THE DYNAMICS OF LEAD IN DRINKING-WATER IN UNITED-STATES WORKPLACES AND SCHOOLS

A statistical analysis of water samples from over 12,000 school and wo rkplace water coolers, bubblers, chillers, faucets, and ice makers det ermined that there is a substantial risk of excessive lead concentrati ons in first-draw water from sources of all types. Of all sources test ed, 17.2% had lead concentrations in excess of 15 ppb. A comparison of lead concentrations by brand of water cooler was made for all manufac turers for which at least 50 samples were available. The percentage of water sources with first-draw lead concentrations above 15 ppb was re duced by 58%-84% by flushing the source prior to use. Special attentio n was given to determining the relationships between lead levels and f actors such as water pH, water cooler age, and line purging. While eac h of these variables was found to be statistically significant, the ov erwhelming indication of this research is that testing individual wate r sources is apparently the only reliable way to determine whether a l ead contamination problem exists.