OBSERVATIONS FROM A 6 MONTH STUDY ON THE EFFECT OF BIODEGRADATION PROCESSES IN SEDIMENT ON THE TOXICITY POTENTIAL OF TARGETED CHEMICALS

To illustrate the difficulties and problems involved in assessing the effect of biodegradation processes in sediments on the toxicity potent ial of targeted chemicals, a study was carried out to examine the rela tionship of aerobic and anaerobic biodegradation (on the ecotoxicity) of two priority organic chemicals (nonylphenol and aniline). The chemi cals were spiked into heavily polluted Hamilton Harbour sediments and over a period of 6 six months the changes in toxicity and genotoxicity (as assessed by 10 short-term bioassays) of the spiked sediments and their metabolites were monitored. The results indicated that under ana erobic conditions nonylphenol levels increased in concentration, while aniline quickly degraded under aerobic conditions and a little slower under anaerobic conditions. The data also revealed the inherent wide variability in toxicant distribution in homogenized sediment samples. (C) 1998 by John Wiley & Sons, Inc.