The study identifies a strong relationship between prenatal and early childhood exposure to mercury and autistic behaviors in five-year-olds.

Lead author Jia Ryu and coauthors acknowledge mercury's potential for neurotoxicity straight away but choose to characterize previous findings on the mercury-autism relationship as "inconsistent." They attribute the seeming lack of consistency, in part, to methodological issues, especially flagging problematic cross-sectional study designs that measure autistic behaviors and mercury levels (in either blood or hair) at a single point in time. To rectify these methodological weaknesses, Ryu and coauthors report on data from a multi-region longitudinal study in the Republic of Korea called the Mothers and Children's Environmental Health (MOCEH) study.