Drinking-Water Guidelines

It is noted that the problems associated with chemical constiments of drinking water arise primarily from their ability to cause adverse health effects after prolonged periods of exposure, and 

In some instances, provisional guideline values have been set for constiments for which there is some evidence of a potential hazard but where the available information on health effects is limited. Provisional guideline values have also been set for substances for which the calculated guideline value would be below the practical quantification level, or below the level that can be achieved through practical treatment methods, as well as for certain substances when it is likely that guideline values will be exceeded as a result of disinfection procedures. 

It is stated that thousands of chemicals have been identified in drinking-water supplies around the world, many in extremely low concentrations. The chemicals selected for the development of guideline values include those considered potentially hazardous to human health, those detected relatively frequently in drinking water, and those detected in relatively high concentrations. 

Chapter 12 of Volume 2, second edition (WHO 1996), gives a detailed and comprehensive description of the principles used in estabfishing the guideline values. 

The assessment of the toxicity of drinking-water contaminants has been made on the basis of published reports from the open literamre, information submitted by governments and other interested parties, and unpublished proprietary data. In the development of the guideline values, existing international approaches to developing guidelines were carefully considered. Previous risk assessments developed by the WHO/IPCS in EHC monographs (see Section 3.6.1.1), lARC (see Section 3.6.1.2), JMPR (see Section 3.6.1.3), and JECFA (see Section 3.6.1.3) were reviewed. These assessments were relied upon except where new information justified a reassessment. The quality of new data was critically evaluated prior to their use in risk assessment. 

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WHO Drinking-water guideline values for health-related organics None WHO 1984... 

The European drinking water guidelines set a maximum admissible concentration of 0.10 pgL for individual pesticides and their related compounds in drinking water. The recommended methods for oxime carbamates and their metabolites in groundwater and surface water are suitable for detection limits below 0.10 pgL. The first method is the HPLC/lluorescence multiresidue method of de Kok et al The second method is an HPLC/MS/MS method of DuPont Crop Protection which is specific for oxamyl and may be applicable for the analysis of other oxime carbamates in heavily polluted waters. 

Compound name Chemical group Current UK usage (tonnes/a) Rate of application (kg/ha) Water solubility (mg/l) Physical class Pollution hazard class " Drink water guideline (PgH)... 

NOTE Update of drinking water guidelines and other areas in progress. 

WHO Drinking-water guideline values-chemlcals of health significance 300 g/L WHO 1996... 

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