Analysis of the ECETOC aquatic toxicity (EAT) database - III - Comparative toxicity of chemical substances to different life stages of aquatic organisms

In the context of current risk assessment procedures, the ECETOC Aquatic Toxicity (EAT) database has been used to assess the comparative sensitivity of different life stages of aquatic organisms to a range of chemical substances. Both EC50 and NOEC data were analysed using Hazen percentiles in order to compare key life stages of both fish and aquatic invertebrates (no data available on aquatic algae or plants). Based on fish NOEC data, larvae were more sensitive (ratio > 2.0) than embryos for 68% of substances, while fish larvae were of greater than or equal sensitivity to juvenile fish for 83% of substances. Based on fish EC50 data (NOECs unavailable), juveniles were more sensitive than adults for 92% of substances. For a limited number of available substances, fish embryo-larval tests (as NOECs) were of greater than or equal sensitivity to lifecycle tests for 42% of substances. Based on EC50 data (NOECs unavailable), aquatic invertebrate larvae were of greater than or equal sensitivity to juvenile invertebrates for 66% of substances, while the juveniles were of greater than or equal sensitivity to adults for 54% of substances. Full details are presented for the calculated sensitivity ratios for individual organic and inorganic substances. The results are discussed with respect to current ecotoxicology test procedures and recommendations made for future work in this important area of environmental risk assessment. (C) 1997 Elsevier Science Ltd.