Neuroepidemiology Unit

The Neuroepidemiology Unit at Boston Children’s Hospital is led by Dr. Maitreyi Mazumdar. Researchers in this unit have evaluated environmental effects on children’s neurodevelopment for over thirty years, including several important studies on environmental lead (Pb) exposure and children’s cognitive performance. Several researchers from Boston Children’s Hopsital contributed to these projects, including Drs. Bellinger, Leviton, and Rabinowtiz.

Multiple projects are currently analyzing the ways in which environmental exposures influence health outcomes. Dr. Mazumdar has expertise in conducting research projects nationally and internationally, and several of the unit’s current studies are based in Bangladesh. There are multiple environmental issues of concern in Bangladesh, including (i) groundwater arsenic levels that are above the World Health Organization’s threshold of 10 micrograms per liter, (ii) elevated blood lead levels in children greater than 5 micrograms per deciliter, and (iii) low food security leading to increased rates of stunting and wasting. The findings from these studies have important global implications for any regions with these combinations of health concerns.

The Neuroepidemiology Unit approaches these research studies by combining expertise in neurology, environmental epidemiology, environmental sciences, exposure assessment, geographic information systems, and data management. Several of the Unit’s current studies are highlighted below:

Does arsenic increase risk of neural tube defects in a highly-exposed population? (NIEHS funded, R01 ES026317)

This novel case-control study in Bangladesh evaluates the ways in which maternal arsenic exposure, diet, genetics, and epigenetics interact to cause neural tube defects, specifically myelomeningocele and meningocele. Neural tube defects are a debilitating condition in which part of the neural tube does not close properly during development leading to several severe complications, including loss of pregnancy and infant mortality. The commonly recommended practice of using folic acid supplementation for pregnant women does not eliminate all neural tube defects. Multiple environmental, genetic, epigenetic, and dietary causes are possible. Previous research with animal models demonstrates that arsenic exposure can cause birth defects in a controlled laboratory setting. Preliminary data collected by the Neuroepidemiology Unit suggests that folic acid supplementation may be less effective as arsenic exposure increases, potentially due to increasing cellular competition for the methyl groups from folate. This NIEHS-R01 funded project is collecting data to test if this relationship between arsenic exposure and neural tube defects occurs in human populations. The findings from this study will help identify potential populations that are at an increased risk of developing neural tube defects caused by environmental exposures.

Arsenic related cystic fibrosis (NIEHS funded, R01 ES027825)

This novel cohort study in Bangladesh analyzes potential causative links between arsenic exposure and cystic fibrosis. Previous research in laboratory conditions found arsenic degraded the cystic fibrosis transmembrane regulator protein (CFTR). This protein serves an important function as a chloride channel that helps move fluids within cells, such as in the lungs, pancreas, and other organs. If someone has cystic fibrosis, a variant in the gene that codes for this protein interrupts the chloride channel’s ability to function. People with cystic fibrosis have reduced lung function. Part of the cystic fibrosis diagnosis includes collecting a sweat sample and quantifying the amount of chloride in the sweat. An elevated sweat chloride value, or an overall sweat conductivity value, is one piece of evidence used to diagnose someone with cystic fibrosis. A genetic test can also identify if this gene variant occurs. Preliminary data collected by the Neuroepidemiology Unit identified impaired lung function in Bangladeshi adults who had high sweat chloride values but lacked the gene variant that would cause cystic fibrosis. This NIEHS-R01 funded project is analyzing a cohort of Bangladeshi adults to compare arsenic exposure, sweat chloride, lung function, and CFTR protein expression to test if arsenic mimics some aspects of classic cystic fibrosis diagnoses. The findings from this study may identify novel mechanisms and outcomes of arsenic toxicity that will help identify populations at risk around the world.

Arsenic related cystic fibrosis: Administrative supplement (NIEHS funded, 3R01ES027825-02S1)

Longitudinal cohort data from Bangladeshi adults provides a novel data resource about arsenic exposure and lung function over time. This NIEHS-funded R01 administrative supplement is supporting a dynamic data management integration of four samplings of this cohort, including the R01 project discussed above. This project is being conducted through a collaboration with the Francis A. Countway Library of Medicine at Harvard University. The data management techniques resulting from this project will provide best practices, guidelines for researchers within and outside of NIEHS and Boston Children’s Hospital.

2019 International Neural Tube Defects conference (NICHD/NIEHS/NINDS funded, R13HD100191)

The Neuroepidemology Unit is actively involved in a leadership role within the broader neural tube defects research community. Dr. Mazumdar is the chair of the organizing committee for the 11th International Neural Tube Defects conference.

This international conference brings together researchers from around the world to discuss all aspects of neural tube defects, including causative mechanisms, novel model organisms, genetics, epigenetics, environmental and behavioral risk factors, clinical care, and potential preventative treatments.

The conference is generously supported by the Eunice Kennedy Shriver National Institute Of Child Health & Human Development (NICHD), the National Institute Of Environmental Health Sciences (NIEHS), and the National Institute Of Neurological Disorders And Stroke (NINDS).