrowness of its territory, Costa Rica has relatively small watersheds (Trejos, 1991). The largest watersheds – those more than 2,000 km 2 – include Grande de Térraba (5,000 km 2 ); Tempisque (3,400 km 2 ); Reventazón- Parismina (3,000 km 2 ); Sixaola (2,700 km 2 ); San Carlos (2,650 km 2 ); Grande de Tárcoles (2,150 km 2 ); and the Sarapiquí (2,150 km 2 ). Costa Rica is a democratic republic; its Constitution established that the govern- ment of the republic is to be exercised through three distinct and independent powers: the Legislative, Executive, and Judicial powers. Costa Rica’s territory is divided into seven provinces including San José (the capital), Alajuela, Cartago, Heredia, Guanacaste, Puntarenas, and Limón. These provinces are subdivided into cantons and in each canton there is a municipality whose leaders are elected by the people to administer the community’s interests (Trejos, 1991). Figure 12.1 Costa Rica’s location and primary river systems © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 340 Elba M. de la Cruz and Luisa E. Castillo PESTICIDE REGULATIONS Control of pesticide labeling and handling in Costa Rica is primarily the respon- sibility of the Ministries of Agriculture and Health. Pesticide use was first regulated by a 1954 law requiring information on the physical properties, recommended uses, and health risks of all locally produced and imported pesticides. Then in 1976, the Regulation on Pesticide Control was passed to implement procedures for the registration and control of all pesticides with both agricultural and domestic uses entering the country. Evaluation of a pesticide’s toxicity is the duty of the Ministry of Health. This ministry had, and still has, the authority to ban or restrict registered uses of a compound if they consider it dangerous to human or animal health (Castro, 1998). There are two primary laws and many related laws and regulations controlling the major aspects of pesticide use in Costa Rica. The Phytosanitation Protection Law of 1968 (revised in 1978 and 1997) is administered by the Ministry of Agriculture and the General Law of Health 1973 (revised in 1975, 1980, 1982, and 1988) is administered by the Ministry of Health. The Ministry of Agriculture has complete authority to regulate the use of all agricultural crop protection chemicals including their environmental, wildlife, and human health effects. They also have the right to determine when chemical control must be replaced by biological control to reduce environmental pollution. Under the authority of the General Law of Health, the Ministry of Health promulgates rules for importing, handling, storing, transporting, marketing, distributing, and applying pesticides. All pest control products not under the Phytosanitation Law and capable of poisoning or causing serious damage to the health of humans or non-target organisms must be registered and receive a permit from the Ministry of Health before being used. This law allows health authorities to institute certain preventive measures, e.g. to retain or remove products from the market, to destroy or neutralize contaminated materials, and to confiscate damaged or suspicious products. They also have the authority to close pesticide storehouses, formulating plants and retail shops, and cancel pesticide permits or registrations (Castro, 1998). In 1989, the National Pesticide Use Advisory Commission was reorganized – the previous commission was created in 1972 – and tasked to evaluate the toxicology of pesticides, to recommend banning dangerous substances, to re-examine approved pesticide registrations, and to make suggestions or observations to the Ministries of Agriculture and Health (Hilje et al., 1992; Castro, 1998). It may re-evaluate a registration acting upon a request from one of the Ministries (Castro, 1998). The 1989 Commission is composed of nine members with two representatives from the agrochemical industry, two from the Ministry of Agriculture, and one each from the Ministry of Health, the National Agronomist Association, the Ministry of Work and Social Security, the Ministry of Environment and Energy, and the National Center for Poison Control (Castro, 1998). The Commission is responsible for coordinating its activities and developing consensus recommendations from stakeholders among different pesticide-related interest groups. The law ‘Regis- tration, Use and Control of Agriculturally Used Pesticides and Related Products © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts The use of pesticides in Costa Rica 341 (1995)’ regulates a pesticide’s commercial life including registration, labeling, unloading, manufacturing, formulation, packaging, commerce, storage, transport, use and management, destruction of empty pesticide packages, pesticide residues, unused pesticides, and spill cleanup. In principle, all occurrences of acute, subacute, and chronic effects from either a voluntary or accidental pesticide poisoning must be reported to the Ministry of Health – charged with keeping a registry of these cases. Every person who handles or applies pesticides on a regular basis must have a pre-exposure medical checkup followed by an annual medical checkup. In special cases, medical checkups may be more frequent. The law does not allow persons less than 18 years old to work with or apply pesticides. Persons applying pesticides by aerial or ground application methods must inform the Ministry of Agriculture of the date, time, location, pesticide, and method of application at least 72 h in advance. The local Ministry official then notifies apiculturists 48 h in advance to protect their bees and beehives. Signs must be posted to warn people to keep themselves and their animals out of the application area. Controls and procedures following accidents are not well established in the law. Responsibility can rest with the landowner (for failure to inform the Ministry of Agriculture), the owner of the aerial (crop dusting) application company (for a malfunctioning airplane), the pilot (for spraying the wrong field), the professional agriculturist (for recommending the wrong products or application rates), or even the injured party (for failure to protect himself or his animals). Water resources are protected under two laws, one promulgated in 1989 to protect important aquifers and the other in 1997 to regulate industrial wastewater and effluents. The initial use of water quality criteria in Costa Rica was to legislate pesticide residue concentrations in water bodies. The maximum allowable pesticide concentrations in waste or natural waters are 0.05 mg L –1 for ∑-OC pesticides and 0.1 mg L –1 for both ∑-OP and ∑-carbamate pesticides (Castro, 1998). Agricultural and other pest control practices in Costa Rica are highly dependent on synthetic pesticide use. However, no official policy exists to reduce the quantity of pesticides used or to change from the more toxic and dangerous products to less toxic ones. A list of the a.i.(s) regulated or prohibited in Costa Rica is presented in Table 12.1. Pesticides classified as highly toxic are restricted for use and can only be sold with a professional prescription. Even though there are laws and regulations governing pesticide use in Costa Rica, these are often transgressed, causing health and environmental problems. These problems include exposure and poisoning of workers and the general popula- tion (with some individuals being less than 18 years old) and exposure of aquatic organisms, domestic animals, and wildlife with fatal consequences occasionally resulting from the exposures. Improved laws, especially in environmental quality criteria, and improved implementation and enforcement is a must. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 342 Elba M. de la Cruz and Luisa E. Castillo PAST AND PRESENT PESTICIDE USE IN COSTA RICA Pesticide imports Environmental problems created by the misuse of pesticides in developing countries are extensive. Costa Rica, having an agriculture-based economy, has also been influenced by the production of these chemicals. Information regarding methods of pest control during pre colonial, colonial, and republican times is almost non- existent (Hilje et al., 1989). The first chemical used to control pests in Costa Rica was called ‘Tree Tanglefoot’ – a product made from natural tree resins which have been polymerized with castor oil and further waterproofed with vegetable waxes; its mode of action is mechanical – and was introduced by 1916. In 1926, copper Table 12.1 Pesticides with prohibited or restricted use in Costa Rica a Year a.i.(s) Legal status 1960 cianogas prohibited 1960 mercurial prohibited 1982 arsenic compounds b prohibited except they could still be used to combat fungal diseases in coffee 1987 carbofuran, ethyl parathion, methyl restricted use; sold only with parathion, phosphine, phorate, authorization and red strip label monocrotophos 1987 2,4,5-T prohibited 1988 aldrin, DDT c , dieldrin, toxaphene, prohibited chlordecone, chlordimeform, dibromochloropropane, ethylene dibromide, dinoseb, nitrofen 1989 captafol prohibited 1990 lead arsena(i)te b , endrin, penta- prohibited chlorophenol, cihexatin 1991 chlordane, heptachlor all uses prohibited in 1998 1992 daminozide restricted use; only for ornamental plants 1995 methyl bromide restricted use 1996 captan restricted use 1996 lindane and its isomers, ethephon d prohibited 1998 declorane (mirex) and arsenic prohibited compounds b Notes: a Source: adapted from Castro, 1998; UNA/IRET, 1999; Phytosanitary Department of the Ministry of Agriculture, Costa Rica. b Lead arsen(i)ate was prohibited in 1990. However, in 1991, its use was again permitted. It was in 1998 that importation and use of all arsenic compounds was prohibited in Costa Rica. c Law still allows the Ministry of Health to use DDT in exceptional situations for combating malaria-carrying mosquitoes when there is no alternative. d Ethephon is banned only for coffee bean ripening. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts The use of pesticides in Costa Rica 343 sulfate was used extensively to combat diseases in crops. During this time the convenience of using chemical substances to control any pest damaging a crop was already a common thought among farmers (Hilje et al., 1989). Since then, pesticide importation and use in Costa Rica has slowly increased, reaching its highest quantities after 1992. Figure 12.2 shows the quantity of formulated pesticides imported from 1970 to 1996. Even though the available pesticide import data has always been deficient, in the 1980s and 1990s the nature of the data permitted separation of disinfectants, organic solvents, and other similar products and the calculation of kg of a.i. being imported. The quantity of formulated pesticides imported during 1970 amounted to 5.6 M kg and in 1996 surpassed 14 M kg (Figure 12.2). The imported quantity of pesticides had risen to 18 M kg in 1997 (de la Cruz et al., 1998). There was a modest reduction in the quantity of pesticides imported during the late 1980s. The reasons for this may be attributed to improvements in the data registers, which permitted better separation of other products from pesticides, and decreases in the prices of Costa Rican export cash crops. The increase in the quantity of pesticides imported during the 1990s must be attributed to the expansion of cultivated area for highly pesticide dependent crops, e.g. banana, rice, melon, watermelon, pineapple, and ornamental plants, during the same period. In Costa Rica, the most important pest control method for insects, other invertebrates, vertebrates, weeds, and diseases is pesticides (Hilje et al., 1992). Hilje (1984) has calculated that in 95 percent of the cases where an insect was the organism causing damage on a plantation, it was controlled with pesticides. 0 4,000 8,000 12,000 16,000 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 Year Tonnes importedD Figure 12.2 Tonnes of formulated pesticides imported by Costa Rica from 1970–96 (adapted from Castillo et al., 1989; Hilje et al., 1992; IRET database) © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 344 Elba M. de la Cruz and Luisa E. Castillo The type of pesticides used in Costa Rica has also changed with time. Neverthe- less, about 13 products have dominated the import list for the last 12 years (1985 to 1997), among them mancozeb, 2,4-D, glyphosate, chlorothalonil, ethoprophos, paraquat, terbufos, cadusafos, methyl bromide, carbofuran, propanil, tridemorph, and fenamiphos (Table 12.2). During the 1990s, the nematicide cadusafos became a dominant imported pesticide. It is primarily used on banana plantations and was heavily imported at the beginning of the 1990s, but by 1995 the quantity of imports was reduced due to its high price. Then, traditional products such as terbufos, carbofuran, and ethoprophos again increased (Chaverri and Blanco 1995; IRET database). Inorganic pesticides, e.g. copper and sulfur related compounds, constituted the bulk of pesticides used before the 1950s. OC insecticides predominated during the 1960s and 1970s. From 1977 to 1979, about 815 T of OCs including DDT, dieldrin, heptachlor, chlordane, aldrin, endrin, toxaphene, endosulfan, and lindane were imported. By the 1987 to 1989 period, the quantity of OCs had declined to 242 T and included declorane (mirex), lindane, chlordane, heptachlor, penta- chlorophenol, and endosulfan. From 1995 to 1997, only about 183 T of the OCs endosulfan and chloroneb were imported (Vega et al., 1983; Hidalgo, 1986; Castillo, et al., 1989; Hilje et al., 1989; Hilje et al., 1992; Instituto Regional de Estudios en Sustancias Tóxicas (IRET) database). The dramatic reduction in the importation of OC pesticides can be attributed to prohibition and other restrictive regulations imposed on their use by Costa Rica. Other organic pesticides, e.g. dithiocarbamates, carbamates, phenoxyacetic acid, OPs, benzonitriles, morpholines, bipyridils, anilides, triazines, and pyrethroids, replaced the OCs during the 1970s to the 1990s. From 1970 to 1979, no detailed import records of a.i.(s) and quantities exist, but products including mancozeb, methyl bromide, aldicarb, 2,4-D, glyphosate, chloro- thalonil, tridemorph, terbufos, paraquat, propanil, ethoprophos, cupric compounds, diuron, methamidophos, carbofuran, carbendazim, thiabendazole, and terbuthyl- azine were being imported (Vega et al., 1983). DBCP, a well-known nematicide with negative effects on male reproduction, was also imported during this time. Currently Costa Rica imports approximately 280 pesticides that are sold under more than 2,000 different brand names (IRET database). From 1992 to 1997, Costa Rica imported about 40.1 M kg of pesticide a.i.(s) (Figure 12.3 A) for approximately US$530 M (Figure 12.3 B) and the yearly quantity of pesticides imported continued to increase during the period. Total pesticide a.i. imports in 1997 (8,972 T) were 59 percent higher than in 1992 (5,656 T) (Figure 12.3 A) and an increase of 39 percent for formulated products occurred over the same period. The cost of these pesticides escalated from US$74.6 M to US$117 M for the same period (Figure 12.3 B). Of the a.i.(s) imported by Costa Rica between 1995 and 1997, 17 constituted 80 percent of the total quantity of pesticides imported (Table 12.3). A comparison of the biocide groups imported during the periods 1977 to 1979, 1985 to 1987, and 1995 to 1997 is shown in Figure 12.4. During the 1970s, © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts The use of pesticides in Costa Rica 345 Table 12.2 The 25 most imported pesticides in Costa from 1985–97 a Pesticide Tons b % of total ∑ % Pesticide Tons b % of total ∑ % mancozeb 27,265.8 20.3 20.3 Aldicarb 2,767.6 2.1 68.5 2,4-D 8,509.9 6.3 26.6 Carbaryl 2,562.3 1.9 70.4 Glyphosate 6,472.3 4.8 31.4 Foxim (phoxim) 2,456.7 1.8 72.2 Chlorothalonil 5,925.5 4.4 35.8 Diuron 1,710.0 1.2 73.5 Ethoprophos 5,847.2 4.3 40.2 2,4-D + Picloram 1,355.7 1.0 74.5 Paraquat 5,530.0 4.1 44.3 Maneb 1,310.8 1.0 75.5 Terbufos 5,136.7 3.8 48.1 Oxamyl 1,205.8 0.9 76.4 Cadusafos 4,736.7 3.5 51.6 Terbutryn 1,168.5 0.9 77.2 Methyl bromide 4,698.1 3.5 55.1 Methamidophos 1,149.4 0.8 78.1 Carbofuran 4,515.7 3.4 58.4 Pendimethalin 1,142.0 0.8 78.9 Propanil 4,319.6 3.2 61.7 Terbuthylazine 1,136.2 0.8 79.8 Tridemorph 3,380.3 2.5 64.2 Propiconazole 1,091.5 0.8 80.6 Fenamiphos 3,040.6 2.3 66.4 Total imports 134,545.2 100.0 Notes: a Source: adapted from IRET database. b Includes only formulated products; except for 2,4-D + picloram, the a.i.(s) in mixtures are not included. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts 346 Elba M. de la Cruz and Luisa E. Castillo herbicides (35.3 percent), insecticides plus nematicides (30.1 percent), and fungicides (22.8 percent) were the most imported biocide groups. The later two periods differ from the 1977 to 1979 period, but were similar to each other. In them, the most imported biocide groups were the fungicides (45.9 percent and 47.1 percent, respectively), followed by the herbicides (28.0 percent and 26.5 percent, respectively), and the insecticides plus nematicides (23.1 percent and 16.3 percent, respectively). In the 1995 to 1997 period, fumigants, e.g. methyl bromide, constituted 10 percent of total pesticide imports. Generally, fungicides, herbicides, and Figure 12.3 Tonnes of pesticide a.i.(s) imported by Costa Rica from 1992–97 and the cost of pesticide a.i.(s) imported from 1992–97 (adapted from Castillo, 1997; de la Cruz et al., 1998; IRET, database) B. Cost of pesticides 0 20 40 60 80 100 120 140 1992 1993 1994 1995 1996 1997 Cost of pesticides (US$M) A. Quantity of pesticides imported 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 1992 1993 1994 1995 1996 1997 Tonnes a.i. imported © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts The use of pesticides in Costa Rica 347 Table 12.3 Major pesticide a.i. imported from 1995–97 in Costa Rica a a.i. Chemical family Biocide action b Imported (T) Cumulative (T) Cumulative % Mancozeb dithiocarbamate fungicide 5,702.9 5,702.9 25.8 Methyl bromide halogenated aliphatic fumigant 2,168.3 7,871.2 35.6 2,4-D phenoxyacetic acid herbicide 1,973.4 9,844.6 44.5 Glyphosate organophosphorus herbicide 1,414.7 11,259.3 50.9 Chlorothalonil chlorobenzonitrile fungicide 1,223.2 12,482.5 56.4 Tridemorph morfoline fungicide 1,082.1 13,564.5 61.3 Terbufos organothiophosphate ins/nem 965.0 14,529.6 65.6 Paraquat quaternary ammonium herbicide 483.5 15,013.1 67.8 Propanil anilide herbicide 473.9 15,487.0 70.0 Ethoprophos organothiophosphate ins/nem 339.7 15,826.7 71.5 Cupric inorganic ins/acar 333.5 16,160.2 73.0 Methamidophos phosphoramidothioate ins/nem 315.1 16,475.3 74.4 Cadusafos organothiophosphate ins/nem 271.2 16,746.5 75.6 Diuron phenylurea herbicide 262.0 17,008.5 76.8 Propineb dithiocarbamate fungicide 261.1 17,269.6 78.0 Carbofuran benzofuranyl methylcarbamate ins/nem/acar 249.0 17,518.6 79.1 Terbuthylazine chlorotriazine herbicide 204.4 17,723.0 80.0 Total 90% a.i. 19,991.8 Total 100% a.i. 22,134.9 Notes: a Source: adapted from IRET database and de la Cruz et al. , 1998. b Biocide abbreviations indicate: ins. for insecticides; acar. for acaricides; and nem. for nematicides. © 2003 Milton D. Taylor, Stephen J. Klaine, Fernando P. Carvalho, Damia Barcelo and Jan Everaarts [...]... point Pre-planting weed control: herbicides soil insects: insecticides Post-planting soil and stem insects: insecticides Pre-emergence and Post-emergence herbicides soil and foliar insets: insecticides Blooming foliar and spike insects: insecticides diseases: fungicides Pesticide storage facilities cellar, mixture preparations runoff, erosion non-point aerial drift runoff, erosion non-point aerial drift... of the pesticides, loss mechanisms including microbial degradation and volatilization, and processing by the aquatic organisms including bioaccumulation, metabolism, and biomagnification OC pesticides found (all units are in ng g–1 ww) in mayfly larval tissues included heptachlor epoxide (37), α-endosulfan (51), aldrin (54), DDE (67), dieldrin (100), β-endosulfan (150), endrin aldehyde (150), and endosulfan... la Cruz and Luisa E Castillo The influence of rice and sugarcane production on coastal aquatic ecosystems can be observed in Nicoya Gulf Pesticides generally used on these crops, e.g propanil, quinclorac, cypermethrin, oxadiazon, and ametryn, have been reported in surface water from the region (Table 12. 9) Pesticide residues reported in biota were primarily OCs, including aldrin, lindane, DDT and its... bivalves, and gastropods various pesticides used in rice and technicals imported to formulate 1998 Freshwater drainage system Arenal-Tempisque Pacific Table 12. 9 continued water sediment biota: invertebrates OC and various Water: pesticides used DDT: 0.5 µg L–1 in rice lindane: 0.04 µg L–1 Samples from drainage systems had higher incidence of pesticides © 2003 Milton D Taylor, Stephen J Klaine, Fernando... drift point aerial drift runoff, erosion non-point effluents point – some root crops are planted near coastal areas point fresh waters coastal waters terrestrial and ground waters DATE AND OIL PALM Pre-planting seeds: fungicides weeds: herbicides aerial drift runoff, erosion point occurs in lowlands at lower end of watershed near coastal areas continued… © 2003 Milton D Taylor, Stephen J Klaine, Fernando... research is needed to better understand the chemical fate, distribution, and effects of pesticides in the tropics and the consequences of their use and misuse on tropical aquatic ecosystems Special emphasis should be given to studies examining the potential impact on tropical aquatic ecosystems of repeated and continual low-level exposures to mixtures of pesticides Contemporary pesticides, e.g ametryn, cadusafos,... aerial drift runoff, erosion non-point aerial drift runoff, erosion non-point – takes place in lowlands at lower end of watershed near coastal areas point fresh waters coastal waters terrestrial and ground waters continued… © 2003 Milton D Taylor, Stephen J Klaine, Fernando P Carvalho, Damia Barcelo and Jan Everaarts 354 Elba M de la Cruz and Luisa E Castillo Table 12. 7 continued Production stage/ Biocide... runoff, erosion point Pre-planting land preparation: insecticides weeds:herbicides Post-planting weeds: herbicides Ripening acceleration: herbicides aerial drift runoff, erosion non-point aerial drift runoff, erosion aerial drift runoff, erosion non-point Production fungicides, insecticides biological control, rodenticides aerial drift runoff, erosion non-point planted in the middle and lower section... Klaine, Fernando P Carvalho, Damia Barcelo and Jan Everaarts 359 continued… The use of pesticides in Costa Rica 1995–97 Freshwater rivers and coastal lagoons, marine river mouth, sea outlet, and coastal waters Caribbean 360 Table 12. 9 continued 1998 Fresh water drainage system Arenal -Tempisque Pacific Substrates water in rice paddies and sugar cane fields Pesticide class Results Remarks propanil: 0.8... from 12. 8 kg a.i ha–1 in 1992 to 20.5 kg a.i ha–1 in 1997 (Chaverri and Blanco, 1995; de la Cruz, 1998) and is similar to the value reported for the Netherlands in 1991 (20 kg a.i ha–1) (Teunissen-Ordelman and Scrap, 1997) but higher than that of Japan (10 kg a.i ha–1) (WHO, 1990) The quantity of formulated products increased from 29.5 kg ha–1 in 1992 to 41.3 kg ha–1 in 1997 (Table 12. 4) Wesseling and . near coastal areas Pre-planting runoff, erosion non-point weed control: herbicides soil insects: insecticides Post-planting aerial drift non-point soil and stem insects: runoff, erosion insecticides Pre-emergence. plantation drainage systems, into river systems, and eventually into estuarine and marine ecosystems. Information on pesticide use in other business activities, e.g. aquaculture and salt production,. Cruz and Luisa E. Castillo PESTICIDE REGULATIONS Control of pesticide labeling and handling in Costa Rica is primarily the respon- sibility of the Ministries of Agriculture and Health. Pesticide