“The impact is severe, persistent and widespread, affecting the soil and, above all, water resources…”
Marco Antonio Delfino is a federal prosecutor at Brazil’s Federal Prosecutor’s Office (MPF), a specialist in constitutional law, with a degree in legal sciences from the Campo Grande University Center and a master’s degree in anthropology from the Federal University of Grande Dourados.
AgriBrasilis – What is the environmental impact of using the herbicide atrazine in the Dourados River Basin?
Marco Antonio Delfino – The impact is severe, persistent and widespread, affecting the soil and, above all, water resources. Atrazine has high environmental persistence and significant mobility in soil, being carried by rainwater runoff into rivers, streams and groundwater. The damage is a direct and expected consequence of the product’s massive dissemination. International regulatory experience, such as that of the European Union, has recognized that it is impossible to prevent groundwater contamination at safe levels due to the agricultural use of this product.
AgriBrasilis – Is the presence of atrazine and its metabolites occasional, or does it indicate chronic contamination?
Marco Antonio Delfino – The presence of atrazine and its degradation products (metabolites) indicates chronic and widespread contamination. Scientific reports from Embrapa attest that, in 2021, atrazine was detected in 100% of the 117 samples collected from the Dourados River. Its metabolites, deethylatrazine (DEA) and 2-hydroxyatrazine, were also found at high frequencies (90% and 97%, respectively), confirming that the pollutant has become a permanent component of the ecosystem.
AgriBrasilis – The Federal Prosecutor’s Office (MPF) has filed a Public Civil Action regarding atrazine contamination in the Dourados River Basin. What requests were made to the courts?
Marco Antonio Delfino – The MPF seeks joint liability of the manufacturing/marketing companies and Ibama. The main requests are:
- Emergency Injunction: requiring the companies to present, within 60 days, a work plan for a complete assessment of soil and water contamination in the Dourados River Basin (BHRD) and ordering the companies to refrain from marketing products containing atrazine. It also requests that Ibama immediately implement residue monitoring.
- Merits (Final Ruling): joint condemnation of the companies under an Obligation to Act (to fully fund and implement a Degraded Area Recovery Plan — PRAD) and an Obligation to Pay (collective moral damages and environmental damages) in the amount of US$ 54.7 million. The MPF also requests that Ibama initiate the procedure for re-evaluating atrazine’s registration.
AgriBrasilis – How did the Federal Prosecutor’s Office (MPF) determine the defendants in this case and why was Ibama included?
Marco Antonio Delfino – The defendants are private companies (manufacturers, importers and marketers, including companies such as Ouro Fino Química and Nortox) and Ibama (the Brazilian Institute of the Environment and Renewable Natural Resources).
The private companies are defendants because they are the primary generators of the risk and of the environmental damage, and are therefore objectively and jointly liable for placing a dangerous product on the market.
Ibama is a defendant due to its omission. The Institute has the legal power and duty to control substances that pose risks and to carry out environmental monitoring of pesticides since 1996. Its failure to present a detailed assessment of water exposure to atrazine and to initiate the re-evaluation of the product’s registration—despite robust information regarding the risks—justifies its inclusion as a defendant in the case.
AgriBrasilis – With this lawsuit, what is expected regarding the use of atrazine in Brazil?
Marco Antonio Delfino – The expectation is to curb the use of atrazine [36, 400c] and to correct the structural pattern of disproportionate exposure of vulnerable groups to chemical contamination. The lawsuit seeks to compel Ibama to fulfill its duty of oversight and monitoring and to initiate the procedure for re-evaluating atrazine’s registration. Atrazine is already banned in 44 countries, including the entire European Union since 2003 and Switzerland since 2012, which reinforces the need for restriction or prohibition in Brazil.
AgriBrasilis – Can this case serve as a precedent for other similar actions?
Marco Antonio Delfino – Yes. The MPF argues that contamination in the Dourados River Basin is a “faithful portrait of what happens in numerous other river basins” in agricultural regions. The Public Civil Action establishes precedents by grounding corporate and state responsibility for human rights violations, invoking Advisory Opinion No. 32/2025 of the Inter-American Court of Human Rights (OC-32/25) and the Belém Declaration (2025) on environmental racism. OC-32/25 requires enhanced due diligence and corporate transparency regarding environmental risks, applying to harms such as large-scale chemical contamination.
AgriBrasilis — Besides atrazine, are other pesticides a cause for concern in the Basin?
Marco Antonio Delfino – Yes. Studies conducted in Guarani Kaiowá communities (Jaguapiru Village and the Guyraroká Reclaiming Area) found surface water, drinking water and rainwater contaminated by 22 active ingredients (AIs) of pesticides. In the Guyraroká Indigenous Land, residues of 11 pesticides were detected in drinking water, including atrazine and 2,4-D.
AgriBrasilis – What are the main impacts identified for the Guarani Kaiowá communities?
Marco Antonio Delfino – The impacts characterize a pattern of environmental racism, as the harm disproportionately affects these populations. Exposure to atrazine violates the rights to health and to food sovereignty.
- Health and Toxicity: atrazine is classified as an endocrine disruptor and proven to be carcinogenic in laboratory tests, associated with hormonal disorders, reproductive abnormalities and increased risk of neurodegenerative diseases such as Parkinson’s.
- Indigenous Contamination: Embrapa reports confirmed the presence of atrazine and its metabolites in multiple water sources in the villages (tap water, shallow wells and streams). Atrazine was also detected in rainwater in Jaguapiru Village.
- Vulnerability: the harm is worsened by the vulnerability of these communities, whose health and way of life depend on the contaminated resources.
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