0.020 



0) 







Q. 

 (0 



E 



CD 



0.016 — 



0.012 — 



c/) 

 g 



k_ 





 O 



c 

 o 

 O 



0.008 — 



0.004 — 



0.000 



As Pb 



B 



Ni 



Cd Se Cr Zn 



Cu 



