AWWA JAW59813

This article presents an approach to describing the presence of measurable pharmaceutical residuals originating in municipal sewage, which in turn provides a means of predicting the likely appearance of individual contaminants in effluents and downstream water sources. Trace organic contaminants come from many sources in wastewater. Their health significance is unknown and a problem for toxicologists to define. Analytical technology now enables measurement of many organic contaminants at very low concentrations and for which no adequate understanding of health significance has been developed. The study was conducted to show how a class of contaminants (pharmaceutical residuals) can be described and to demonstrate the presence of unmeasurable residuals. Regulators will increasingly be faced with pressure to assure safety without a clear toxicological basis for measuring risk. This work provides a blueprint for describing the presence and distribution of other groups of trace organic contaminants. It also underscores the urgent need for development of fundamental toxicological principles for assessing potential significance to human health from exposure to trace and ultratrace contaminants and mixtures.