The public health significance of trace chemicals in waste water utilization.

The practice of waste water utilization has grown considerably in recent years, owing to the growing demand for water for agricultural, industrial and domestic purposes. Such utilization presents certain problems in respect of the quality of the reclaimed water, on account of the presence of certain trace chemicals in the waste waters to be re-used. The presence of these trace chemicals may have important consequences in the agricultural or industrial utilization of waste waters, but from the public health point of view it is in the re-use of waste waters for domestic purposes that their presence has most importance, owing to their possible toxic effects.This paper discusses the public health significance of trace chemicals in water, with special reference to some of the newer complex synthetic organic compounds that are appearing in ever-increasing numbers in industrial wastes. Current information on the acute and chronic toxicity of these substances is reviewed and related to possible methods of treatment of waste waters.In conclusion, the author points out that the problem of trace chemicals is not confined only to direct waste-water reclamation projects, but arises in all cases where surface waters polluted with industrial wastes are used as a source of domestic supply.