Temporal trends in mortality to (A) DDT; (B) deltamethrin and (C) permethrin in the four ecological zones of Côte d’Ivoire. Solid lines indicate significant correlations, dashed lines are non-significant. In all plots quantitative analysis was performed only on ecozones 1 and 2. In all analyses there was a significant effect of year and year × ecozone on mortality. In (C) open symbols show data for bioassays with a concentration of 1% and filled circles with the current WHO standard of 0.75%.