23. Precautionary Principle and Potential POPs: the Chilean Case

by Ms. María Elena Rozas

The increase of industrial activities that imply the discharge of persistent toxic industrial chemicals into the atmosphere and the sustained and intensive use in agricultural and forest activities made in Chile for more than four decades, of pesticides identified as Persistent Organic Pollutants (POPs) by the United Nations Environment Programme (UNEP) (1), as well as other potential POP pesticides, (2) have caused contamination of terrestrial and aquatic ecosystems, damages to the marine biota and to the wildlife, and various disturbances in the health of the exposed workers, as well as contamination among the general population, through food and maternal milk.

This facts have been pointed out by several studies done in the late seventies and mainly the eighties, (3) that were decisive in the issuing of a resolution by the Ministry of Agriculture in 1977 that banned the use of the DDT in pastures and related cultivations, and another in 1983 which imposed restrictions on DDT, aldrin, endrin, chlordane and heptachlor, prohibiting their use in pastures within the country's IX and X regions (La Araucanía and Los Lagos), and in all vegetable by-products susceptible of being used in bovine feeding. (4)

However, this resolution was not accepted by a great majority of farmers, who continued the intensive use of DDT and of other chlorines. This was verified by the Ministry of Agriculture and the Ministry of Health through soil analysis and the study of DDT residuals in cow milk and in maternal milk. This motivated, along with other causes, the total ban on DDT and the drines in the eighties.

The present regulatory status in Chile of the 9 POPs pesticides, contemplates a prohibition to import, commercialize and use DDT, (Res. 639/84), dieldrin, endrin, heptachlor and chlordane (Res. 2.142/87) and aldrin (Res. 2.003/88). As for mirex, hexachlorobenzene and toxaphene, these products were not registered in the files of the Servicio Agrícola y Ganadero (SAG), dating only from 1985. No information previous to that date exists either, because registration of pesticides was non mandatory in Chile due to the absence of a regulation.1984 regulation put an end to a three years situation of total license on that respect.

Although these pesticides are not registered in the official files, they have appear in organisms and in maternal milk, accumulated in concentrations that surpass national and international maximum limits allowed.

Studies conducted in the town of Río Negro, X Region, for example, showed DDT concentrations in maternal milk as high as 12.287,30 ug/kg of milky fat. (5) Organochlorine residuals found in animals in the IX and X regions surpassed the norm up to 50 times.

Although most of these pesticides have been restricted or banned in Chile for a good number of years, the vast majority of the studies made until now in regions of high consumption of organochlorine pesticides (OC) demonstrate that, either for their high persistence or their clandestine use, these chemicals are still present in living organisms and in the environment.

Soil analysis made between 1982 and 1984 in central Chile, where the most fertile lands are found, showed that the valley of the Aconcagua river and the coastal sector of Puchuncaví, presented the highest pollution in the whole country, as well as the widest range of organochlorine residuals in the soils. In the valley of the Aconcagua the occurrence reached a 100%, presenting pp'-DDE, pp-DDT, dieldrin, endrin, and heptachlor residuals. The ubiquity of DDT indicated a massive use of that chemical in the region. (6)

Later soil studies done between 1987 and 1989 detected again a larger occurrence percentage in northern and central Chile, decreasing toward the south. The VI Region, with one of the richest agricultural soils in the country, presented 84% of organochlorine residuals. A full 70% of the samples presented pp'-DDE residuals. The studies also detected the presence of dieldrin, aldrin and lindane. In the VII and VIII regions the occurrence of OC reached 71% and 70%, respectively. Dieldrin, pp'-DDE, lindane and chlordane were detected in the first one, and lindane, dieldrin, heptachlor-epoxide, aldrin and pp'-DDE, in the second.

Similarly, residuals of lindane, dieldrin and pp'-DDE were detected in southern Chile. The IX Region (La Araucanía) was the area that presented less OC contamination, probably because it`s an area of indigenous settlements. In the X Region (Los Lagos), pp'-DDE, lindane, dieldrin, DDT and pp'-DDT residuals were found in almost 80% of the samples, indicating that at the time of the study (1989) the ban on the use of DDT was not respected in this region. (7)

While the presence of organochlorines in the soils of some southern regions of the country was diminishing, as is the case of the Los Lagos Region, where only four residuals were identified, and aldrin, chlordane, endrin, heptachlor and heptachlor-epoxide were not detected, their presence in high concentration persisted in living organisms. The analysis of a total of 540 samples of maternal milk belonging to mothers from the provinces of Valdivia, Osorno and Llanquihue showed that a high percentage of the samples surpassed by far the maximum limit allowed by national and international standards. Although dieldrin and DDT had a minimum presence in soils, in maternal milk the following pesticides appeared: hexachlorobenzene (HCB), alpha and beta benzene hexachlorohydrate (BHC), lindane, heptachlor, heptachlor epoxide, aldrin, dieldrin, and DDT and its metabolites. Regarding DDT, the investigation concluded that "this pesticide continues to be a serious problem from Río Negro to the south". (8)

In this region the daily intake of pesticides surpassed excessively all standards, to the point of being described by specialists of the health sector as "frankly worrying", specially for the possible toxic effects on the breastfed population. It may be pointed out that in this region the occurrence of organochlorine residuals in soils corresponds to the national tendency, with a value close to 55%.

A study of maternal milk carried out in 1990 in the Metropolitan Region, (Santiago), detected the presence of metabolites of DDT and lindane in all the samples; 44% of the samples belonging to high socio-economic strata surpassed the 50 ug/kg. Lindane, on the other hand, had a bigger presence in the samples belonging to low socio-economic strata, probably due to a bigger use of the chemical by the Ministry of Health in the control of the scabies and pediculosis. (9)

On the other hand, research done on food in different regions detected residuals of the organochlorines lindane, aldrin, endrin, dieldrin, heptachlor, DDT and its metabolites, surpassing the standards, in dairy products, meats and cereals. A program of surveillance of chlorine pesticides made by the Ministry of Health between 1982 and 1987 in 3.234 samples of foods, detected that 20% of them was above the allowed maximum limit.

Later studies made by the Institute of Agricultural Investigations, between 1987-1990, with samples of foods obtained in supermarkets of Santiago, continued to find residuals of organochlorine pesticides in almost every product analysed. Excesses of these chemicals according to the standards settled down by the Codex Alimentarius, were detected in 23% of the samples of meat of bovine origin. In wheat flour, for example, there was lindane, aldrin, dieldrin, DDT and chlordane, while in bovine meat fat the most frequently found pesticides were lindane, heptachlor-epoxide and dieldrin. (10)

In southern Chile, researchers of the Instituto de Medicina Preventiva Veterinaria y del Centro Tecnológico de la Leche, at the Universidad Austral, carried out studies on residuals of organochlorine pesticides in livestock from the X and XI regions. The results were published in 1986, and indicated that 90% of the samples presented residuals of DDT surpassing the allowed maximum limits. The compounds found in the meats were: methoxychlor, hexachlorobenzene (HCB), DDT, aldrin, lindane, benzene hexachlorhidrate (BHC), heptachlor, chlordane, endrin, dieldrin and mirex. Since 1985 the last one appears as not registered in the country. These eleven residuals, of a detected total of twelve, were found in concentrations of 10,25 and up to 50 times over the allowed maximum limits. As for DDT, of the 500 samples that were analysed, 447 presented residuals, proving that, in spite of the ban, this was the most frequently used pesticide in that region. (11)

Another study carried out by the Universidad de la Frontera in the years 1984 and 1986, in bovine males and females, discovered the presence of DDT and its metabolites in both periods. From the analysis of some animals examined in 1986, it was deduced that those bovines had been exposed to DDT that very same year, that is to say, when the ban was already in force. (12)

Until a few years ago there was the presumption that the banned pesticides included in the lists of 12 POPs were still in use in Chile. The basis for this assumption were the following:

- the results obtained by most of the above mentioned studies;

- public advise given by some experts on agriculture and forestry who still disregard legal resolutions and continue to recommend the use of chlorine pesticide through the pages of specialized journals (13);

- confidential statements made by farmers who declared to have use DDT, aldrin and other banned organochlorines because of their negligible price and their wide spectrum.

These suspicions have been confirmed recently by two different ways:

- A study carried out by the University of Talca (14) with information on pesticides used in that region, provided by the agricultural companies themselves, through their executives, that indicates that the following chlorine pesticides were in use in 1995: acarin 25WP, acarthane, kelthane AP, kelthane EC 185 and aldrin 25%.

- Two cases of acute intoxications caused by aldrin (banned in Chile since 1988), notified by local health services in 1997, a woman from the Region del Maule and a man from the Region del Bío Bío, are the evidence that support the results of the investigation made in Talca, and indicate a frequent use of the banned pesticides in an extensive area of the country. Such informations show only the tip of the iceberg, one of the many aspects of a much bigger problem, concerning obsolete stocks or illegal internment and traffic.

As for the polychlorinated biphenyls (PCBs), their main use is in transformers and capacitors. Dioxins and furans are found in pesticides that contain these pollutants as non-deliberate by-products. Also industrial activities such as the installation of new thermoelectric power stations, (e.g. Central "Guacolda", in the valley of the Huasco river, in the north); the new boom of investments in the forestry sector, where herbicides like the 2,4-D and pentachlorophenol are used in the plantations; the enlargement of cellulose plants and the construction of new ones (e.g. Celulosa Arauco, at the Bay of Mehuín, X Region); the current operation of chemical industries that present serious breaches in security (15) and the frequent accidents in chemical industries (16), all these are sources that generate dioxins and furans, increase the concentrations of these pollutants in the environment and the subsequent risks, representing a threat to health and to the ecosystems.

In spite of all this and also in spite of the quick process of industrial growth, there is no regulation in the country for these pollutants, nor a cadaster of PCBs. Therefore it is impossible to know the existing amount of these chemicals, nor the places where they are discarded. A part of them is voluntary exported through the Agreement of Basle, but there is no solution at the moment for the remaining chemicals that keep accumulating in the country. This is due to the fact that there are no treatment facilities nor places of final disposal of these pollutants.

These are clear and objective indicators that we are dealing with a problem of big environmental, economic and public health impact that will worsen increasingly with time and will become an enormous economic load for the State and the population in general.

Although studies of chronic intoxication associated to pesticides are scarce in Chile, some preliminary discoveries are extremely worrying. All the studies carried out in areas of intensive agricultural activity and of massive and indiscriminate use of pesticides, especially in the VI Region (Rancagua) and the VII Region (del Maule), have thrown results indicating a serious deterioration of the health of their inhabitants, with an increase of pathologies associated to the use of pesticides. Among these are major multiple congenital malformations, congenital cardiopathies, spontaneous abortions and cancers.

Ever since the agricultural exportation activities intensified, there has been a clear and alarming increase in major malformations in the Region of Rancagua. Studies carried out in 1988/90 detected a prevalence of major multiple malformations of 3,6 per 1.000, very much above the national average of 1,93 per 1.000 in the same period. (17) All the cases analysed in these studies corresponded to children of "temporeras" (women working in the recollection and processing of fruit) and to people that were exposed to pesticides.

According to the studies the rate of defects of the neural tube (acraneum, myelomeningocele and hydrocephaly), is three times higher than in the rest of the country, and the rate of stillborns with malformations, 211,1 per 1.000, duplicates the rate of the Clinical Hospital of the University of Chile, in Santiago, of 120,6 per 1.000.

Another study made later on, in 1994/95, by the Gynaecology Service of the VI Region revealed that congenital malformations are the first cause of neonatal death. Researchers detected that 34,2% of the deaths occurring in the first 28 days of life were caused by congenital malformations. (18)

Similarly, a study carried out in 1996 by the Unit of Neonatology of the same region, concluded that 25% of the deaths of newborns assisted in that unit corresponded to congenital malformations.

On the matter of spontaneous abortions, an investigation carried out in 1993, in local hospitals as well as in the regional hospital of the VI Region of Rancagua, determined that in the period covered by the study, the proportion of spontaneous abortions/births, in relation with the national level, was bigger than the expected 10%. (19)

Another study in this same region, in a highly rural predial area, Pichidegua, producer of seeds and dedicated mainly to industrialized agriculture, under plastic covers, detected a significant incidence of spontaneous abortions and congenital malformations, even higher than that of other counties of Rancagua. The investigation used the death certificates and the hospital expenditures of the county as source of information and concluded that the condition of rurality and the exposure to agrotoxics revealed higher rates of spontaneous abortions and mortality due to congenital malformations.

The study presents a statistically significant difference in spontaneous abortions regarding other counties of the region. Since spontaneous abortion is one of the effects that be detected early, the results of the study are highly worrying in relation to what the future can bring in matters of medium or long term chronic effects, such as congenital malformations and tumors. (20)

In the VII Region, where there are also intense agricultural and forestry activity, in 1993 and 1994 there was an average of 45 children born with congenital malformations, a number considered by the Hospital Director, Dr. Norman Merchak, as a high occurrence. According to him, "almost all the parents of these children had been exposed to pesticides, since they worked in fruit orchards, in packing plants, or lived near these places". (21)

In the same way, cardiologists of the Calvo Mackenna Hospital, Unit of Cardiology, in Santiago, a specialized center that receives patients from all over the country, have detected that approximately 70% of the newborns that present congenital cardiopaties do come in fact from the VI and VII regions. (22)

Despite the existing regulations, South American countries present important holes in their legislation, lack of political will, precarious resources for inspection, and inadequate cultural, social, climatic and economic conditions. All these factors make it impossible to insure a rational handling of chemicals and a safe use of pesticides.

The contamination of the ecosystems, with the subsequent reduction of animal and vegetable life and health and environmental problems that affect South American countries that use the 12 POPs and other potential POPs, prove that the governments and the industrial and managerial sector have not been capable of avoiding the impacts of persistent organic pollutants on health and the environment and that they are equally unable to reduce the risks provoqued by the uncontrolled liberation of these pollutants into the environment.

In front of this serious situation it becomes necessary, therefore, to reach an international agreement on POPs that incorporates and adopts, urgently, the following approaches and measures:

- A special consideration, by the negotiating parts in the Global Convention on POPs, of the concerns and necessities of the poor, developing countries, with enormous economic inequities. In this sense, technical and financial assistance for the reduction and elimination of stocks and a better administration of obsolete and out of use pesticides and POPs chemical substances are a top priority.

- The acknowledgement of all the involved actors, especially the weakest, in the negotiations leading to the global convention on POPs, with the purpose of assuring the wide participation of the whole society in the adoption of the environmental decisions, particularly those referred to persistent organic pollutants.

- The prohibition and reduction of production, generating sources and emissions of PBCs, dioxins and furans to the environment. Considering that these measures are gradual, a first step would be to assure a rigorous and environmentally appropriate managing of the use, storage and final disposition of these polluting residuals.

- The reiterated use, in countries of the Southern Cone, of chlorides banned by national legislation, demands the total and global banning of the production and use of POP pesticides. With regard to DDT, still used in some regions for the control of some vectors, it becomes necessary to make combined efforts contemplating technical and financial support, by the industrialised countries, for the implementation of international campaigns dedicated to eradicate these vectors through the use of non-chemical alternatives that will insure an efficient ecological handling of plagues.

- With the purpose that the agreements to ban or reduce the emissions of POPs have full legal force it is necessary to establish a global, legally bonding instrument for Persistent Organic Pollutants (POPs).

Most of the organochlorine pesticides in the list of 12 POPs, are not commonly used or have been banned in Chile; however, they are imported in big volumes. There is also a frequent use of other potential POPs pesticides which are the cause of special concern in matters of health and the environment. Such is the case of pentachlorophenol, lindane, 2,4-D and dicofol.

A study on pentachlorophenol (PCP) carried out in 1987 showed that a 100% of the workers presented symptomatology and clinical alterations compatible with exposure to the PCP. This was valid even in those cases with the lowest values, 0,88 and 0,2 in blood and urine, respectively. Thus, the study concludes that "the biological limit should be lower than these values".

Among other damages the workers presented skin and mucosae injuries, neurological and digestive dysfunction, weight drop, associated to anorexia in 50% of the cases. (23) Another study, carried out with 100 forestry workers, concluded that a 100% of the exposed men had urine and plasmatic values of PCP over the detection limit (0,03 mg/l). A 63% of the exposed workers surpassed the Biological Exposure Index (BEI) for plasmatic PCP, and a 58% surpassed the BEI for urine PCP. The prevalence of symptoms was as follows: Neuralgia (47%), inflammation of the mucousae (43%), abdominal pain (29%) paresthesis (29%) nausea (23%), diarrhea (12%), dyspnea (10%), constipation, (7%) and dysuria (7%). (24)

As for sharp intoxications, in the last two years two workers have died intoxicated with pentachlorophenol. One of them was a 16 years old boy who worked "preparing" pentachlorophenol to apply it later to wood, in a forestry company of the Region del Maule.

In relation to the 2,4-D, laboratory studies have demonstrated that it acts as a major depressor of the immune system, causes alterations in the reproductive system, has mutagenic effects in vegetables, animals and human cells, and accumulates in fatty tissues. However, since it has been classified as moderately toxic for acute effects, is broadly used in air fumigations in forestry sectors, causing serious impacts in the environment, in the people and in the neighboring cultivations.

This situation is extremely serious if we considered the absence of regulations for air fumigations, and the fact that the item of herbicides in Chile - and also in other Latin American countries - represents the higher volume in pesticide imports in the country (6.682 tons in 1997, of a total of 14.384 annual tons imported). In relation to herbicides, no analysis has been made nor a proper evaluation has taken place in this respect. Nevertheless, it is highly probable that in regions of intense use of pesticides, there will be contamination of superficial and underground waters, with negative consequences for the marine and terrestrial ecosystems and the subsequent risks to the health of the exposed communities.

Although health hazard due to the exposure to pesticides of the population in general, as well as occupational hazards conform a serious public health problem openly admitted by the authorities and specialists of the health sector, regrettably, their real present and future magnitude is still ignored. As example, most of the cases of acute intoxications are not notified to the local health services. According to studies, for each notified case there are four unnoticed, and in some regions the proportion can be as higher as 10.

Such it is the case of a serious accident with pesticides that took place on August 25, 1994 in the port of San Antonio, V Region. While containers with approximately 400 kilos of dicofol (organochlorine) and diazinon (organophosphorate) were being unloaded from a ship, a fire began and numerous workers and firemen were affected by the fumes. However, four workers, who were not evacuated promptly, suffered serious damages to their health. After the acute initial effects, such as vomits, strong headaches and other symptoms, the workers, 37, 39 and 50 years old, gradually began to present serious health problems. So far two of them have died from illnesses associated to exposure to organochlorine and organophosphorated pesticides: one from arterial hypertension and cardiac arrest, and the other, from bronchopneumonia and cerebral lymphoma. A third remains in a state of disability due to mioclonic dystony associated to these pesticides, according to the neurologist in charge of his treatment. (25)

In spite of the seriousness of the accident, there has not been a follow up of these cases by the appropriate sanitary authorities, nor were the four worker taken up and evaluated in their opportunity by the corresponding occupational health service (Instituto de Salud del Trabajador). As a matter of fact, they had to resort, independently, to the private health sector.

Up to now the efforts have been centered in reducing or eliminating the liberation to the atmosphere of a certain group of 12 persistent organic pollutants (POPs). However, the increment of the production, import and use of potential POPs, such as 2,4-D, endosulfan, lindane, pentachlorophenol, dicofol, pichloram, --pesticides that have demonstrated, in laboratory studies and in epidemic surveillance carried out in different parts of the world, to affect vital systems that ensure the survival of the species, such as the endocrine, immunologic and reproductive systems; pesticides whose use has been banned or severely restricted by different governments-- implies the continuation of impacts in health and in the environment in those countries that had already banned them, as well as in those who are still using the pesticides. This is due mainly to their quality of persistence, their capacity to bioacumulate and to deposit in places distant of those where they were originally applied.

The evaluation of these risks can be a decisive approach in the decision to add these pollutants to the current POPs list. It is not reasonable, specially for poor, undeveloped countries without financial or technical means for special studies, to wait until they are able to demonstrate clearly the cause-effect relationship, because it could be too late. In this case, the high economic costs of the pollution of waters, soils and organisms and the damages to health, externalized by the companies that produce and use these persistent pollutants, will continue to be assumed by countries with scarce resources and by the affected persons themselves, mostly belonging to low socio-economic strata.

Therefore, it is indispensable to incorporate the precautionary principle as an essential approach to identify other additional POPs, with the purpose of avoiding risks and further damages to the health of people directly or indirectly exposed to the chemicals; to preserve the genetic patrimony, human, animal and vegetable; to guarantee the right of the future generations to live in a healthy environment and to develop their full capacities throughout their lives.

Notes:

POPs represent a serious threat to health and to the environment because they may cause deseases such as cancer, congenital malformations, intellectual development problems, sterility, propensity to sickness. Their characteristics are:

- to remain for long periods in the environment.

- to accumulate in fatty tissues of most living organisms. To concentrate in the last links of the alimentary chain, reaching levels 70.000 times superior to those of the environment.

- to travel long distances all over the planet, including polar zones.

- to be poisonous to wild life and to humans,

Source: UNEP.

2. Some potential POP pesticides: 2,4-D, dicofol, endosulfan, pentachorophenol, lindane, pichloram, chlordecona, dichlobenil, 2,4,5-T, methoxichlor, 1,2-dichlorobenzene.

3. Instituto de Investigaciones Agropecuarias (INIA): DDT: Química descontrolada, Santiago, 1985.

- Dimitroff Djunovich, Natalia: Niveles de DDT y DDE en tejido y leche materna por cromatografía de gases. Santiago, Universidad de Chile, 1978. Research conducted among middle class population in central Chile. The study aims to obtain a first information on levels of contamination by organochlorine pesticides, DDT and its main metabolite DDe, in fatty tissues and in human milk by gas chromatography. It also takes into account the influence of these levels of pollution in living organisms, with its subsequent effects on health.

- Triviño, A. Iván: Contaminación de leche materna, tejido adiposo de mujeres y la leche de vaca, por acción de plaguicidas de alto nivel residual como DDT, BHC, Heptacloro, etc. The study indicates that DDT metabolites were found in a 100% of the samples.

- Silva, V.J.: Efecto de dos pesticidas organoclorados sobre el desarrollo embrionario y larval de Tetrapygus niger (Molina, 1782) Echinodermata, Arbacioida, Arbaciidae) y Loxechinus albus (Molina,1782) (Echinodermata, Echinoidea, Echinídae) " Memoria de título de biólogo Marino, Universidad de Concepción, Concepción, 1981.

- Pantoja, S., Pastene, L., Becerra, J., Silva, M. y Gallardo, A.:DDTs in Balaenopterids (Cetacea) from the Chilean coast. Marine Pollution Bulletin 15, 1984.

4. Ministerio de Agricultura.1983. Resolución N?4 Excenta (18/01/83) Diario Oficial República de Chile NI 31.469.

5. Detección de Pesticidas Organoclorados en Leche Materna, X Región, Chile. Proyecto Fondecyt 0067/89. Montes, L.; Tamayo,R.; Cristi, R.; Olivo, A.

6. INIA: Contaminación en el valle del Aconcagua, V Región. Informe Final. Instituto de Investigaciones Agropecuarias, Santiago. Proyecto Fia 72/80.

7. CONAMA: Perfil Ambiental de Chile. Capítulo 11: Estado de la Contaminación de los Suelos en Chile, 1994.

8. Op.cit.: Detección de Pesticidas organoclorados en leche materna, X Región, Chile.

9. Incidencia de Pesticidas Organoclorados en Leche Materna de Diferentes Estratos Socioeconómicos de la Región Metropolitana. Dita Marcus I. y Paz Robert, Revista Chilena de Nutrición. Volumen 19, No. 2, agosto 1991.

10. María Elena Rozas: El impacto del Nafta en el uso y comercialización de los plaguicidas en Chile. En, PLaguicidas en América Latina. Participación ciudadana en políticas para reducir el uso de plaguicidas. Editores: Luis Gomero y Erika Rosenthal, 1997.

11. Luis Montes y otros: Residuos de Pesticidas en las carnes de la Décima Región, Chile. Universidad Austral, 1986.

12. Hernán López V: Determinación de clorados en grasa de bovinos en la IX Región, Chile. Universidad de la Frontera, 1996.

13. "To eliminate (the insects) it is advisable to use one of these products: aldrin, in doses of 5'10 kg/ha; heptachlor, 10-15 kg/ha; furadan, 1,5-3,0 kg/ha." Cultivos forestales. Algunas recomendaciones. En, Revista Nuestra Tierra, N? 189. abril 1966. Fundación de Comunicaciones, Capacitación y Cultura del Agro del Ministero de Agricultura.

14. Sebastian Donoso y otros: Mujeres Temporeras del Agro. Realidad de la Región del Maule. Instituto de Investigación y Desarrollo de la Educación de la Universidad de Talca, 1996.

15. An inspection of chemical industries done in 1997 by the Servicio de Salud Metropolitano del Ambiente (SESMA) found that 34% of them presented breaches in industrial safety.

16. A fire in the Mathiesen-Molypac chemical industry on December 1997. Different chemicals were present, mainly PVC, wax and pesticides.

17. Prevalencia de Malformaciones Fetales Congénitas, Hospital Regional de Rancagua. Servicio de Ginecología y Obstetricia Hospital Regional de Rancagua, 1990. Dra. M.Victoria Mella.

18. The study was conducted by a health team headed by the chief of the Service of Gynecology and Obstetrics of the Hospital Regional de Rancagua, Dr. Jaime Hernández Kiger. It included the revision of all admittances to the ob-gyn services of the different hospitals of the VI Region.

19. Estudio preliminar y descriptivo sobre mujeres que abortaron en comunas de la Sexta Región. Santiago, marzo de 1994. Dra. Lucía Molina, Matrona, Carolina Videla.

20. Efectos genotóxicos de agroquímicos. Una aproximación epidemiológica. Dr. Víctor López del Pino, F. Godoy, Ximena Barraza. Epidemiología, Servicio de Salud O'Higgins, Salud Ocupacional y Unidad de Genética Hospital de Rancagua. Jornadas de Salud pública. Santiago, noviembre de 1996.

21. María Elena Rozas: Plaguicidas en Chile: La Guerra química y sus víctimas. Observatorio de Conflictos Ambientales, 1995.

22. Doctoras Pilar Soler y Mónica Hinrichsen, UCI Cardiovascular del Hospital Luis Calvo Mackenna.

23. Dra. Arlene Jacial, Bq. Carmen Oyanguren, Dr. Patricio Iglesias, Enf. Cecilia Benavente. Perfil Clínico-bioquímico en 32 trabajadores expuestos a Pentaclorofenol en dos industrias madereras de la Octava Región. Informe Final. Instituto de Salud Pública de Chile, Departamento de Salud Ocupacional y C. A. Santiago, Chile, 1987.

24. Patricia Alvarado, C. Benavente, C. Oyanguren, I. Rüdolff: Exposición Laboral al Pentaclorofenol. Instituto de Salud Pública de Chile. Servicio de Salud Concepción, Arauco, 1992.

25. Catastro de Conflictos Ambientales por Plaguicidas. Observatorio Latinoamericano de Conflictos Ambientales, 1998.

http://irptc.unep.ch/pops/POPs_Inc/proceedings/Iguazu/ROZAS.html