The Effect of Some
Organic Cyanides (Nitriles) on Fish
C. HENDERSON, in Charge Bioassay Studies
Q. H. PICKERING, Fisheries Research Biologist
A. E. LEMKE, Water Pollution Research Biologist
Public Health Service
Robert A . Taft Sanitary Engineering Center
Cincinnati, Ohio
INTRODUCTION
For the past several years, the Water Supply and Pollution Control Research Program at the Robert A. Taft Sanitary Engineering Center has conducted studies to characterize synthetic organic chemicals and industrial
wastes according to possible pollutional effects. Investigations have included:
effect on sewage treatment processes, susceptibility to biological treatment,
persistence in natural waters, effect on water treatment processes, production
of tastes and odors in water supplies, toxicity to mammals, and effects on
aquatic life.
Representatives of a group of industrially important chemicals, the organic cyanides or nitriles were the first selected for characterization. Studies
on their biochemical oxidation and effect on sewage treatment have been previously reported by Ludzack, etal(l,2). Studies of the effects of acryloni-
trile, adiponitrile, and oxydipropionitrile on laboratory rats have been reported by Svirbely and Floyd (3).
From the standpoint of effects on aquatic life, important criteria studied
include acute and chronic toxicity to fish and the tainting of edible fish flesh.
Experiments were conducted to characterize organic cyanides (Nitriles) by the
above criteria. The compounds tested and some of the pertinent characteristics are listed in Table I. All were soluble in water at the maximum test
concentrations.
TOXICITY TO FISH
Hydrocyanic acid, the simple metal cyanides, and some of the metallo-
cyanide complexes are known to be highly toxic to fish (4,5). While little
information is available on the toxicity of the organic cyanides, some of their
possible decomposition products, cyanides and ammonia, are known to be
toxic. Renn (6) has shown lactonitrile to be highly toxic (0.09 ppm as N) to
fresh water fish, primarily by its breakdown to hydrogen cyanide. Acryloni-
trile was reported to be considerably less toxic (10-18 ppm as N). Garrett (7)
has shown similar values when conducting bioassays with marine species of
fish.
Bioassays were made on six industrially important nitriles to determine
their acute toxicity to fish. Dilution waters with a wide range of characteristics and three different species of fish were used in the evaluations. Chemical
analyses were made to determine possible breakdown products from nitriles.
Long term, continuous flow experiments were conducted with lactonitrile and
acrylonitrile to determine possible chronic or accumulative effects.
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