Oak Ridge National Laboratory, Oak Ridge, Tennessee
Group Leader, Oak Ridge National Laboratory, Oak Ridge, Tennessee
Pages: 15 Published: Jan 1995
Inorganic borates and boric acid (boron-oxygen compounds) enter the environment as contaminants from the manufacture and industrial and household use of boron-containing compounds; from borax mining; and from coal, oil, and geothermal power generation. In general, boron compounds are more toxic to freshwater invertebrates than to freshwater fishes, with 48-hr LC50 values ranging from <52–226 mg B/L in the water flea (Daphnia magna) and 96-hr LC50 values ranging from 332–979 mg B/L in fathead minnows (Pimephales promelas) and mosquitofish (Gambusia affinis). Data also indicate that boron compounds are more toxic to saltwater crustaceans and fish than to freshwater species, with a 24-hr LC50 of 28.35 mg B/L in the saltwater isopod (Limnoria lignorum) and a 96-hr LC50 of 74 mg B/L in dab (Limanda limanda). A comparison of the acute toxicity of boron-oxygen compounds to adult and early developmental stages of fishes and invertebrates indicates that most species are more sensitive to sodium borates (sodium perborate > borax) than to boric acid. This increased toxicity may be attributed to a pH shift into the alkaline range, which in fish results in increased mucus formation and crippling behavior.
Sodium borate, Boric acid, Aquatic toxicity, Water quality criteria, Freshwater fish, amphibians, invertebrates, Saltwater fish and invertebrates
Paper ID: STP12696S