Pesticides in soya farming may be behind leukaemia deaths in Brazil

The replacement of cow pastures with soya plantations in parts of Brazil has corresponded with an increase in leukaemia deaths among children, possibly due to pesticide exposure

By Christa Lesté-Lasserre

2 November 2023

Pesticide exposure from a rise in soya farming may have caused an increase in leukaemia deaths among children in Brazil

YASUYOSHI CHIBA/AFP via Getty Images

­­More children have died of leukaemia since large soya plantations have gradually replaced cattle farms in parts of Brazil, suggesting that pesticide exposure could be involved. However, the number of deaths is low and the exact cause hasn’t been determined.

Over the past two decades, parts of the Amazon have experienced a 20-fold expansion of soya farming, with previously cleared cow pastures converted into croplands. In the Cerrado, a vast savannah region which neighbours the Amazon, such farming has tripled.

Southern Brazil has a long-standing soya farming industry, with a transition in land use taking place more recently in the north and centre of the country. Brazil overall uses more pesticides than anywhere else.

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While carrying out agricultural research in the Amazon, Marin Skidmore at the University of Illinois Urbana-Champaign heard local people talking about a recent rise in childhood cancers, with previous research linking pesticide exposure to childhood leukaemia. “I wanted to see whether this phenomenon that I was hearing about on the ground would really bear out in the data,” she says.

Skidmore and her colleagues collected information about deaths due to lymphoid leukaemia in children under 10 years old – who usually develop a form of the condition called acute lymphoblastic leukaemia (ALL) – between 2004 and 2019 in rural areas of the Cerrado and Amazon, covering about 1.75 million square kilometres.

Healthcare workers in these places don’t necessarily report all lymphoid leukaemia diagnoses to government databases, says Skidmore. The researchers therefore focused on deaths, which were well documented, she says.