Health risks from IPR ‘unlikely to be significant’ – study

The concentrations of residual contaminants in highly processed wastewaters in the USA that could be used for planned indirect potable reuse are, in general, so low that that it is unlikely that there would be any significant risks to health.

This is the principal conclusion of a report on health-related effects of reuse just published by the WateReuse Association.

The project Health Effects Concerns of Water Reuse with Research Recommendations (WRA-06-004-1) evaluated information on the chemical composition of wastewaters at several levels of processing ranging from tertiary treatment to membranes and advanced oxidation and soil treatments. Toxicity screening methods were applied to identify residual chemicals that might be a health concern, based on their estimated toxicity and concentrations.

For the selected chemicals and groups, studies were identified that would provide an enhanced basis for risk assessment for low exposures from drinking water. Draft nomination packages were prepared and submitted to several federal agencies’ research programs to encourage them to carry out the studies that would provide important information for risk assessments that would provide the basis for evaluating residual contaminants in recycled water that might be a health concern for human exposure.

Despite its principal conclusion, the report does identify types and families of chemicals where additional toxicology studies are warranted, because of actual or probable presence in highly processed wastewaters and inadequate data to determine if there is a health hazard.