100 



-z 80 



CO 



< 



CO 



CO 



O 

 LU 

 Q_ 

 CO 



O 



CO 



< 



< 



O 



DMA 



As(lll) 



B 



DMA 



As(lll) 



B 



B 



DMA 

 Asdll 



DMA 



As( 



DMA 



DMA 



60 



Asdll) 



Asdll) 



As(V) 



40 



As(V) 



As(V) 



As(V) 



As(V) 



20 



As(V) 



CONTROL, 

 AMBIENT As 



12.5 jLtg/l 

 As(V) 



25 jLtg/l 

 AslV) 



Figure 5. — Arsenic speciation in culture media. Each species displayed as percent of total As. Bar A: stock culture media in 

 which no growth has taken place. Bar B: the same media, after 1 -week's growth. (DMA is dimethyl arsenic; As 

 (III) and As (V) signify arsenic in the plus three and five oxidation states, respectively.) 



Fitzgerald, W. F. 



1975. Mercury analyses in seawater using cold-trap pre- 

 concentration and gas phase detection. In: T. R. P. Gibb 

 (editor), Advances in chemistry series, No. 147, p. 99-109, 

 Am. Chem. Soc. 



1976. Mercury studies of seawater and rain: geothermal and 

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 Lexington, Mass. 



Fitzgerald, W. F., and C. D. Hunt. 



1974. Distribution of mercury in the surface micro-layer and 

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Fitzgerald, W. F., and W. B. Lyons. 



1975. Mercury concentrations in open-ocean waters: Sam- 

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Hoffman, E. J., and R. A. Duce. 



1977a. Organic carbon in marine atmospheric particulate 

 matter: concentration and particle size distribution. Geophys. 

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1977b. Alkali and alkaline Earth metal chemistry of marine 

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Hoffman, E. J., G. L. Hoffman, R. A. Duce. 



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