Uruguay -Current State of Chlorine Containing Pesticides in Uruguay

by Mr. Mario Boroukhovitch

Uruguay's economy is based mainly on livestock and agriculture, that represent today 10-12% of P.B.I.(Internal Gross Product)(12) The animal production (cattle and sheep meat, milk, pork, poultry) represent 60% of the P.B.I of this sector, and the other 40% correspond to agriculture production (rice, citrics, barley and other cereals, etc): Agriculture and livestock product and agroindustrial produce 37% of the full enter holding in the country for export concepts.

The agriculture and livestock production is affected by the attack of different pest, which produce important damage. With the proposal to diminish the incidence of this dangerous organisms, has implemented different control measures, and chemical control was one of the alternatives.

Like in most countries of similar characteristics, since the apparition in the world market of the organic synthetic pesticides, after the Word War II, Uruguay had used these products. Between this pesticides were the organochlorates insecticides.

At the end of the forties, it was used hexachlorociclohexane (commonly commercially named Gammexane) for the control of the swarms of locust (American Schistocerca = Schistocerca cancellata) and later the uses of other chlorate insecticides for control of local locust named "tucuras" (Orthoptera, Acrididae).

The extensive use of chlorate pesticides in the sixties was for the insect control, mainly lepidopterous worms in cereal crops (wheat, barley, oats, corn, sorghum), oilcrops (flax, sunflower), industrial crops (potatoes, sweetbeet), and for soil insects and cutting ants control. Also part of the farmers used organochlorates insecticides for control of pest in vegetable and fruit crops.

In the livestock area, it was used some chlorate pesticides for ectoparasites control.

National Authorities perceiving the risks that can produce the wide use of the organic synthetic pesticides in the agriculture, could produce, intended to minimize their risk throughout the technical advice to the farmers who used these pesticides. In 1958 a supervised control service was established, and the main goal was to avoid unnecessary wide applications of this pesticides. For this reasons the Campaigns of locust control were transformed to "Campaign of the fight against caterpillar and others pest insects"

This Campaign had an Aerial Service Department with area applicant aircraft that make aerial applications only authorized by official entomologist and farmers technicians.

The main organochlorates insecticides first used in this Campaigns were DDT and endrin in aerial sprays , but others products as toxaphene, toxaphene-DDT, dieldrin, telodrin.

By inspections solicited by the farmers, the entomologists of the Livestock and Agriculture Ministry (M.A.P.) Plant Protection Department especially assigned to the "Campaign of the fight against caterpillar and others pest insects", determinated in each situation the necessity or not for proper control measures. For such aspect as vegetative phase of the crop, type and amount of damage, density of the pests, development stade of the insect, distribution in the crop, presence of natural enemies (parasites and predators) and its incidence, and attacks places in the crop were evaluated.

Likewise, the technician determinated if were necessary make local 0 total treatment in the crop, type of pesticide to use, doses and total volume of spraying for ha, especially in the aerial applications.

In this manner, it could diminish the treatment at only 30% of the total area inspected (2), which is showed in the table VI.

This activity of technical assistance at Official level, made by the Plant Protection Department (further on Plant Protection Direction) in the eighties was transformed in a monitoring service in extensive crops, making advertences about the appearance of insect pest. This information was noted by technicians and farmers and used for make decisions for pest control. This monitoring work was extended as advertences about appearance of fungal diseases in winter cereals (rust, fusarium, septoria and other phytosanitary problems).

In 1968, in account the knowledge of the problems of bioaccumulation of chlorates pesticides in the lipids of animals and the men, raise general preoccupation to protect the national consumer, but at the same time make not affect the meat and derivades exportations. The Uruguayan Government decree 367/68 empowered at the Livestock and Agriculture Ministry to regulate, and in the necessary cases ban the application and destination of the pesticides of use in livestock and plant protection, when it consider dangerous to public health.

By Livestock and Agriculture Ministry Resolution dated 6/6/968 was banned the use of chlorate insecticide formulated with aldrin, dieldrin, endrin, chlordane, heptachlor, gamma isomer of H.C.H., DDT and endosulfan, destined to the control of insect pest in grassfield and implanted and/or artificial prairies. It was excepted the use of chlorinated insecticide for ant control in focussed treatment.

All the registrants of this insecticides must add in the labels the phrase "Its must not use in grasslands implanted and/or artificial prairies".

Other problems that general concern, no only of the plant protection view, but of the consume population, because can repercute in the human and animal health, was the insect control of stored grains.

In 1973 was created in the Plant Protection Research Center and Direction, a Department of Stored Grain that realized a survey of the problem and developed a Campaign to control insects in stored grain, recommending cleaning in treatment of the storehouses and storing locals and the use of the adequate protestant insecticides. In this recommendation was eliminated chlorated insecticides for all the treatment in structures, empty bags and vehicles, authorizing only their use for seed treatment.

Parallel it was started a Program of Grain management, avoiding quality and quantity losses, and diminish presence of micotoxines, and make inadequated the life conditions to pest.

It was stated in the different inspections, that in the years that the climatic conditions owed to reduce the sowing areas of cereals (wheat, oats, barley, etc) the stored seeds treated with chlorates pesticides were mixed with cereal grain and destined to human and animal consume.

View the difficulties in this moment to make analytical determination of residues of pesticides in 1977 with the promulgation of decree 149/977 dated, march 15, 1977 yet today in force was included banning chlorate insecticides not only in grassland and prairies, but also in grain treatment destined for human and or animal consumption and/or industrialization.

After the Committee for the study of biological residues in meat at National level carnation in 1979, the analytical laboratory of the Veterinary Research Center Miguel C Rubino, collaborating with agronomic area were analyzed different wheat and rice grain samples extracted by technicians of Plant Protection Direction (4).

Similar activity was realized by the Technological Laboratory of Uruguay (L.A.T.U). The results of this analysis area showed in the tables VIII, IX, X and XI.

In the same period, and with the creation of the Toxicological Information and Advice Center (C.I.A.T.) of the Clinics Hospital (University of the Republic), for agronomist and medical initiative was developed an agromedical team integrated also with veterinarian and chemicals technicians. Working jointly one of the task of this team was to evaluate to organochlorates pesticides contamination in Uruguay to determine the chlorate level in the blood of exposed and don’t exposed professional way population (5) The conclusions confirm that exist certain grade of organochlorates residues in the general population. (Table XIII)

The exposed population presented higher levels that the no exposed one. Residues did not concord strictly with the pesticides in use at that moment, but reflected a greater grade of exposition, the logical consequence of years working with different organochlorates (14) HCB levels, product used for seed treatment of diseases in wheat and other cereals, may be owing a use deviation of treated seed that were incorporated at human or animal consumption, violating the legislation at that moment (14). In the dieldrin event, the residue values can be explained more for domestic use or a deviation of agriculture use to household.

It attracted the attention the appearance of important residues of DDT, since Uruguay did not import this product for agricultural use after 1977.

This activity was continued and in 1982 the conclusion and result were founded in the paper Clinical and analytical control to an organochlorates pesticides exposed population.

Of the results can be concluded that organochlorates impregnation values descended in the lapse of three years in people with initial high, medium and low values, and descend at the mid founded for no exposed populations in many cases (See table XVI). The presence of these organochlorine levels in blood showed an impregnation without clinical or paraclinical repercussion in those three years. The most used insecticides in those moment - endrin and endosulfan - don't leave residues because they have a quickly metabolization.

It was detected metabolites of others chlorates pesticides which were used in agriculture in these moment. Also existed interest in research in motherly milk. In this area can be mention the paper* Pesticides organochlorates residues in human milk*(7) in 1985. In all the samples were founded BHC, beta HCH, DDT and their metabolites (ppDDT y ppDDE) and dieldrin at different levels. They didn't detect polychlorinated biphenyls (PBCs).

These results indicate that the use deviation of many organochlorates of agricultural use to domestic use, the food contamination, especially treated seeds that deviate at human or animal consume and organochlorates domestic insecticides, are the reasons for the detected contamination.

An other paper "organochlorates pesticides residues in umbilical cord blood": Comparation with maternal level"(14) was detected in the most of the samples of blood mother HCB, beta HCH, dieldrin and DDT and its metabolites residues.

Legal Restrictions and Prohibitions of Organochlorates from 1977 to Present

The Ministry of Agriculture and Livestock based in the recommendations of the General Directions of Agronomic and Veterinary Services for Legal Resolution date 1/12/977 banned hexachlorociclohexane importation, manufacture, formulation and sale for agricultural and veterinary uses. This action was the consequence of deviation use from agricultural to veterinary. It is excepted for this banned lindane (99% gamma isomer of HCH).

By Legal Resolution of Plant Protection Direction dated May 19, 1988 the registration and sale authorization of endrin was revoked, for all agronomic use, except parakeet control (Myiopsitta monachus, Aves Psittaciformes), only been sale with official authorization from Plant Protection Direction and no less 20 liters containers. In account to endrin high toxicity to man, animals and the environment, and in view that existed other actives to substitute them, was limited its use. The parakeet control consists in endrin introduction in the next entry.

In March 29 of 1989,by Plant Protection Direction Resolution all the organochlorates pesticides used in seed treatment were revoked. This included benzene hexachlorate (HBC) used many years ago for your fungicide action in seed treatment. The HCB residues were detected in exposed and no exposed populations at organochlorates pesticides, before mentioned.

For Plant Protection resolution dated September 22 of 1989 was revoked the register and sale authorization of chlorate insecticides, permitting its use only for cutting ant control with an active concentration less than 2,5% p/p or p/v., colorless in red and it has to be more than 1 liter o 1 kg.

In Uruguay the cutting ants on special Acromirex and Atta are a very big problem for many crops because of the serious damage on them.

Other similar study performed in Rio de la Plata and programme of monitoring and control on Uruguay River was published in 1992 by Chemical Engineer Juan Miguel Moyano Recine in its paper "Pesticides residues in rivers and seas" (13) and the results of organochlorates in Uruguay River showed in the table XXII.

Also is necessary to distract the inform realized by consultants of the Programme of the Environmental National Study in the orbit of Presidential of Republic, with the support of BID and OEA*.

The agreement between Ministry of Transport and Public Work and the University of the Republic, through Hydrographic Direction and C.I.A.T. started pesticides residues studies in the Basin of Santa Lucia River had the objective to obtain information about pesticide use and management in the Basin. In 1989 an inquiry was made of farmers and applicators. There are a paper about this, named "Pesticides on environment Risk criterion"(9). The Rio Santa Lucia Basin is one of the potable drinking water source to Montevideo and Canelones population.

Elimination Problem with the Organochlorates Pesticide Lots

It doesn't exist a survey of finished or used lot, we know puntal situations of lots of chlorated insecticides stored in sure locals. The elimination solution was burned in special incinerator ovens with temperatures over 1200 centigrade grades. In first instance it was thought to use the incinerators of cement manufactures that operate in Uruguay, but have big difficulties for elimination of solid residues and don't overtake the temperature mentioned. and it is necessary search alternatives others.

Discussion about the Problematic of Chlorated Insecticides in Uruguay

As other countries in the world, use of chlorated insecticides in Uruguay was ample, since their entry in the market, at the end of the forties.

The diffusion of scientific evidence that showed adverse effects of this chemicals to man, domestic animals and environment, carry on the Uruguayan Government, at initiative of Ministry of Livestock and Agriculture, by decree 367/968 to authorize at those Ministry to regulate and to ban, when it is necessary, those livestock and agriculture pesticides, when it consider threat for human health. Based in this normative, was resolved use prohibition of chlorates insecticides to control insect that attack grasslands, and implanted or cultivated prairies. In account the high incidence of cut ants in this pasture fields, is permitted localized nest control of these insects. The regulatory action obliged to intensify the use of others actives, organophosphorous and organocarbamates, but also the use of microbiological insecticide Bacillus thuringiensis, registered in Uruguay at middle sixties, but being more expensive that other insecticides.

The substitution of chlorates to organophosphorous and carbamates insecticides provoked a higher costs in control treatments, in some circumstances higher risk of intoxications and the necessity of realize different experiments for control insects. Nevertheless this actions started chlorinated substitution process in others crops, and the news to the farmers of practicable alternative products.

By Plant Protection resolution dated November 22 of 1989 it were clarify that the before revocation mentioned excepted endrin and endosulfan.

Finally, by Ministry Resolution date on September 23 of 1997, all chlorate pesticide register were revoked, except endosulfan and dodecachlor This last product formulated like 0,45% granulate toxic bait.

Of this manner culminate a restriction and prohibition proceeding of this COPs, restricting the revision of dodecachloro. The reason for no prohibited dodecachlor is due that in Uruguay the farmer have preference use for the granular toxic bait in ant control in fruticulture, horticulture, floriculture and mainly forest cultures. The others toxic granules registries haven't the same efficient control, according the farmers opinion.

Imports Statistics of Organochlorates Insecticides in Uruguay

In Uruguay, with exceptions, pesticides for veterinary or agronomic use are not manufactured here. Most of the products area already formulated auxiliary substances are imported for a local formulation.

Each one of the imported shipment that is imported, is analyzed by the laboratories of the General Direction of Agronomic Service and if the analytical results are coincident with the official registration is liberated by custom authorities. General Direction of Agronomic Services has an actual statistical information in this field since sixties( 1,3).

At this respect, except dodecachloro and endosulfan, the last shipment of chlorates imported was aldrin, power formulation 2,5%(830 kgs a.i.), in 1991.

Tables I, II, Ill, IV and V show the importation evolution of organochlorates insecticides in different periods, and the comparative volumes of the others insecticides groups.

Pesticides Intoxications Statistics

The Toxicological Information and Advisory Center (C.I.A.T.) had elaborated annual reports that include different types of intoxication statistics. In the paper "Chlorates insecticides intoxication"(l0) we reproduce in the tables XIX and XX the consult about chlorates, according of intoxication type, ingress way and age, between December 1975 and October 1978.

The most chlorated intoxication is by accidental ingestion in children of suicide intent. The labor intoxication is few.

In the Environmental contamination area, there are information about river contamination as is showed in the papers "Presence of organochlorates pesticides in exterior Rio de la Plata an Maritime Front (11), 1987. The result is showed in the table XXI. All the amounts respect to aldrin, dieldrin and DDT exceed established limit to aquatic life, but all the values are lower for human health criterion.

The initiating campaign to control insects that attack stored grain, in 1973, was the opportunity to rationally the use of preservative and curative insecticides, eliminating chlorated insecticides use as structural treatments and avoiding use deviation to treat directly stored grains destined to human and animal consummation.

At this respect, in the opportunity of study the regulations about registry, importation and sale authorization of agriculture pesticides, incorporated the use prohibition of chlorated to treat grain destined to human and animal consummation and for industrialization. The obligation of colorant add to treatment seed formulation, limited yet more deviation stored seeds at human or animal consumption. Subsequently, the chlorated seed treatment ban, eliminate of fact the use deviation of seed to consume.

After, the use restriction of chlorates insecticides only for cutting ant control, is other stage of the restrictions process of this products and the use of others actives, as phosphorous, carbamates and pyretroids insecticides, with similar effectively, but without the chlorates problems. This chlorate restriction imply that maximum concentration must no high than 2,5%, only for ant control, and must be identified the chlorate formulation with adding colorants for easy identification in the situation of deviation of use.

The use restriction of endrin, only for parakeet control, eliminate a insecticide, that its effective is the high threat, and its accumulative action is lesser than others chlorates, its environment impact and its toxicity made inadequate its use, having adequate substitutes, except for parakeet control.

We need to add at all the mentioned actions the chlorate monitoring residues in stored grains destined to internal consume as well exportation, the meat monitoring residues and some evaluations made by analytical laboratories of the Plant Protection Direction in certain fruits and vegetables that commercialize in the major center of Uruguay, Model Market, has rendered to conclude that chlorates residues do not create threat to consumers and the environment. In the practice, since 1991, except dodecachloro and endosulfan were no import chlorate insecticides.

Finally with the prohibition of chlorated insecticides (except dodecachlor and endosulfan) by Ministry Resolution dates September 23 1997 culminate regulatory actions of this POPs that initiated in 19687 with the chlorated insecticides ban in grasslands and prairies.

Today 1998, only are authorized endosulfan and dodecachlor, the first without the problems of the group. Formulation authorize of dodecachlor is granular toxic boat with 0,45% of active ingredient for control cutting ants. This type of formulation it is choose by the farmers for ant control in fruticulture, horticulture, floriculture and mainly forestall cultures. This is because the farmer saw the toxic bait granule in the ant ways to nest, and the ant’s charge it and introduce the toxic in the colony. The others products are formulated like dusts and concentrates and to imply it, to have to search the nest, and to introduce the product, being more difficult and expensive.

In Uruguay they are others toxic bait granules registered at sufluramida and phenil pirazol, but this products do not conform many of the farmers, whom continue using dodecachlor.

Today, dodecachlor is in revision and study for Plant Protection Division of the General Direction of Agronomic Services takes in account others alternatives. Some farmers differ with dodecachlor ban, and they argue that the quantity of toxic bait granulate applied is very few for ant nest to contaminate the environment and they wish to wait until found others substitutes of the same efficient control than dodecachlor.

In relation to a soil treatment, actually it is used chlorpirifos, diazinon or carbofuran for example with the same effectively than chlorate insecticides.

With respect a parakeet control, the substitution of endrin by carbofuran, do not lessen toxicological threat to applicators and environment, because the used formulations (flowable 40%) is the high toxicity and no selective.

In the agromedical area, the survey of organochlorates pesticides realized in exposed and no exposed populations and studies in mother's milk and cord umbilical blood had detected the problematic, and were the basis for take restrictive an ban actions.

The intoxication statistics indicate that labor intoxication is limited. In the environmental area it is where the effort had been less incentives, but there are papers that show the presence of pesticides residues in rivers, but there are not consequence of national management, because the rivers are binationals and trinationals and the chlorates residues can be origin of neighbor countries and no only from Uruguay.

The relative recent creation (10 years) Ministry of Dwelling, Territorial Ordering and Environment Media, would permit, take new measures with a national regulations that will permit increase this actions.

References

l. Boroukhovitch M. 1973, Reseña sobre Insumos de Insecticidas en Uruguay para la Agricultura. Primera Reun. CIPA -COPANT Plaguicidas - Residuos de Plaguicidas Buenos Aires.Doc RTE/5/2/ 10

2. Boroukhovitch M. 1978, Manejo de Plaguicidas y Preservacion del ambiente. Rev. As. Uruguaya de Seguridad, Montevideo

3. Boroukhovitch M y Llanes E 1982, Breve Reseña sobre Estadisticas y Empleo de Plaguicidas Agricolas en Uruguay. Congreso Seguridad e Higiene en el Trabajo. As. Uruguaya Seguridad Paysandu. Uruguay

4. Boroukhovitch M. 1988, Algunas Acciones Realizadas a Nivel de la Direccion General de Servicios Agronomicos en Relacion con Contaminantes en Alimentos. Primer Seminario de Ecotoxicologia/Soc Uruguaya de Toxicol. y Ecotoxicologia Montevideo 29/30 abril 14 pp Montevideo

5. Burger,M,de Barbino J.P.,Schonbrod P,Decia C,Boroukhovitch M and Antonaz R. 1980. Niveles Sanguineos de Plaguicidas Organoclorados en Uruguay en Adultos Expuestos y no Expuestos. Libro Resum. Soc. Uruguaya Toxic. y Ecotoxicol. So Congreso Latinoamericano

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