Standards for chemical quality of drinking water: a critical assessment.

The author critically reviews present standards for the chemical quality of drinking water, particularly the limits proposed by the Commission of the European Communities (CEC) in 1979. Particularly, the general principles of standard setting are discussed. It appears that there exists a surprisingly high similarity in drinking water limits, issued by various national and international authorities, although for other environmental compartments important discrepancies exist. Usually, drinking water limits lack adequate documentation, and appear often to be copied from other existing lists. There is an apparent lack of logical consistency in limits set for food, ambient or workroom air, and drinking water, probably due to lack of communication between health experts and decision-making authorities. Moreover, there is a lack of toxicologic studies, explicitly aimed at setting limits. Extrapolation from the acceptable daily intakes (ADI) for food or the Threshold Limit Value (TLV)-Maximum Acceptable Concentration (MAC) for workroom air could be undertaken to derive tentative drinking water limits, as long as explicitly designed studies for drinking water are not yet available.