Possible Health Effects 



Although the effects of inhaled asbestos are reasonably well docu- 

 mented, the effects of ingested asbestos have only recently come under 

 study. The Great Lakes Research Advisory Board indicates the following oc- 

 cupational hazards: 



1. Asbestosis; increased fibrous tissue growth of the lung. 

 Disease will appear after 10-40 years of occupational 

 exposure. 



2. Pleural calcification; a deposition of insoluble salts 

 in the lung lining. Occurs after an approximate 20 year 

 latency period. 



3. Mesothelioma of the chest and abdominal cavity lining; 

 with a latency period of 20-40 years, this disease was 

 considered, until recently, quite rare. 



Much less is known regarding ingested asbestos. It has been shown 

 that the high rate of stomach cancer in Japanese is linked to their use of 

 rice dusted with asbestositic talc (Merliss, 1971). Laboratory tests em- 

 ploying rats show that asbestos will accumulate in the brain and in tissue 

 surrounding the small intestine. It may also cause malignant tumors in 

 the kidney, lymph-nodes and brain (Pontefract and Cunningham, 1973). How- 

 ever, present knowledge of public health aspects of asbestos in drinking 

 water supplies is inadequate. In consideration of the potential of this 

 problem, the significance of a possible 20 year delay following even short- 

 term exposure must be given proper perspective (U.S. Circuit Court of 

 Appeals, 1974). 



Considering direct biochemical effects to Lake Superior, taconite tail- 

 ings deposition has shown to bring about the following results (Federal 

 Water Pollution Control Administration, 1970): 



1. A reduction in the abundance of fish food production suf- 

 ficient to create five (5) percent reduction in commer- 

 cial and sport fishing. 



2. Chemical analysis projections, based upon daily discharge 

 of 67,000 tons of tailings, indicates daily discharge of 

 copper, nickel, zinc, lead, chromium, phosphorus and man- 

 ganese ranging from 1,860 kilograms to 285,310 kilograms 

 (4,100 to 629,000 pounds). 



RED CLAY TURBIDITY 



Based on the discharge analysis of major tributary systems, open lake 

 turbidity and shoreline recession rates, it is estimated that the total 

 gross erosion into the U.S. portion of Lake Superior is in excess of 4.8 

 million tons/yr. (a literature review of this subject will yield a wide 



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