Table 1.

Experimental design

Experimental groups	Cd-D	Cd-F	Cd/Pb-D	Cd/Pb-F	Pb-D	Pb-F
Treatmenta	7 mg Cdb	7 mg Cdb	7 mg Cdb + 50 mg Pbc	7 mg Cdb + 50 mg Pbc	50 mg Pbc	50 mg Pbc
Source of metals	Drinking water	Feed	Drinking water	Feed	Drinking water	Feedd
Access to feedd	Free	Free	Free	Free	Free	Free
Access to drinking waterd	Free	Free	Free	Free	Free	Free
Number of rats	6	6	6	6	6	6
Duration of exposure	12 weeks	12 weeks	12 weeks	12 weeks	12 weeks	12 weeks
Euthanasiae	At 12 week	At 12 week	At 12 week	At 12 week	At 12 week	At 12 week

^aCd and Pb were supplied at doses not exceeding values equivalent to exposure of humans in exposure conditions, presented by [10–12]

^bCdCl₂ (cadmium chloride)

^c(CH₃COO)₂Pb (lead acetate)

^dfeed and drinking water intake were measured daily

^eStarved for 24 h, afterwards put down in CO₂ and having the spinal cord broken