Abstract
Metals are ubiquitous, and concentrations of them are at a level at which risks to aquatic biota cannot be ignored. There are a lot of toxicity data for metals, and those tests revealed that the toxicities of metals vary depending on water chemistry. Ecological risk assessment（ERA）of metals has long been obstructed due to the large uncertainty. After a powerful troubleshooter, a biotic ligand model（BLM）which predicts the varying toxicity, has been developed, there are much progresses in the ERA of metals. We first provide a brief review on the history of the ERA of metals. Then we introduce our recent results of the population level assessments and discuss their implications for future ERA. At the end, we argue what we need to develop more ecologically relevant ERAs.
