The electroencephalogram (EEG) reflects brain electrical activity. A flat (isoelectric) EEG, which is usually recorded during very deep coma, is considered to be a turning point between a living brain and a deceased brain. Therefore the isoelectric EEG constitutes, together with evidence of irreversible structural brain damage, one of the criteria for the assessment of brain death.
Thus, the cloudier the water, the greater the turbidity. As algae, sediments, or solid wastes increase in the water, so does turbidity. Turbidity affects organisms that are directly dependent on light, like aquatic plants, because it limits their ability to carry out photosynthesis. This, in turn, affects other organisms that depend on these plants for food and oxygen. Scientists often consider turbidity of the water in connection with other factors to get a better understanding of its causes and consequences.
Effects of lead on micro-organisms. Evidence exists to show that lead at the concentrations occasionally found near roadsides (i.e., 10,000 - 40,000 ppm dry weight), can wipe out populations of bacteria and fungi on leaf surfaces and in soil.