Ecological effects - trdoer40205

into the skin where it may remain rather than entering the systemic circulation.

Following inhalation exposure, nickel tends to accumulate in the lungs. Nickel

can cross the placenta and it can accumulate in breastmilk. Regardless of the

exposure route, absorbed nickel is excreted in the urine.

Ecological effects

a. Bioaccumulation. Nickel concentrations in plants are generally low,

< 150 mg/kg dry weight, but occasional reports will show much higher

concentrations of 150 to 700 mg/kg. Likewise, invertebrate

concentrations are low, usually < 5 mg/kg. Nickel cannot be considered

a significant, widespread contaminant except at certain site-specific

points. Uptake in invertebrates occurred principally through the water

and ingested particulate nickel was excreted. In fish, concentrations

again are generally low, < 0.5 mg/kg wet weight, but instances of higher

concentrations do exist near polluted areas (1 to 2 mg/kg wet weight).

b. Toxic Effects to Aquatic Organisms. Nickel (Ni2+) is considered

moderately to highly toxic to most aquatic plant species. To

invertebrates, Ni2+ is one of the least toxic inorganic agents. To both

marine and freshwater fish, Ni2+ is relatively nontoxic but when exposed

to low levels over extended periods effects include reduced skeletal

calcification and reduced diffusion capacity of gills. Both acute and

chronic toxicity of Ni2+ is strongly related to water hardness.

D53

Appendix D Toxicological Profiles