Organochlorine forbidden in Europe causes high death toll among cattle in Paysandu

A new incident involving endosulfan as protagonist occurred a few days ago in the City of Guichon, 110 Kilometres to the east of the capital of the region of Paysandu. On 9th April, a spray plane suffered a fault in flight and dropped an unknown quantity of endosulfan on a field where cattle were pastured.

According to first estimates, just one day after the incident, 50 young animals of more than 250 kg in weight died from eating contaminated grass. In addition hundreds of fish, reptiles and birds of many species. As if this were not enough, fish mortality has been detected in a river (Cañada del Horno) that provides water to the drinking water plant and to the city itself [1].

Obviously this is an unfortunate accident and normally nobody drops endosulfan on a field where animals are feeding. It was the presence of the cattle, their poisoning and subsequent death, that made this incident “news”. As a neighbour said to the press, “we only realise there’s a problem when the animal is dying.”

All the same it is essential to bear in mind that even when there are no cows or people suffering the direct impacts of the poison, endosulfan is no less dangerous and that it is an insecticide that is frequently used to combat shield or stink bugs in soya production.

What is endosulfan?

Endosulfan is an organochlorine insecticide. It is classified by the Environmental Protection Agency of the US and the European Union as category 1b, highly dangerous. In scientific literature there is plenty of information about its high level of (eco) toxicity, what happens to it in the environment, its residues in food and forage and its concentration levels in the environment. Based on available information, endosulfan may be classified as a Persistent Organic Pollutant (POP). It brings together the four characteristics that cause a substance to be classified as a POP: high toxicity to nearly all living organisms, very persistent in the environment, high bio-accumulation levels, and it travels long distances.

In laboratory animals, encosulfan is neurotoxic, nephrotoxic (kidney poison) [2] It causes congenital physical impacts, mental impacts and death among workers and rural populations. Endosulfan is found to be involved in the majority of cases of poisoning by pesticides notified at global level [3]. Endosulfan is highly persistent. It has been found to remain for than a year in the soil [4]. It has a heightened level of bio-accumulation. Studies with freshwater and slat water fish show high levels of bioaccumulation, from 2,400 to 11,000 [5]. It can be carried great distances through the environment. There is abundant information available corroborating the presence of endosulfan massive distances from where it is produced or used, such as the air and waters of the Arctic [6].

It is prohibited throughout the European Union

Because of all the above, the EU has prohibited the commercialisation and use of endosulfan and has asked for it to be included in the list of the Stockholm Convention, a process designed to limit and prohibit the use of Persistent Organic Pollutants.

Even though all available scientific investigations have indicated for a long time that Endosulfan should be prohibited worldwide and is in many countries, in ours it continues to be used at increasingly high levels.

Endosulfan in Uruguay

The principal application for endosulfan in our country is soy cultivation. From the beginning of the soya “boom” we saw an explosive increase in imports of endosulfan. During 2007, for example, 250 tonnes of endosulfan were imported, some 50 times the amount imported 7 years before. Logically enough, this massive use of endosulfan soon began to show its consequences. Its presence has been confirmed in soils in our country [7] and in the hydroelectric dam’s reservoir at Salto Grande [8]. Residues of organochlorines (among which is endosulfan) have been detected in fish from the Uruguay River. [9]. In addition, there have been a number of cases of serious poisoning of animals and human beings due to endosulfan [10]. To these we must add the event at Guichon, whose full significance has still to be assessed.

Massive impacts

Endosulfan has been prohibited for many years in Europe, precisely because there is no way to guarantee its safe use, in spite of the high levels of regulation and control in Europe. In Uruguay its use continues to be permitted. What happened in Guichon is a disaster, but it has allowed us to fully appreciate the impacts of this insecticide. Unfortunately the destruction caused by this substance appears to have been overlooked for years. We hope that now, following the events at Guichon, the authorities forbid the use of this substance and that Uruguay will join the large number of countries that consider this insecticide a silent assassin that must therefore be prohibited.

RAPAL Uruguay
13 April 2009
Translated by Helena Paul


[1] Diario La República, 12 de Abril de 2009
[2] ATSDR (Agency for Toxic Substances and Disease Register). Toxicological Profile for Endosulfan, septiembre de 2000. Se puede consultar en la dirección siguiente:
[3] End of the Road for Endosulfan. Environmental Justice Foundation (2002).
[4] Laabs, V. y otros. Fate of 14C-labelled soybean and corn pesticides in tropical soils of Brazil under laboratory conditions. J. Agric. Food Cehm. 50, págs. 4.619 a 4.627 (2002).
[5] Schimmel, S.C y otros. Acute toxicity and bioconcentration of endosulfan in estuarine animals. En: Aquatic Toxicology and Hazard Evaluation, editado por F.L. Mayer, J.L. Hamelink, 1st Symp. ASTM STP 634, Philadelphia (PA), págs. 241 a 252, (1977).
[6] - Ruedel, H. Volatilization of pesticides from soil and plant surfaces. Chemosphere 35 /1/2) págs. 143 a 152, (1997).
[7] Instituto Nacional de Investigación Agropecuaria, 2005
[8] CARU. 1993. II Seminario de calidad de aguas y control de la contaminación en el Río Uruguay. Colón, Argentina.
[9] Bruno, A. Plaguicidas usados en el cultivo de soja. Evolución de su uso y estimación de su impacto ambiental, Río Negro, 7 junio de 2007 en seminario organizado por CAF (2007).
[10] Efectos del endosulfán en el Uruguay: casos de intoxicación registrados. RAP-AL Uruguay, 2006 -