Author: Emma Loewe
Institution: Duke University
One morning in 2004, molecular geneticist Lisa Satterwhite was sitting at her office in Duke Hospital’s Cardiology Department when she came across a newspaper article that would ultimately shape the trajectory of her research.
Lisa was struck by the story of Carlitos Herrera-Candelario, a child born without arms or legs. Carlitos was a victim of tetra-amelia, a rare disorder characterized by missing limbs, and he also suffered spinal and lung deformities. Amazingly, Carlitos was one of three babies to be born with severe birth defects on the farm his parents worked for. They blamed the farm’s unmonitored pesticide applications for their son’s deformity and sought to challenge their employers in court.
“It’s time to make sure this doesn’t happen again,” Lisa says, remembering her first encounter with the Carlitos’ story. “We have to stop everything we’re doing and do something about this – I’m going to be the person to get started.”
Thus began Lisa’s quest to scientifically link illness in the migrant farming community to pesticide applications. Initial remote studies eventually culminated in an on-the-ground research effort in the summer of 2010.
“There are really strong associations between pesticides and Alzheimer’s, Parkinson’s, ALS, a lot of neuro-muscular diseases, birth defects and all kinds of cancers. What they don’t know is if the pesticides are the causative agents,” Lisa explains.
Based in eastern North Carolina, her study collected blood and urine samples from a group of Latino field farmers and compared them to those of poultry plant workers. Lisa and her team analyzed the urine for pesticide metabolites and the blood for any trace of disease. What they found were specific gene expressions that changed with the renal pesticide levels—a direct link between genetics and pesticide exposure.
Off to an encouraging start, the team set out to further refine their test groups. Initial results revealed that the poultry workers were also exposed to high levels of certain pesticides, probably from the chicken feed they were using. These trace chemicals presented a challenge since Lisa originally intended to use the poultry workers as her pesticide-free control population. After realizing the poultry workers also experienced health risks from pesticide exposure, Lisa replaced them with a more consistent control group: construction workers. She also added farm workers working in tobacco to her study for their unique duel exposure to both pesticides and nicotine.
The team returned to the field this summer to take blood and urine samples from both these new groups and the original farm workers. Lisa is currently working to secure the funding necessary to process the collected data and hopes that the results will be consistent with her hypothesis that pesticide exposure and illness are inextricably linked.
The results could then be used as the basis for a blood test that checks for early stage neurodegenerative diseases stemming from pesticide exposures. By creating a test to detect preventable illnesses, Lisa hopes to encourage laws that set stricter testing standards on synthetic chemicals.
A dramatic shift in chemical regulation could lessen the likelihood of deformities like Carlitos’ in farming communities across the country. Though Carlitos’ lawsuit settlement provided his family enough money to pay for his medical bills, his parents’ employer never admitted any wrongdoing throughout the litigation.
“There are several fronts – there’s research that is needed to convince people and then there’s policy,” Lisa says. “There’s been a lot of research done and now I think we need a major policy change.”
Lisa asserts that her ultimate career goal is to end environmentally-caused chronic disease in her lifetime. She seeks to combine on-the-ground research with laboratory analysis and policy lobbying to ensure that Carlitos’ story does not repeat itself.