Biochem metyl Hg

ant

nat

Anthropogenic and natural inputs

Sediments

Inorganic minerał layers (inactive)

-&-

Upper sediments (biochemically activcO

HgS

^sorptir^°'

K = 1 x 10'* f

m upper sediments

iropogemc iral inputs

Food

chain

b, h\)

(CH,)jKg

volatilise

RHgX

anthropogeni & natural in

puts

Hydrosphere

precipitation

Atmosphere —■ ► Hg° + 2CH₃ Fig 5.9 Chemical and biochemical pathways of mercury in the hydrosphere a = Iow pH, b = bacterial, ba = high pFI, c = Chemical, hx> = radiation, o = oxidation, aerobic, r = reduction, anaerobic, s = H₂S. Source; Fergusson, 1982 [19].

h\)