Determination of ecological impacts Flashcards
Toxicity
Capacity to cause harm to a living organism.
LD50/LC50
The median lethal dose (LD50) and the median lethal concentration (LC50) describe the level of exposure (dose or concentration) that kill the 50 percent population.
ED50/EC50
The median effect dose or concentration describes the level of exposure that causes a defined effect to 50 percent of population.
NOEC/NOED
No observed effect level is the general term for the dose or concentration at which a test chemical dose not cause an effect that is statistically significant from the control.
Bioaccumulation
The extent to which pollutant accumulate over time in the tissues of organisms (leaves, roots, bones, body fat) through any route, including respiration, ingestion, or direct contact is referred to as bioaccumulation.
Biological half life
The time the pollutant takes to remove 50 percent of its quantity in a specified tissue, organ or any other specified biota as a result of biological processes.
Water pollution
‘Addition of certain substances to the water such as organic, inorganic, biological, radiological, heat, which degrades the quality of water so that it becomes unfit for use’.
Putrescibility
Putrescibility is the process of decomposition of organic matter present in water by microorganisms using oxygen.
Biological oxygen demand
BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water. It is expressed in milligrams of oxygen per liter of water.
Chemical oxygen demand
It is the measure of oxygen equivalent of the requirement of oxidation of total organic matter (i.e. biodegradable and non-biodegradable) present in water.
Methyl Mercury
A crippling deformity called Minamata disease due to consumption of fish captured from mercury contaminated Minamata Bay in Japan was detected in 1952.
