7092

• UCREFRP Catalog Number: 7092
• Author: Eisler, R.
• Title: Arsenic Hazards to Fish, Wildlife, and Invertebrates
• USFW Year: 1988.
• USFW - Doc Type: A Synoptic Review.
• Copyright Material: NO

arsenic cycle only by causing localized high concentrations (NAS 1977). The
speciation of arsenic in the environment is affected partly by indiscriminate
biological uptake, which consumes about 20% of the dissolved arsenate pool and
results in measurable concentrations of reduced and methylated arsenic
species. The overall arsenic cycle is similar to the phosphate cycle;
however, regeneration time for arsenic is much slower--on the order of several
months (Sanders 1980). The ubiquity of arsenic in the environment is evidence
of the redistribution processes that have been operating since early geologic
time (Woolson 1975). A prehuman steady state solution to the global arsenic
cycle (Austin and Millward 1984) indicates that major reservoirs of arsenic
(in kilotons) are magma (50 billion), sediments (25 billion), oceanic deep
waters (1.56 million), land (1.4 million), and ocean mixed layers (270,000);
minor amounts occur in ocean particulates (100), and in continental (2.5) and
marine tropospheres (0.069). Arsenic is significantly mobilized from the land
to the troposphere by both natural and anthropogenic processes. Industrial
emissions account for about 30% of the present day burden of arsenic in the
troposphere (Austin and Millward 1984). Agronomic ecosystems, for example, may
receive arsenic from agricultural sources such as organic herbicides,
irrigation waters, and fertilizers, and from such nonagricultural sources as
fossil fuels and industrial and municipal wastes (Woolson 1975). Arsenic is
mobile and nonaccumulative in air, plant, and water phases of agronomic
ecosystems; arsenicals sometimes accumulate in soils, but redistribution
mechanisms usually preclude hazardous accumulations (Woolson 1975).
Arsenic compounds have been used in medicine since the time of
Hippocrates, ca. 400 BC (Woolson 1975). Inorganic arsenicals have been used
for centuries, and organoarsenicals for at least a century in the treatment of
syphylis, yaws, amoebic dysentery, and trypanosomiasis (NAS 1977). During the
period 1200 to 1650, however, arsenic was used extensively in homicides (NRCC
1978). In 1815, the first accidental death was reported from arsine (AsH )
poisoning, and in 1900-1903 accidental poisonings from consumption
arsenic-contaminated beer were widely reported (NRCC 1978). In 1938, it was
established that arsenic can counteract selenium toxicity (NRCC 1978). The
introduction of arsphenamine, an organoarsenical, to control venereal disease
earlier this century gave rise to intensive research by organic chemists,
which resulted in the synthesis of at least 32,000 arsenic compounds. But the
advent of penicillin and other newer drugs nearly eliminated the use of
organic arsenicals as human therapeutic agents (EPA 1980). Arsenical drugs
are still used in treating certain tropical diseases, such as African sleeping
sickness and amoebic dysentery, and are used in veterinary medicine to treat
parasitic diseases, including filariasis in dogs (Canis familiaris) and
blackhead in turkeys (Meleagris gallopavo) and chickens, Gallus spp. (NAS
1977). Today, abnormal sources of arsenic that can enter the food chain from
plants or animals include arsenical pesticides such as lead arsenate; arsenic
acid, HAsO ; sodium arsenite, NaAs0; sodium arsenate, Na2As04; and cacodylic
acid, (CH3J2As(OH) (NAS 1977). 2
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