Fig. 4. Gut tissue Cu concentration (µmol g^–1 wet mass) over the exposure period and the proportional contribution (%) to total body Cu burden. Percentage data were transformed to arc sin for statistical analysis. Values are means ± S.E.M.; N=15 for weeks 0, 2 and 4, and N=9 for week 7 for each treatment. Diamonds, low waterborne Cu and low dietary Cu; triangles, low waterborne Cu and normal dietary Cu; open circles, normal waterborne Cu and low dietary Cu; filled circles, normal waterborne Cu and normal dietary Cu; squares, normal waterborne Cu and high dietary Cu level. *Significantly higher level, significantly lower level relative to the group on normal levels of water Cu and dietary Cu (ANOVA, P<0.05).