3.5 



c 

 o 



-t-> 



03 



a 



CD 



2» 2.5 



O i- 



i 



03 ^ 



£ 0> 2 



o 



* 1 .5 



o 



CD 

 O 



1 



85 86 



87 88 89 90 



year 



9 1 



Figure 4b. Annual geometric mean concentrations of selected chemicals in mollusks. 



if) 



<z 

 o 



1 0.5 



™ 1 0. 1 



c 



CD 



O >- 



C C_ 



O "O 



O I 



c o 



CD zj> 



CD 



E 

 o 



CD 



9.7 



9.3 



8.9 



8.5 



85 86 87 88 89 90 9 1 



year 



Figure 4c. Annual geometric mean concentrations of selected chemicals in mollusks. 



18 



