38 N. J. Mosquito Extermination Association 



extermination work, becomes one that will require the serious 

 consideration of those engaged in this work. 



It would be difficult indeed to discover a situation where we 

 are less armed to meet the conditions of pollution caused by the 

 discharging of industrial wastes and sewage into streams drain- 

 ing populous areas. The practical working limit is oil spraying, 

 and this is limited in its effect as a temporary expedient on large 

 areas. It is a case of getting minimum results from maximum 

 effort. Another difficult matter is to furnish a satisfactory gen- 

 eral solution of the problem because there are rather a large num- 

 ber of specific problems, differing among themselves in the vari- 

 ous kinds and conditions of the polluting material discharged 

 into rivers, streams and ponds. 



From the reports made at different times and places on the 

 investigation of pollution of rivers and streams, there is disclosed 

 such a diversity in chemical characteristics in the pollution caused 

 by discharging industrial wastes into rivers and streams that to 

 those engaged in mosquito-extermination work it constitutes a 

 complex problem, which up to the present time has been a very 

 difficult one to solve in regard to its influence on mosquito breed- 

 ing. 



It is hardly possible at this time to enumerate the chemical 

 character and polluting effects of all trade wastes, but among 

 others is the discharge fromi tanneries of tannic acid, limie and 

 clay waste, which cause discoloration and affect fish life. From 

 woolen manufacturing mills, wool scourings and spent dyes 

 markedly discolor the water in an offensive manner, and the 

 visible effects are very objectionable. The spent lye discharged 

 from soap works, and nitric and sulfuric acid from ammunition 

 and powder factories destroy all insect life and fish. Paper mill 

 wastes from the sulfite mills have a striking effect on rivers and 

 streams, and materially change their character. This combina- 

 tion of various wastes discharged into rivers and streams will 

 require considerable study to determine its effect on mosquito- 

 extermination work. 



Let me quote from notes made by H. R. Carter, assistant 

 surgeon general of the United States Public Health Service, on 

 the pollution of streams at Columbus, Georgia. 



