This study investigated the effects of mercury levels on brain morphometry and neurobehavioral performance in young adults. Hair mercury levels were analyzed in 920 healthy young adults, along with regional gray matter volume (rGMV), regional white matter volume (rWMV), fractional anisotropy (FA), mean diffusivity (MD), cognitive functions, and depression. Greater hair mercury levels were weakly but significantly associated with diminished cognitive performance (particularly speed measures), lower depressive tendency, lower rGMV in the thalamus and hippocampus, lower rWMV in widespread areas, greater FA in bilaterally distributed white matter areas, and lower MD in gray and white matter areas. These findings suggest that even normal mercury exposure levels may be associated with altered brain structures and neurobehavioral performance.

Hikaru Takeuchi, Yuka Shiota, Ken Yaoi, Yasuyuki Taki, Rui Nouchi, Ryoichi Yokoyama, Yuka Kotozaki, Seishu Nakagawa, Atsushi Sekiguchi, Kunio Iizuka, Sugiko Hanawa, Tsuyoshi Araki, Carlos Makoto Miyauchi, Kohei Sakaki, Takayuki Nozawa, Shigeyuki Ikeda, Susumu Yokota, Daniele Magistro, Yuko Sassa, Ryuta Kawashima