In. situ recovery of oil from sulphur-bearing de- posits and subsequent processing to produce petroleum products necessitates the removal, handling, and disposal of sulphur by-products. Containment and recovery of sulphur are important goals from both the resource management and environmental protection viewpoints. Knowing the environmental effects of sulphur compounds allows industry to make informed and intelligent decisions on how much sulphur to contain and how much to release as an aerially dis- persed waste.
Due to the nature of sulphur in oil deposits, and the process employed for oil extraction, a part of the sulphur is converted to S02 and is emitted into the atmosphere. To date the petroleum industry in Canada in general and the oil sands recovery industry in particular have acted in a responsible manner in containment of sulphur compounds and in the release of aerial sulphides. Historically, however, North America and Europe have suffered considerably from sulphurous gas releases that have destroyed vast areas of forest and contaminated lands and lakes. Current global concerns were summarized by Dochinger and Seligo (1976) in the proceedings of the first inter- national symposium on acid precipitation and the forest ecosystem thus:
Major findings presented at the Symposium indicated that: (1) precipitation is becoming increasingly acidic in northwestern Europe, northeastern United States and eastern Canada; (2) this increase is related to greater emissions of sulphur and other acid- forming compounds into the atmosphere from various industrial and urban sources; (3) the acidity may be associated with both indigenous and remote sources;
(4) the acidifying pollutants are deposited on the land in both wet and dry forms; (5) serious effects of acid precipitation have been observed in Scandinavia and North America. In addition to major impacts already identified, such as loss of fisheries and changes in some forest ecosystems, scientists at the Symposium expressed concern for other more subtle, long- term effects on the biosphere which might result from acid precipitation.