Toxins affect the environment and organisms in a variety of ways, from having little negative impact on certain abiotic factors or resistant organisms to killing animals and destroying major components of ecosystems. The extent of damage depends on the type and structure of the toxic substance; the age, the size, and the species of the organism; and the temperature and the physical and chemical characteristics of the environment (whether terrestrial or aquatic). Knowledge of how these factors interact is critical to understanding how best to prevent or reduce exposure or remove a toxin from the environment (environmental remediation).