“80% of pesticides used in Costa Rica are considered ‘highly dangerous’”
Fernando Ramirez-Muñoz is a researcher and professor at the Regional Institute for Studies on Toxic Substances at the National University of Costa Rica. Ramirez-Muñoz is an agronomist, with a Ph.D in natural sciences for development and member of the Action Network on Pesticides and Their Alternatives for Latin America.
AgriBrasilis – Should pesticides in Costa Rica be banned?
Ramirez-Muñoz – In addition to the high use of pesticides in Costa Rica, certain pesticides already banned in other countries, due to their high danger to health and the environment, continue to be used.
According to the UN, a withdrawal of pesticides should be initiated, especially for those considered Highly Dangerous, as they cause serious and irreversible effects in the long term. There are pesticides that continue to cause many contamination problems in drinking water sources: this was the case of bromacil, for example, which is already banned for this reason, after many years of waiting for its removal. This is also the case with chlorothalonil, etoprophos, glyphosate, paraquat, etc.
AgriBrasilis – Do you consider the use of pesticides in the country alarming?
Ramirez-Muñoz – Yes, especially in some crops such as vegetables, bananas and pineapple. Consumption increases every decade, and the intensity of use accelerates, causing many problems for neighbors of crops that use these products. Biodiversity, a source of foreign exchange for the country, due to the attraction of tourists, is reduced and affected by the intensive use of pesticides.
In relation to herbicides, for example, Costa Rica has seven species of plants considered weeds that have developed resistances to different herbicides, in different crops. The other Central American countries have only one species of this type each, which indicates the high selection pressure for resistance due to the frequent use of herbicides.
AgriBrasilis – Why is there a lack of new molecules?
Ramirez-Muñoz – In Costa Rica there is a very robust registration system, which takes into account the health and environmental aspects, and not just the agricultural effectiveness that the products present for controlling pests. Therefore, many new molecules that present high persistence or toxicity characteristics are not registered, despite having cutting-edge technology. There is also a lack of personnel to carry out environmental risk assessments of these substances, as well as a lack of interest on the part of the chemical industry in registering pesticides for crops that do not generate high profits.
AgriBrasilis – Are the pesticides currently sold obsolete?
Ramirez-Muñoz – Not all of them. There is a wide range of active ingredients, some of which are very old, such as 2,4-D, organophosphates, and even organochlorines, and substances containing arsenic, with known carcinogenic properties. However, some latest-generation pesticides also present resistance problems.
AgriBrasilis – 80% of pesticides used in the country are considered “highly dangerous”. Why does this occur? What are the most used substances?
Ramirez-Muñoz – This information is correct: 80% of pesticides used in Costa Rica are considered “highly dangerous”. Some crops such as bananas, with large areas and very high use, use mancozeb, chlorothalonil, paraquat, glyphosate, and other products that are considered “highly dangerous”.
Mancozeb, for example, represents 40% of total pesticide use in Costa Rica. It is applied mainly by air to crops (50,000 ha) mainly of bananas and plantains.
Glyphosate is used without control in crops, urban areas, roadsides, canals, and roads. Paraquat is a special case, used mainly by small farmers (without any type of protection) and in pineapple farms, in frighteningly high doses: up to 20 liters/ha of 20% paraquat, which is equivalente to 4 kg/ha – an environmental sin.
AgriBrasilis – Could you comment on the use of glyphosate and its alternatives?
Ramirez-Muñoz – Glyphosate is the main herbicide used in the country, and the second most used pesticide in terms of quantity. It is used on all crops (to prepare the land before sowing) and on perennial crops several times (up to 8 times a year); also in urban areas, backyards, to dry sugar cane, on the banks of oil pipelines and railways, to clear vacant lots, etc.
There are many alternatives to glyphosate, for the most diverse situations. Replacing it with another herbicide is not the only option. Agroecology, for example, is seen as a key element for changing the production system. We cannot continue to produce food based on highly toxic and dangerous products, which contaminate important resources, such as soil, air, agricultural workers, animals, etc.