The degree to which toxic substances or other pollutants are present in sediments or elsewhere in the ecosystem to affect or be taken up by organisms. Some pollutants might be "bound up" or unavailable because they are attached to clay particles or are buried by sediment. The amount of oxygen, pH, temperature, and other conditions in the water can affect availability.

the ability of a substance to affect organisms.

Degree to which chemicals can be taken up by organisms.

the availability of a pollutant to be used by living organisms.

existence of a substance in a physical and chemical state which can be taken up by living organisms

The availability of chemicals to potentially biodegradative microorganisms; the availability of a toxic chemical to cause an adverse effect in higher life forms (e.g., humans).

The fraction of chemical present that is available for uptake by aquatic organisms.

the availability of a compound for biodegradation, influenced by the compound's location relative to microorganisms and its ability to dissolve in water.

The capacity of a chemical constituent to be taken up by living organisms either through physical contact or by ingestion.

The degree to which toxic substances or other pollutants present in the environment are available to potentially biodegradative microorganisms. Some pollutants might be "bound up" or unavailable because they are attached to clay particles or are buried by sediment. The amount of oxygen, pH, temperature, and other conditions in the water can affect availability.

(4) a property of a substance which makes it accessible and potentially able to affect an organism's health.