Pesticides have been dropped from planes and even helicopters with the aim of evading IBAMA, the Brazilian environmental agency, for years as a method to clear remote and hard-to-reach areas of the Amazon rainforest. That practice — used more frequently since 2018 — takes longer than clear-cut deforestation (the removal of all existing vegetation using heavy machinery). On the other hand, pesticide use cannot be detected via real-time satellite imagery.

According to IBAMA, some pesticides work as defoliants. The dispersion of those chemicals over native forest is the initial stage of deforestation, causing the death of leaves — and a good part of the trees. The material is burned and surviving trees are  removed with chainsaws and tractors.

“Although human-induced forest degradation takes a few years to happen, the process is advantageous to criminals because chances of being caught are very low. We can only see the damage when the clearing is already formed,” notes an IBAMA official who spoke with Mongabay on the condition of anonymity. “A dead forest is easier to remove than a living one. Certain (not all of them) pesticides practically leave only big trees standing.”

In the next step, the offenders drop grass seeds by aircraft. “This is the great bargaining chip for land grabbing. In order for illegal land to be sold as a ‘farm in formation,’ the soil must be covered with grass,” added the agent.

Glyphosate, carbosulfan (prohibited on aerial spraying) and 2,4-D (a component of Agent Orange, used massively in the Vietnam War and which still results in cases of birth defects in the country) were some of the pesticides found by the environmental agency in clearings in the Arc of Deforestation (the Legal Amazon area where the agricultural frontier advances towards the forest), according to a survey by Repórter Brasil and Agência Pública.

“Causing forest degradation through pesticides is a major aggression to the environment. The 2,4D herbicide, for instance, is capable of killing large trees, and the carbosulfan insecticide is highly toxic. Animals will eat poisoned leaves and fruits from the forest [while the vegetation dies]. And it’s very dangerous for anyone nearby when pesticides are thrown,” said Eduardo Malta, a biologist at the NGO Instituto Socioambiental (ISA), in an interview.

In an IBAMA video sent to Mongabay, two inspectors show a rural property on which they detected, during an overflight, an area of about two hectares (4.9 acres) with dry, brownish vegetation. Upon landing at the site, they found dozens of empty gallons of the Planador XT herbicide — which had been dumped into the area by helicopter at the owner’s behest.

“Although that product is authorized to be applied by agricultural aircraft, its use is prohibited in native forests,” states one of the IBAMA agents in the video. “In addition, the containers thrown on the soil were not washed or disposed of properly, and the rains could end up transporting the residues. Adults, children [of farm workers] and animals live on the site. Everyone has their health put at risk.”

Cattle farms buying pesticides — what for?

As the IBAMA video shows, not only do land grabbers release pesticides to deforest, but farmers also do so on their own properties. Faced with the increased number of cases, IBAMA began to map those areas through INPE’s (Brazilian space agency) forest degradation alert system. When cross-referencing the data, the environmental agency found that many of the clearings were located on farms that were purchasing pesticides, mainly in the state of Mato Grosso.

Such properties, however, were livestock farms and not agricultural ones, so it did not make sense to purchase those products.

“The criminals noticed that forest degradation was not our priority because we only arrived at those places much later, when the clearings were already formed. So they began practicing more of those,” the IBAMA representative told Mongabay. “The truth is we were more focused on fighting clear-cut deforestation due to the increasing rates in recent years. It was a learning experience for us.”

The reduced number of field agents to cover all six Brazilian biomes, and not just in the deforestation area, is a big problem. In 2019 they were only 591, which is 55% less than compared to 2010 (when it was 1,311).

2010 was the last year that IBAMA opened new vacancies for enforcement agents.

“It is unfortunate the irresponsibility of those people towards human life and the environment. Pesticides were not made for that purpose, there are no scientific studies on the consequences of dumping those products in the native forest, and the effects on living beings, water and soil,” said the agent. “In addition to IBAMA, Embrapa a public agricultural research company linked to the Ministry of Agriculture and the Ministry of the Environment, among others, must participate in the effort of raising awareness and educating rural producers and the population. The agency alone in this battle is an inglorious fight.”