Functional and pathological responses of selected aquatic organisms to chrysotile asbestos

Functional and pathological responses of larval, juvenile, and adult Asiatic clams (Corbicula sp.), juvenile and adult fathead minnows (Pimephales promelas), and egg, larval and juvenile Japanese Medaka (Oryzias latipes) to chrysotile asbestos were investigated in 96-hour to 91-day tests. Chrysotile significantly reduced siphoning activity and shell growth of adult clams and siphoning, shell growth, and weight gain of juveniles at 10⁵ fibers/liter during 30-day tests. Larval Corbicula suffered significantly greater mortality and lower release by brooding adults at 10²-10⁸ fibers/liter. Adult and juvenile Corbicula exposed to 10⁸ fibers/liter for 30 days exhibited deteriorated gill tissue and significantly greater tissue water content. Corbicula accumulated up to 1000 fibers/mg in visceral tissue at 10⁸ fibers/liter. Clams collected from the California Aqueduct System exposed to 10⁹ fibers/liter accumulated up to 10⁵ fibers/mg in viscera. Corbicula can be used as a monitor for chrysotile contamination due to its ability to concentrate fibers.

Adult and juvenile fathead minnows did not suffer acute toxicity at 10¹² fibers/liter and differential mortality relative to controls up to 10⁸ fibers/liter for 30 days. At the conclusion of the 30-day tests the length, weight, and swimming performance of adult minnows exposed to asbestos were not significantly affected relative to controls. Juvenile minnows exposed to 10⁶-10⁸ fibers/liter had significantly lower weight. Fish exposed to 10⁸ fibers/liter for 30 days accumulated up to 390 fibers/mg in kidney tissue.

Egg and larval Medaka were exposed to 0-10¹⁰ fibers/liter of chrysotile until hatching and for thirteen weeks, respectively. Eggs responded erratically to asbestos exposure and no conclusive trends could be drawn. Larval Medaka exposed to 10⁶-10¹⁰ fibers/liter had reduced growth by 14 days. Fish exposed to 10¹⁰ fibers/liter suffered 100% mortality by 60 days. Fish exposed to asbestos developed epidermal tumors, thickened epidermal tissue, increased mucous cell density in the intestinal tract, constricted kidney tubules, and abnormal levels of lipid and endoplasmic reticulum in the liver. Maximum asbestos uptake occurred in fish exposed to 10⁸ fibers/liter for 91 days (400 fibers/mg).

The extent of damage to fish and clams at levels greater than 10⁴ fibers/liter in the laboratory suggests that aquatically transmitted asbestos is a potential hazard to these species in the field.