Study links Brazil’s most widely used pesticide to increased infant deaths

RIO DE JANEIRO, BRAZIL – Glyphosate used in soy farming contaminates rivers and affects births, claim researchers from Princeton, FGV, and Insper.

Glyphosate is the most widely used pesticide in Brazil. It represents 62% of all herbicides used in the country and, in 2016, sales of this chemical in thousands of tons was higher than the sum of the 7 other highest selling pesticides in the national territory.

Associated with the production of genetically modified (GM) soybeans, the herbicide contributed to Brazil becoming the world’s largest producer of grain, surpassing the United States.

As a result, GDP (Gross Domestic Product) in producing states has grown much faster than the country’s economy as a whole in the last decades. And the income generated by this agricultural activity has boosted other economic sectors in producing regions.

But a study conducted by researchers from Princeton University, FGV (Getulio Vargas Foundation) and Insper (school of business, economics, and engineering) reveals that this wealth generation comes at a high cost: according to the survey, the spread of glyphosate in soybean plantations led to a 5% increase in infant mortality in municipalities in the South and Midwest that are supplied water from soy-growing regions.

“There is great concern about the effects of herbicides on populations not directly involved with agriculture, who are not directly exposed to pesticides,” observes Rodrigo Soares, professor of the Lemann Foundation Chair at Insper and one of the study’s authors, along with Mateus Dias (Princeton) and Rudi Rocha (FGV).

“Although these substances are present in the bodies of over 50% of the Western population, we do not know if this is harmful or not,” adds the researcher.

Bayer, owner of Monsanto since 2018 – the company that launched glyphosate on the market in 1974, under the trade name Roundup – considers the study’s findings “unreliable and poorly conducted” and says that the safety of its products is the company’s highest priority.

For its part, APROSOJA (Brazilian Association of Soy Producers) states that “the study’s findings do not seem to be supported by scientific facts and the reality observed in the practice of Brazilian agriculture.”

Finally, CropLife Brazil, one of the bodies representing the pesticide industry in the country, pointed out in a statement that “for over 40 years, glyphosate has undergone extensive safety testing, including 15 studies to assess potential human developmental toxicity and 10 studies to assess potential reproductive toxicity.”

“Regulatory authorities in Brazil, Europe, the U.S. and around the world have reviewed these studies and found that glyphosate poses no risk to human development or human reproduction,” the organization says.

Glyphosate use in Brazil

The most widely used herbicide in the world today, glyphosate was developed by Monsanto in 1970. The pesticide is used to eradicate weeds in agriculture, and acts by blocking an enzyme that is part of the synthesis of amino acids essential for plant development.

Glyphosate is a non-selective herbicide, i.e. it kills most plants. For this reason, its use in agriculture became popular in association with genetically modified crops to resist the active ingredient.

This is the case of transgenic soy, marketed by Monsanto under the name Roundup Ready, precisely because it is resistant to glyphosate, sold by the company under the name Roundup. However, the glyphosate patent has been expired since 2000, and the product is now offered by several manufacturers under different trade names.

Genetically modified soybeans were first marketed by Monsanto in the United States in 1996.

In Brazil, a first authorization for use was granted in 1998, but was almost immediately suspended by the courts. In 2003, the government granted a temporary marketing authorization, but determined that residual seeds would be incinerated to prevent their reuse the following year.

In September that year, a provisional measure allowed producers to reuse the seeds and, in October 2004, the temporary sale authorization was renewed. Finally, in March 2005, the Biosafety Law permanently authorized the production and sale of transgenic soybeans.

The use of genetically modified soy spread rapidly throughout Brazil from 2004 on, representing 93% of the area planted with the grain in the mid-2010s, according to data from the United States Department of Agriculture (USDA), cited by the Princeton, FGV and Insper researchers.

Along with the soy crop productivity gain, the use of glyphosate has grown strongly in the country, more than tripling in volume between 2000 and 2010, from 39,500 to 127,600 tons.

Differences between Brazil and other countries

The European Union has been widely debating the possibility of banning the use of glyphosate since 2015, after a report by the International Agency for Research on Cancer (IARC) that year classified the substance as a “probable human carcinogen,” that is, as a potential cancer-causing agent.

In the United States, Bayer has settled billions of dollars in lawsuits over accusations that glyphosate causes cancer.

In Europe, authorization to use glyphosate is currently valid until December 2022. Austria became the first country in the region to ban the product, in 2019, while Germany plans to do without the herbicide from 2024.

Another important difference concerns the maximum permitted concentration value of the pesticide in water for it to be considered suitable for human consumption.

“Brazilian water can be considered drinkable containing up to 500 micrograms of glyphosate per liter, while water in the European Union can have a maximum of 0.1 microgram of glyphosate,” Tygel highlights. “So the Brazilian limit is 5,000 times higher than the European Union limit.”

As if these already existing regulatory differences were not enough, in recent years Brazilian agribusiness has been pressing for the approval in Congress of Bill 6,299/2002, which relaxes the rules for inspection and application of pesticides. The bill has been nicknamed “PL do Veneno” (Poison Bill) by environmentalists.

In addition, within the federal government there has been a change in the correlation between the forces opposing and favoring the use of pesticides.

“Until 2016, within the government there was a certain balance of forces between agribusiness, family farming, and public policies to encourage agro-ecology,” assesses the member of the anti-pesticide campaign.

In 2020 alone, Brazil approved the registration of 493 pesticides, the highest number ever documented by the Ministry of Agriculture, which has been compiling these data since 2000.

Glyphosate and infant mortality

The authors of the study “Down the River: Glyphosate Use in Agriculture and Birth Outcomes of Surrounding Populations” say they decided to study the relationship between the pesticide and infant mortality because of the heated debate regarding the use of genetically modified seeds and their combination with herbicides.

“We felt the debate was too passionate and too uninformed,” says Insper’s Rodrigo Soares. “Then we realized that the expansion of transgenic soy in Brazil, especially in the Midwest and South, as it was very rapid and very marked after the introduction of modified seeds, could be an interesting context for analysis.”

The regulatory change that allowed the use of genetically modified soy seeds in Brazil generated what is called in economics a “natural experiment” – an event brought about by external causes, which changes the environment in which individuals, households, companies or cities operate, and which makes it possible to compare groups affected and unaffected by that event.

“To assess this, we used information about watersheds in the country and the relative position of municipalities – above or below areas of intensive glyphosate use,” explains the researcher.

“It was a way to understand how the increase of genetically modified soy and glyphosate use in a particular municipality could affect the municipalities receiving water that passes through that particular region where the pesticide is used.”

What the researchers then did was analyze, for the period between 2004 and 2010, when the largest expansion of GM soybean production in Brazil occurred and glyphosate use tripled, the birth statistics of these municipalities “downstream” from areas of intensive herbicide use.

Within this deterioration in health conditions at birth are: increased likelihood of low birth weight, increased likelihood of premature births, and – most seriously – increased infant mortality.

“We also produced a number of other empirical analyses to show that this was indeed associated with water and that this indeed appears to be associated with soybean expansion.”

Isolating the effect of glyphosate

For example, by comparing data from “downstream” with “upstream” municipalities – which therefore are not supplied the water that has passed through areas of glyphosate use – the researchers find that “upstream” municipalities are not affected by this worsening of birth statistics.

The researchers also show that the negative effects on birth health outcomes are particularly strong for pregnancies most exposed to the glyphosate application period, which in Brazil typically occurs between October and March, since soy is planted in the country between October and January.

The worsening of birth data is also greater when it rains more during the glyphosate application season, the researchers show by cross-referencing health statistics with rainfall data, which confirms the theory that a greater amount of the product reaches rivers when soil erosion by rain is more significant.

Mateus Dias, a doctoral student at Princeton University and Soares’ co-author on the study, explains the choice of analyzing downstream and upstream municipalities, rather than the municipalities that apply glyphosate.

The researchers also evaluated whether soybean expansion affected soil erodibility due to the advance of agriculture over forested areas.

“We showed that this did not happen, because these areas that started planting soybeans seem to have been pastures before, so there was no radical change in vegetation and, consequently, no significant change in soil erodibility,” reports Dias.

Agribusiness sector contests the results

BBC News Brazil forwarded the study conducted by Dias, Rocha and Soares to Bayer, APROSOJA and CropLife Brasil, so that the herbicide manufacturer, the soybean sector association and the body representing the pesticide industry could comment on the results.

“The authors’ conclusions are inconsistent with the expressive consensus among leading health authorities around the world, including ANVISA, Brazil’s health regulator, that glyphosate does not cause harm to human development or reproduction,” said the current owner of Monsanto.

“That is, the references that establish the causal link pointed out by the researchers were not obtained in Brazil, because Brazilian tropical soils have a high variable load, have high levels of aluminum and iron and, with the planting techniques such as no-till farming, seed microbiolization, among others, Brazilian soils are rich in an active biomass, that is, a high microbial activity,” argues the agricultural association.

APROSOJA also criticizes the correlation made by the researchers between what it calls “potential damages” with glyphosate-resistant soybeans.

“Again, the authors have forgotten or are just not sure what they want to answer because, besides soy, several crops use glyphosate to control weeds,” argues the entity.

CropLife Brazil points out that the pesticides used in the country go through approval by three different bodies – ANVISA, IBAMA (Brazilian Institute of Environment and Renewable Natural Resources) and the Ministry of Agriculture; that the three bodies analyze environmental impact, toxicological and residue studies that follow international quality methodologies; and that in each of these registrations it is necessary to present tests and studies conducted in laboratories certified in good practices, which must be conducted in accordance with the protocols of the OECD (Organization for Economic Cooperation and Development).

Study results may contribute to improved regulation

According to the researchers, the goal of the study is not to “demonize” glyphosate, but rather to contribute to an improvement in public policies regulating the use of pesticides in the country.

“We know what the use of agricultural substances in general – fertilizers, herbicides, pesticides – has meant throughout human history. They actually enabled a revolution in terms of agricultural production and, in the overall result, I believe the effect was very positive,” says Soares, from Insper.

“We have the production we have today, with its impact on food prices and on the populations involved with agriculture that benefit from the productivity gains, because of these substances,” he adds.

“That doesn’t mean we shouldn’t be aware of the potential negative effects,” he says, advocating changes in regulations for the use and management of pesticides and the protection of waterways and groundwater.

Alan Tygel, from the Permanent Campaign Against Pesticides and for Life – created in 2011 and comprising more than a hundred social movements, trade unions and class entities, NGOs, cooperatives, universities and research institutions -, has a more radical opinion on the issue.

“We consider that the central goal is in fact to end the use of these substances, especially because today there is no doubt about the technical capacity to produce food without the use of chemical and synthetic pesticides,” argues the activist.

According to him, the campaign’s proposals are contained in a bill (PL 6670/2016), which establishes a National Pesticide Reduction Policy, with measures that include everything from a ban on aerial spraying, to state support for agro-ecology, to a ban on pesticides banned in their countries of origin and an end to tax exemptions for pesticides.

“We’re going to fight for every small gain we may get, because we know that every percentage less of pesticides used is saving lives,” says Tygel.

“But we know that there is no possible coexistence between organic production and the massive use of agrotoxics. The path we envision is one of a production model that can be adopted nationally totally free of pesticides and transgenics.”

Source: G1