Identifying susceptibility factors for methylmercury-induced developmental neurotoxicity

Abstract

Background and aim: Methylmercury (MeHg) exposures during pregnancy or childhood can cause developmental neurotoxicity (DNT), including cognitive, behavioral, and other effects. While many studies have reported on these effects, fewer have examined other factors that contribute to susceptibility to MeHg-induced DNT. The first objective of this project is to determine whether there are demographic, biological, psychosocial, societal, environmental, or other factors that may make developmentally exposed individuals more susceptible to these effects. A second objective is to develop a replicable approach for identifying susceptibility data in assessments of the health effects of chemicals. Methods: A systematic literature search for 2019-2021 aimed to identify all epidemiology studies that examined methylmercury exposure and DNT. Identified studies were then screened for susceptibility information at the title/abstract and full text levels by two reviewers. A search string was also developed and applied to title/abstracts to determine whether these studies could be identified without extensive screening. Susceptibility information was then summarized. Results: Data examining several potential susceptibility factors for MeHg were identified, including genetic polymorphisms, sex, maternal factors, nutritional status, and multi-chemical exposures. Conclusion: This project identifies potential susceptibility factors associated with MeHg and DNT. The methods applied to MeHg may be adapted and utilized for identifying and interpreting the literature on susceptibility factors for adverse health effects from other chemical exposures. Keywords: methylmercury, developmental neurotoxicity, susceptibility, systematic review, environmental justice Disclaimer: The views expressed in this abstract are those of the author and do not necessarily represent the views or the policies of the U.S. Environmental Protection Agency.