Pollution :) Since Abiotic means non living.
Bacteria: Living
Food (worms or smaller fish): Living
Predators: Living
Pollution (dirt, trash, or other stuff): Non Living
Annelids have neither an external or an internal shell. Examples of annelids are
earthworms and leeches.
I think that the Risk assessment depends on medicine. Here's some extra details: the PROCESS by which HAZARD, exposure and risk are determined. The four steps of risk assessment are Hazard identification<span>Dose-response assessment
Exposure assessment
Risk characterization</span>