TABLE 2. THE INFLUENCE OF FACTORS ON THE CHARACTER OF ACTION OF THE 

 POLLUTANTS ON AQUATIC ORGANISMS 



Type of Influence 



Factors 



Character of Influence 



On properties 

 of pollutants. 



CO ? content in water, 



Rate of oxidation of pollu- 

 tants. 



Content of mineral 

 substances in water. 



Coagulation of some substances, 

 neutralisation of acids and 

 alkalis. 



Content of organic 

 matter. 



Formation of complex compounds 

 with pollutants absorption. 



On the time and 

 condition of the 

 contact or orga- 

 nisms with pollu- 

 tants. 



pH of the water. 



COo content. 



Dynamics of water 

 masses (velocity of 

 currents, convection, 

 stagnation, etc.). 



Change in the degree of disso- 

 ciation of pollutants, and in 

 their toxicity. 



Change in the direction of 

 chemical reactions and buffer 

 properties of water. 



Dilution of pollutants, possi- 

 bility of their concentrating 

 in certain parts in water or in 

 bottom sediments. 



Distribution and mi- 

 grations of organisms 

 in a water-body. 



Possibility of organisms mi- 

 grating into polluted water. 



On sensitivity of 

 organisms to the 



action 

 cants 



of toxi- 



Size, age, sex. 



Differences in sensitivity of 

 stages. Usually males are more 

 sensitive than females. 



Contents of other sub- 

 stances in water. 



Discrepancy between re- 

 quirements of organism 

 and environmental con- 

 ditions . 



Antagonism and synergism of 

 toxic substances. 



Increasing sensitivity to in- 

 juring factors, including the 

 action of pollutants. 



Weakening of organisms 

 due to starvation, par- 

 asites, infections, etc. 



Stress conditions of 

 organism. 



The same as above. 



Changes in time of reaction and 

 in intensity of injuring. 



88 



