Propreties Pfollutants 3 Flashcards
What does bioaccumulation means
Bioaccumulation is the process by which pollutants are absorbed and stored within living organisms
Why tend pollutants that are liposoluble to bioaccumulate
They tend to bioaccumulate because they build up in lipid store
Name some pollutants that bioaccumulate
Chlorinated organic compounds such as organochlorine insecticides, dioxins and PCBs and heavy metals such as lead and mercury
What is meant by biomagnification ?
It is the progressive bioaccumulation of a material along a food chain.
Explain briefly the processus of bioaccumulation. Why do a pollutant become increasingly concentrated?
Pollutants that bioaccumulate and are stored within the body of an organism may be ingested (eaten) by the organisms in the next tropic level the food chain where they. Ay also be stored. Because predators eat large quantities of their prey over a period of time, the pollutants will become increasingly concentrated as more small doses are added
What is meant by the term synergism?
Synergism is the process where the presence of two materials produces a greater effect than the sum of their individual effects.
Give some examples of synergistic pollutants
Oxides of nitrogen and sulfur and zinc and cadmium
What is a mutagen
A material or form of energy that can cause chemical changes in DNA
What can a change to DNA cause to a cell?
A change in DNA may cause a cell to behave abnormally. The possible consequences depend upon the type of cell affected
What can DNA changes causes to body cells?
May result in the cell becoming cancerous
What can happen to a sperm or egg if it is affected by a mutagen?
Any baby produced may have congenital birth abnomalities that could also be passed on to future generations
Name some examples of mutagenic pollutants
Mutagenic pollutant include ionizing radiation, asbestos, dioxins and PCBs
What is a carcinogen?
A carcinogen is a mutagen that causes the body cells to start multiply in an uncontrolled way
What is called a cancerous tumour?
The cell multiplication by a carcinogen can be slow or fast. The cell produced do not carry out the normal functions of the tissue cells where they are found. Such growth is called a cancerous tumour
How can a tumour cause health problem?
By preventing the function of the normal tissue cells
