Earlier this year, the World Health Organization (WHO) published a report on the effects of glyphosate, the active ingredient in Roundup; a popular herbicide produced by biotech giant Monsanto. The report concluded that the chemical – even at small doses – is “probably carcinogenic to humans.”

The Evidence Builds

The WHO report isn’t the first time Monsanto’s product has been put under scrutiny for its effects on people’s health and the environment. A 2013 report by the scientific journal Entropy linked the herbicide not only to cancer, but other devastating illnesses like Parkinson’s disease. In addition, glyphosate is now widely considered to be in the family of endocrine-disrupting chemicals – chemicals that, at certain doses, can interfere with the endocrine (or hormone) system in mammals – that cause birth defects.

This mounting evidence hasn’t stopped the agrochemical giant from selling Roundup, or the seeds that are genetically engineered to withstand the herbicide. Using these seeds, farmers are able to easily control weeds using Roundup without damaging their crops. Monsanto’s success at marketing these seeds has meant that over 80 percent of crops worldwide are genetically engineered to be grown with the herbicide.

For decades, concerned citizens have been in an uproar as more reports confirming the chemical’s effects are published. Movements such as March against Monsanto are gaining momentum and ordinary citizens are starting to file a series of lawsuits against the company.

A Brave Mother Steps In

2012 Goldman Prize winner Sofia Gatica is no stranger to the chemical’s human cost – just three days after her birth to a daughter, Sofia’s infant died of kidney failure, likely caused by pesticide exposure.

Gatica lives in Ituzaingó, a working-class neighborhood in Argentina that’s surrounded by genetically modified soy fields. Her home country is the third-largest exporter of soy products in the world, and farmers there use 5 million gallons of Roundup each year. Until 2012, the fields near her home were sprayed on a daily basis with Roundup:

“For me, these soybeans mean only destruction and death.”

Following the death of her child, Gatica began going door to door, talking to her neighbors about illnesses in their families. She mapped out her findings, and was astonished at what she saw: the cancer rate in her community was 41 times the national average. This led to a subsequent investigation by the federal government, which confirmed that low concentrations of glyphosate were causing birth defects. The findings meant that the chemical cannot legally be sprayed within 2,500 meters from homes. In addition, a 2010 ruling from the Supreme Court has not only banned agrochemical spraying near populated areas, but it also reversed the burden of proof: Residents no longer need to prove that spraying causes harm but instead, the government and soy producers must now prove the chemicals are safe.

The Reality of Fighting Big Ag

For a mother with no organizing experience and a high-school education, fighting huge corporations like Monsanto was never going to be easy. Along with the organization she co-founded—Mothers of Ituzaingó—she endured insults and threats from individuals, police officers, and local business owners. In 2013, she was physically attacked by an intruder in her home:

“A man put a gun to my head and told me stop messing with the soy. But I wasn’t going to let them stop me.”

True to her word, Gatica continued to expose the truth behind glyphosate’s toxicity to humans: She partnered with Dr. Andres Carrasco, director of the laboratory of molecular embryology at the University of Buenos Aires to conduct a study into the effects of glyphosate on frog and chicken embryos and concluded that the toxicity of the chemical should not be underestimated:

“I suspect the toxicity classification of glyphosate is too low,” wrote Carrasco. “In some cases this can be a powerful poison.”

Seeds of Hope

As questions around glyphosate’s safety continue to rise, Monsanto remains adamant in its position that the chemical is not toxic to humans. With mounting public support and even with the endorsement of celebrities like singer Neil Young, movements like Gatica’s continues to gain strength. The company’s revenues are taking a dive and the American Academy of Pediatrics has officially cut ties with Monsanto – thanks to the mothers like Gatica speaking out to protect their children.

As for Gatica, she continues to work with fellow mothers and activists to resist Monsanto’s advances. She recently organized a blockade that successfully stopped them from building a plant in the Falkland Islands. The plant would have been the largest producer of genetically modified corn seed in South America – a seed developed to be grown with Roundup.

Together with Mothers of Ituzaingó, Gatica is working with mothers of other Argentine communities, looking for ways to expand protections to families across the country.

“Seeds are the heritage of humanity. Those who control our seeds control our food and our future.” – Sofia Gatica

Follow Gatica on Twitter for ways to get involved (in Spanish) or check out Pesticide Action Network’s online action center for ways to promote healthier alternatives to pesticides.