tional locations: the Microwave Tower, Flaxville, the TV Tower, Four 

 Buttes, and Scobey Downtown. The objectives were to use sulfation 

 rates to obtain a broad geographical indication of sulfur dioxide 

 concentrations and to investigate the relationship between sulfation 

 rate and sulfur dioxide concentrations. Montana anticipates that 

 funding will not be available in the future for continuous sulfur 

 dioxide monitoring. Therefore, Montana hoped that sulfation rate 

 might prove to be an inexpensive substitute. 



Over the last 6 months of 1984, sulfation rates were only slightly 

 above detectable levels. The highest monthly value was 0.080 "nilli- 

 gram per 100 centimetre squared per day (mg/100 cm^/day) at the 

 Scobey downtown site during November. Although levels were low, 

 there appears to be a direct relationship between sulfation rate and 

 sulfur dioxide at the Border site. Similar data from the Hanrahan 

 site indicates no relationship. 



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