Health impacts of pesticides in Brazil

© Lunaé Parracho/Reuters
Researchers and governmental agencies in Brazil are increasingly worried about the long-term health implications of the dramatic increases in pesticide use in the country and warn about an epidemic of chronic diseases, especially in regions where pesticide use is highest.

In 2015, the Brazilian National Cancer Agency (INCA) issued a strong statement warning of the serious health effects caused by massive pesticide use. The Institute, under the direct administration of the Ministry of Health, “marked [its] position against current pesticide use practices” and warned of the increased risk of chronic diseases, in particular infertility, impotence, miscarriages, malformations, neurotoxicity, hormonal deregulation, effects on the immune system and cancer. The INCA warned in particular that long-term exposure to “usually low doses” residues of multiple pesticides in food and the environment “may affect the whole population (…) and may lead to chronic health effects”.

Chronic diseases today “constitute the country’s greatest health concern” according to the Ministry of Health. Together they account for 72% of the causes of death. In contrast to recent decreases in the incidence of diseases like cardiovascular and chronic respiratory illnesses, “mortality rates related to diabetes and cancer have increased”, the Ministry observes. INCA expects some 600,000 new cases of cancer for 2019 – a 75% increase compared to 2000. Cancer is now the second cause of death in Brazil.

Marcia Sarpa de Campos Mello, toxicologist and researcher at INCA, says that the agency “is deeply concerned that pesticide exposure contributes to the growing cancer burden, particularly with regard to specific cancer types like those related to hormonal factors such as breast or prostate cancers”.

Prostate and breast cancer are the most common types of cancer in Brazil and both have increased significantly in recent years. In 2018, the Ministry of Health observed that prostate cancer mortality rates were particularly high in Brazil’s “agricultural production corridor” where production “strongly relies on the use of chemicals”. It also found that breast cancer mortality “stands out” in territories with high levels of exposure to agricultural chemicals. This is supported by several studies conducted in Brazil showing that both breast and prostate cancer are related to pesticides.

But other cancer types have also been associated with pesticide exposure. For example, the Ministry of Health has observed particularly high rates of Non-Hodgkin Lymphoma (NHL) in the agro-industrial territories. In 2018, INCA conducted a control study in its cancer hospital in Rio de Janeiro and found that patients were three times more likely to develop NHL if previously exposed to pesticides.

This finding was supported by another recent study which established that young agricultural workers in the south of Brazil face a twofold increase in the risk of dying from NHL compared to non-agricultural workers. And researchers concluded recently that the “sharp increase” in colon cancer mortality in Brazil from 2000 to 2012 was probably also linked to pesticides. A strong correlation was found between the amount of pesticides sold in the country and colon cancer mortality, suggesting that “pesticide exposure may be a risk factor for colon cancer”.

“We are not only concerned with cancer”, says Marcia Sarpa de Campos Mellos from INCA. “Several studies indicate that paternal exposure to pesticides can also lead to adverse birth outcomes.” Today, between three and five percent of newborns are affected by some form of congenital malformation in Brazil. Researchers found higher rates of birth defects in agricultural areas and among children whose parents were exposed to pesticides.