earticle

영어

The whole biota is constantly exposed to ionizing radiation and other environmental factors.
These agents are sometimes able to damage biological objects. The risk assessment is usually
performed assuming that any harmful factor acts independently of others. However, the combined
exposure to harmful agents might result in a higher effect than expected from the addition of the
effects produced by each agent. A generalized concept has been developed from the combined
actions of heat with various factors1). Synergistic interaction is expected to result from an
additional effective damage arisen from the interaction of sublesions induced by both agents.
These sublesions are considered to be ineffective after each agent taken individually. The
additional damage responsible for the synergistic effect seems to be irreversible2). This concept
was used to construct a theoretical model for synergism between two different factors. The
model predicted that the synergy could be observed only within a definite range of the ratio of
damages produced by heat and another environmental factor applied simultaneously. Predictions
could be made for the greatest value of the synergy and condition under which it can be achieved.