Synergistic effects and their potential significance for the influence of natural intensities of environmental factors on cell growth

Background

The assessment of the potential significance of synergistic interaction between adverse ecological factors acting together at the level of intensities found in the biosphere is still intriguing and unresolved problem.

Objective

This study aims to analyze synergistic effects for various biological objects, tests, and interacting agents to provide conclusive evidence of possible synergistic interactions of natural intensities of environmental factors on cell growth.

Methods

Four dose-effect curves were obtained for each object and interacting factors: after the individual action of agents, after their simultaneous action and theoretically expected curve after independent addition of the effects produced by each agent. The synergistic enhancement ratio (SER) and its dependence on intensities of agents were quantitatively estimated based on these curves.

Results

The extent of synergistic interaction was shown to be dependent on the intensity of physical factors or concentration of chemicals in such a manner that there were optimal conditions at which the greatest synergy may be achieved. The lesser the intensity of one of the agents applied, the smaller intensity of another agent has to be used to provide the highest synergistic interaction. In investigations where SER > 1, CI < 1.

Conclusion

The existence of optimal conditions providing the greatest synergistic effect and its dependence on the intensity of applied agents was demonstrated. Common patterns were identified. It is concluded that synergistic interactions are important for the evaluation of biological consequences and risk assessment from combined effects at low intensities of ionizing radiation, UV-light, electromagnetic fields, or small concentration of chemicals.