Minimizing Pollution

Your article “Tainted Salvage Yard Water Pumped Into Sewer” (Jan 29.) contributes to the continuing deception, fostered on a naive public by proponents of the infamous Proposition 65.

Use of a statement such as “Levels of benzene . . . are considered unacceptable at more than 0.7 parts per billion” is totally without scientific significance.

Any significant measurement must be accompanied by three criteria. Your article did not include these. They are:

Accuracy--This tells the observer how a measurement can be traced to an accepted standard of measurement.

Repeatability--This tells the observer how frequently the measurement techniques gave the same results.

Accountability--This explains the methodology used to obtain the results.

By applying these criteria, a trained observer is able to duplicate the measurement technique and verify the results. Without this knowledge, a number is just a number without significance. Dr. Bruce Ames, distinguished chairman of the biochemistry department at UC Berkeley, once tried to point this out in your newspaper. “One part per billion,” he wrote, “is one person in all of China.” I know nothing about biochemistry, but as an engineer intimately concerned with measurement techniques, I do know measurements.

One part per billion may be represented by one red golf ball, in a straight line of white golf balls, each touching two others. A billion golf balls, so arranged, would stretch 26,300 miles, and would more than encircle the earth. How would you measure this one part per billion? Not by sampling techniques. You’d have to count the balls!

Proposition 65 pretends to protect the public from toxics in the environment by making the preposterous presumption that these toxics can be measured at concentrations of parts per billion. No laboratory can substantiate such accuracy by a discrete number--indeed, few can justify such accuracies, repeatabilities and accountabilities in the parts per million categories. Let us not perpetuate these absurdities!

TOM B. STEPHENSON

San Juan Capistrano