TOXICITY OF RESIDUAL CHLORINE COMPOUNDS TO AQUATIC ORGANISMS

摘要

Laboratory studies on the acute and chronic toxicity of chlorine and inorganic chloramines to trout, salmon, minnows, bullhead, largemouth bass, and bluegill were conducted. Acute toxicity under continuous and inter¬mittent patterns of exposure ás well as behavioral, reproduction, development, and growth responses to low level exposures to residual chlorine compounds were determined. But not all patterns of toxicant exposure or all responses of all fish species were studied. Acute and chronic toxicities of chloramines to crayfish were investigated. Algae, invertebrates, including insects, and juvenile salmon were exposed continuously to relatively low levels of residual chloramine compounds in laboratory stream communities. The acute toxicities of inorganic chloramines, as measured by 96-hour LC50 values, were less than 100 yg/1 for salmonids and were a function of life history stage, body size, and some water quality conditions. Whereas adult trout may live indefinitely at concentrations near 50 yg/1, the LC50 values for late developmental stages—fry and very small juveniles—were not much above this concentration. Effects on growth of alevins and juveniles had threshold concentration values between about 10 and 22 yg/1, effects being quite marked at 22 yg/1.