An NIEHS-funded researcher is studying interventions to reduce the risk of spina bifida in Bangladeshi children. (Photo courtesy of Mattia Latini / iStock)
Approximately one in 2,000 children in the United States each year are born with spina bifida, a condition that occurs when the spinal cord doesn’t form properly and leaves nerves exposed. Spina bifida symptoms range from mild to severe and can include bladder and bowel problems, leg weakness, increased brain pressure, and paralysis.
Maitreyi Mazumdar, M.D., M.P.H., a pediatric neurologist at Boston Children’s Hospital, is investigating the connection between exposure to arsenic, a heavy metal commonly found in well water, and an increased risk for spina bifida. Her research team hypothesized that higher rates of spina bifida in Bangladesh were associated with exposure to arsenic from contaminated water and food supplies in the 1970s and 1980s. With funding from NIEHS, Mazumdar partnered with Bangladesh’s National Institute of Neurosciences & Hospital in 2016 to set up a robust health surveillance system in the country. There, her team collected blood, toenail, and tissue samples from approximately 600 children, half of whom have spina bifida, and their parents to better understand environmental risk factors for the condition. Mazumdar and her team analyzed the samples for arsenic and observed an association between parental arsenic exposure and offspring’s risk of developing spina bifida. Notably, they observed that a father’s arsenic exposure, along with a mother’s arsenic exposure, is associated with increased spina bifida risk.
Previous research found that the vitamin folate and its synthetic version, folic acid, may help reduce arsenic levels and lower the risk of spina bifida. However, the mechanism behind this effect was unknown. Mazumdar’s team found that women with gene variations that limited folate metabolism had a higher risk of offspring with spina bifida when the mothers also had high arsenic exposure.
Her current work aims to understand how arsenic affects DNA methylation and expression of genes involved in spinal cord development, and how folic acid may reverse genetic changes associated with arsenic exposure.
“Our work brings together two lines of research – understanding mechanisms of arsenic toxicity and understanding folic acid’s role in preventing spina bifida,” said Mazumdar. “By working on these questions together in one project, we were able to identify a population that had high risk of spina bifida and an intervention that could mitigate the additional risk conferred by arsenic.”
The research has already led to large-scale interventions within the Bangladeshi healthcare system. Mazumdar’s team conducts regular health information sessions with study participants and has developed and implemented a protocol for neurosurgeons to counsel families of spina bifida patients about folic acid supplements.
Mazumdar’s research has also steered national health policy. In 2024, her team presented their work to the Bangladesh Ministry of Health and Family Welfare, leading the government to pass resolutions recommending a national surveillance program for neural tube defects like spina bifida, the establishment of national dietary standards for folate, and a national media campaign to promote folic acid supplementation use with special attention to high arsenic areas.
Some flour companies in Bangladesh have responded to the call by fortifying flour with folic acid – a practice that is already required by the U.S. Food and Drug Administration and in many countries in Europe and South America.
“Arsenic contamination is a worldwide issue wherever people use well water, including in the U.S.,” said Mazumdar. “This research can help identify more interventions like folic acid supplementation to better protect children from the effects of arsenic toxicity, including spina bifida.”
