TRACE ELEMENTS IN WATER AND CARDIOVASCULAR DISEASE - POPULATION EXPOSURE TO METALS RELEASED FROM PIPING MATERIALS USED FOR WATER DISTRIBUTION IN THE UK (H0156C) Final Report to The Department of the Environment 1977-1981
Report No DWI0091

Jan 1982

SUMMARY

This is the final report on those parts of Project 0156 addressed to the following objectives:

1. To investigate the relationship between the chemical composition (in particular the trace element content) of distributed waters at the tap and the characteristics of the source water and of the treatment, distribution and household plumbing systems.

2. To investigate and evaluate methods of estimating population exposure to drinking water constituents, with particular reference to trace elements.

The concentrations of 26 elements in tap-water were surveyed at 40 houses in each of 25 towns, and have been combined with corresponding data on the consumption of tap-water based drinks to provide estimated intakes for middle-aged men. The concentrations of lead, copper and zinc in drinking water were also studied in relation to the quality of water from source, and pH appeared to be the most important water quality factor controlling levels of these metals in tap-water.

The ways in which lead and copper concentrations are related to stagnation time and flow-rate were investigated in detail at 7 locations. Stagnation time was shown to have an important effect on concentration but flow-rate less so.

A comparison of sampling methods for lead demonstrated the unreliability of discrete random samples for estimating mean intake. A proportional composite sampling device was evaluated on a limited scale.

A method of combining information on stagnation curves with information on the statistical distribution of inter-use stagnation times was developed and shown to provide a feasible approach to estimating the exposure of population groups.

Copies of this report may be available as an Acrobat pdf download under the 'Find Completed Research' heading on the DWI website.