Fig. 4.

LKMR estimated Mn–Zn interaction at three critical windows for ELEMENT data. Plot of the estimated interaction effect between Mn and Zn, holding Ba, Cr, and Li constant at median exposures.The interaction effect was calculated as follows. First, we estimated the exposure-response effect for high (75th) versus low (25th) manganese exposures, at high zinc levels. Next, we estimated the exposure-response effect for high versus low manganese exposures, at low zinc levels. The difference between the two estimated exposure-response effects quantifies the manganese-zinc interaction. All other metal exposures are held constant at their median values.