- A study has found that women exposed to pesticides during farm work in Brazil’s Paraná state have a 60% higher risk of developing breast cancer, and a 220% higher risk of metastasis.
- While they don’t typically spray the pesticides, these women are responsible for cleaning the equipment and clothing used to do it, during which they rarely wear personal protective equipment.
- The study found glyphosate, atrazine and 2,4-D in urine samples from rural women; health and regulatory agencies consider these three pesticides as possibly or probably carcinogenic.
- Brazil has one of the most permissive pesticide markets in the world, where levels of exposure to chemicals like glyphosate are several times higher than in more strictly regulated jurisdictions such as the European Union.
Women farmers living in Brazil’s Paraná state run a 60% chance of developing breast cancer and a 220% increase in the risk of metastasis, according to a new study. Breast cancer risk in the region, which is dominated by family farms with intensive use of pesticides, is 41% higher than the average for Brazil; the mortality rate from the disease is 14% higher.
The recent study, published in the journal Environmental Science & Technology, is the first of its kind conducted with women in the country; it included 758 subjects, split between those who had been exposed to pesticides and those who hadn’t.
“The research shows the direct link between exposure to pesticides and high incidence of breast cancer in the farmers,” said study lead author Carolina Panis, from the tumor biology lab at Western Paraná State University. “Although they do not spray the pesticides, those women are responsible for decontaminating the protective equipment and washing the clothes used to do it. Doing that without gloves is enough to cause contamination.”
Brazil, a global agricultural powerhouse, also has one of the most permissive pesticide regimes of any country. There are 42 active pesticide ingredients considered probably carcinogenic that are licensed for sale in the country; 27 of these are classified as possibly carcinogenic by the U.S. Environmental Protection Agency and the World Health Organization’s International Agency for Research on Cancer (IARC).
In Paraná, a state in southern Brazil, glyphosate stands out among the top 10 most used pesticides from 2013 to 2020. It accounts for almost 50% of all pesticide trade, according to state agriculture regulator ADAPAR. For her study, Panis analyzed urine samples from women farmers, finding that many tested positive for pesticides such as glyphosate, atrazine and 2,4-D.
The IARC classifies glyphosate as probably carcinogenic to humans, in addition to being an endocrine disruptor; 2,4-D is seen as possibly carcinogenic and there’s evidence that it increases the incidence of reticular cell sarcoma in female mice; atrazine, the No. 5 most common active pesticide ingredient traded in Paraná in 2020, can also induce endocrine disruption.
In Brazil, the permissible limit for atrazine levels in the human body is five times higher than that approved in the European Union. For glyphosate, it’s 200 times higher.
“These women’s urine tests revealed contamination by glyphosate, atrazine and/or 2,4-D, resulting from unprotected exposure while washing and decontaminating items used to spray pesticides on crops,” Panis said. “In addition, the risk of developing breast cancer was almost 60% higher among rural women (exposed) compared to urban women (not exposed).”
Invisible and silent impacts
Maria Elizete Chaud, 51, lives with her husband on a rural property, 6 kilometers (about 4 miles) from the town of Planalto in southwestern Paraná. She grew up in the countryside, surrounded by tobacco plantations, which are known for their intensive use of pesticides.
“I’ve lived in the countryside since I was a child, and we always planted tobacco and used a lot of poison,” she said. “I never sprayed it, but I was always in the middle of it. I guess we end up getting used to it.”
A 2017 study found that tobacco farming uses an average of 60 liters of pesticide per hectare, or about 6 gallons per acre — the highest of 21 crops assessed. The study was conducted by researchers from the Center for Environmental Studies and Workers’ Health at Brazil’s Federal University of Mato Grosso (UFMT), a leading institution in the field.
Chaud was diagnosed with breast cancer in 2016. She underwent chemotherapy, radiotherapy and three surgeries. She is cured now, but must remain under observation until 2026. “I’d never had any health problems before; it was a shock at the time because it is a complicated disease. I don’t know where it came from, I don’t know if it was the poison,” she said.
Although women working on farms aren’t typically the ones spraying pesticides, they’re involved in secondary activities that expose them to contamination. They’re often the ones who prepare the mixture of chemical products, accompany their husbands during spraying, and in particular are responsible for cleaning up the tools used in the fields. This domestic work can also lead to contamination as high as that faced by men who actually spray the pesticides.
“Our study shows that at least 90% of women who wash garments worn during spraying and decontaminate personal protective equipment do not wear protective gloves, and that becomes the main route for pesticides to enter these people’s bodies,” Panis said.
Chaud said she frequently handled contaminated garments. “I never even considered wearing gloves. Poison is always used in everything to be planted and harvested. The need to wear gloves should be communicated when these products are sold, but that information is not provided.”
Her husband currently works in corn and soybean farming. He still sprays pesticides, but now he decontaminates his own clothes and PPE. Male farmers, like women, are also routinely exposed to multiple pesticides with carcinogenic, reproductive, neurotoxic, endocrine-disrupting, and respiratory effects, among others. Several studies in Brazil have looked at these effects on men’s health. One, from the municipality of Farroupilha in the southernmost state of Rio Grande do Sul, found that endocrine-disrupting pesticides can cause testicular and prostate cancer in addition to reproductive disorders in men who are chronically exposed to them. The research was the doctoral thesis of Cleber Cremonese at the Oswaldo Cruz Foundation, one of the world’s leading public health research institutes.
“When they spray the poison in nearby fields, I can smell it,” Chaud said. “I close the whole house, but I smell it anyway. Everyone around me sprays poison, and on windy days the smell travels far.”
“The results of the research indicate that women who are continuously exposed to pesticides face a higher risk of developing more aggressive breast cancer, which stresses the urgency of having public policies focused on prevention and monitoring for these populations”, Panis said.
Clarice Wals, 47, lives in São Jorge do Oeste, also in southwestern Paraná. She had to change jobs after being diagnosed with breast cancer in 2016. “It only dawned on me when I took a shower and saw myself in the mirror after surgery,” she said.
Wals also didn’t realize the direct relationship between cancer and exposure to pesticides, but she remembered having a lot of headaches due to the strong smell after the fields were sprayed, about 200 meters (660 feet) from her front door. “The [farmers] don’t give us any warning before spraying poison, and they usually start at daybreak. I have to close the house quickly or go into town,” she said.
Wals said the first time she learned of the link between developing breast cancer and exposure to pesticides was when someone from the oncology center in Cascavel municipality, where she received treatment, visited her at home and collected water and urine samples. “Until then, no one had told me about it. People in our community are used to the poison; one neighbor lives in the middle of the fields and sits outside, ‘eating that dust,’” she said.
Another study, led by Panis and published in 2022, found high levels of 11 types of pesticides in the water supplying 127 grain-producing municipalities across Paraná, with a combined population of 5.5 million. According to the study, at least 542 cases of cancer diagnosed among residents of the area between 2017 and 2019 may be related to this contamination.
“I underwent chemotherapy for six months and then I had surgery,” Wals said. “After 40 days, I started radiotherapy, and everything got well. Thank God I didn’t suffer much during that period.” She said she still has two years to go before she can be discharged from treatment.
Relationship between pesticides and cancer
Breast cancer has many causes, and studies indicate that exposure to pesticides may be one of them, according to Panis. She said the reactions of the human body vary according to factors such as exposure level, duration of contact, and individual susceptibility.
“We know that compounds such as glyphosate, 2,4-D and atrazine are related to breast, ovarian and thyroid cancer and others, as a result of the endocrine disruptions they cause,” she said. “There is evidence from animal studies that these pesticides directly affect DNA, in addition to altering hormone production. The body tries to repair this damage, but in some cases the repair system itself is compromised, making it impossible to correct the genetic material, for example.”
Dr. Monique Celeste Tavares, an oncologist at the A.C. Camargo Cancer Center in São Paulo, said the potential of pesticides such as glyphosate and atrazine to cause hormonal disorders is one of the factors explaining the link between these substances and breast cancer. “These agents can mimic or induce estrogen, which is one of the main hormones related to the development of breast cancer,” she said.
Dr. Fernando Maluf, a clinical oncologist and member of the management committee of the Oncology Center at Albert Einstein Hospital, also in São Paulo, said pesticide exposure can do great damage to genetic material. “These carcinogens affect DNA directly, interfering with the body’s protection mechanisms against the development of cancer,” he said. This effect, combined with changes in the immune system, can compromise the body’s ability to find and eliminate cancer cells.
Dr. Tavares said it’s important to study the risk of exposure to pesticides in rural populations. “Disseminating this information, especially in farming areas, is essential for these women to access measures to prevent exposure,” she said.
Environmental education for prevention
Panis and her team are currently carrying out a new initiative among female farmers in southwestern Paraná. It seeks to educate rural women at risk, with a focus on young women who haven’t yet been diagnosed with diseases related to exposure to pesticides.
To raise awareness among this group, the researchers are hosting lectures to disseminate the results of their study, and giving hand-on workshops to raise awareness about proper handling of pesticides, emphasizing the use of protective gloves when washing and decontaminating garments and PPE. The project also focuses on distributing PPE, although it faces funding challenges. Despite the equipment’s low cost, that can be an obstacle to its incorporation into farmers’ routines.
Panis said they’ve already trained more than 5,000 women in the area, providing information on the importance of wearing PPE when handling objects contaminated by pesticides, especially during household chores. “A simple rubber glove can reduce contamination rates, but raising awareness is not an easy task,” she said.
The project is currently sponsored by the Araucária Foundation, Brazil’s National Council for Scientific and Technological Development (CNPq), hydropower developer Itaipu Binacional, and local partners such as the Rotary Club and Cresol, in addition to the Paraná state government and the federal government, which funds the initiative.
“In this project, we take the results of the study to women and explain the risk to which they are exposed,” Panis said. “We provide a space for them to feel comfortable and talk.” She cites the importance of workshops that teach them how to wash clothes correctly and avoid contamination. “Today, the great strength of the work is this educational project. We show the data, raise an alert, and propose training on the use of PPE. We provide proper gloves for washing clothes, goggles and aprons, all suitable for handling pesticides.”
To assess whether the teachings are having an effect, Panis collected urine samples from a group of women who had previously declared themselves extremely exposed to pesticides, to see whether their levels of contamination after they’d attended workshops and training sessions had changed. “I want to show them that we can minimize this contamination just by wearing gloves,” Panis said. This stage of the study is underway now, and the group intends to present it soon, at an event that will be organized for all participants in southwestern Paraná next year.
Banner image: Pesticide spraying of tobacco crops in Paraná. Image courtesy of the Paraná Institute of Rural Development.
This story was first published here in Portuguese on Nov. 14, 2024.
Citations:
Panis, C., Candiotto, L. Z. P., Gaboardi, S. C., Teixeira, G. T., Alves, F. M., da Silva, J. C., … Lemos, B. (2024). Exposure to pesticides and breast cancer in an agricultural region in Brazil. Environmental Science & Technology, 58(24), 10470-10481. doi:10.1021/acs.est.3c08695
Pignati, W. A., de Souza e Lima, F. A. N., Sommerfeld de Lara, S., Montanari Correa, M. L., Barbosa, J. R., da Costa Leão, L. H., & Pignatti, M. G. (2017). Spatial distribution of pesticide use in Brazil: A strategy for health surveillance. Ciência & Saúde Coletiva, 22, 3281-3293. doi:10.1590/1413-812320172210.17742017
Cremonese, C. (2014). Exposure to pesticides and reproductive disorders: A study of rural workers, their families and young people in the city of Farroupilha – RS (Doctoral dissertation, Sérgio Arouca National School of Public Health, Rio de Janeiro, Brazil). Retrieved from https://www.arca.fiocruz.br/handle/icict/13159
Panis, C., Candiotto, L. Z. P., Gaboardi, S. C., Gurzenda, S., Cruz, J., Castro, M., & Lemos, B. (2022). Widespread pesticide contamination of drinking water and impact on cancer risk in Brazil. Environment International, 165, 107321. doi:10.1016/j.envint.2022.107321
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