Isabel Mendez, a Costa Rican biologist and ecologist, achieved a milestone for the country in environmental conservation and public health. Thanks to her efforts and perseverance, Costa Rica banned chlorothalonil, an agrochemical widely used in agriculture.
Chlorothalonil has been primarily used as a fungicide, bactericide, and nematicide, and is effective on a range of vegetables and fruit crops. However, it has been banned by the European Union (EU) since 2019. The chemical was found to be a groundwater contaminant and a presumed human carcinogen.
Mendez emerged as a persistent voice in the fight to protect ecosystems and human health from this pesticide. Witnessing the crystal-clear waters turn into poison, affecting not only flora and fauna but also rural communities reliant on these water sources, Mendez chose to fight.
With data, studies, and admirable persistence, she challenged the industry that profited from chlorothalonil. However, the toughest fight was against the apathy of authorities and the indifference of a significant part of society. She was largely ignored, as chlorothalonil was seen as essential for agricultural productivity.
Mendez continued to present evidence showing how this chemical was damaging the environment and endangering human health. She mobilized different groups, academia, and media, eventually forcing the government to act.
In August 2024, Costa Rica banned chlorothalonil, becoming one of the few countries to take such a strong stance against this chemical.
While many celebrated this decision, the agricultural sector feared it would harm productivity. However, Mendez, along with experts and researchers, is working to show that sustainable alternatives do not threaten humans or the environment.
The agricultural sector’s warning should prompt state action, which has long neglected producers. The fight against this pesticide is one of many environmental battles in the country. Although Costa Rica boasts of being “green,” its actions often fall short. This milestone rekindles hope for a Costa Rica that truly protects the environment and upholds the constitutional mandate of a healthy, balanced environment.
